ORIGINAL_ARTICLE
Addition of a second alcohol in magnesium ethoxide synthesis as a way to vary the pore architecture of Ziegler-Natta catalysts
In Ziegler-Natta olefin polymerization, the pore architecture of catalysts plays a crucial role in catalytic performances and polymer properties. While the type of preparation routes (such as chemical reaction and solution precipitation) greatly affects the catalyst pore architecture as a result of different solidification mechanisms, the modification of the pore architecture within a given route has been hardly achieved. In this study, we propose a simple way to vary the pore architecture of Mg(OEt)2-based Ziegler-Natta catalysts by the addition of a second alcohol. It was found that the addition of a second alcohol during Mg(OEt)2 synthesis affected not only the morphology of Mg(OEt)2 macroparticles but also the shape of building units. The degree of alternation was found to be sensitive to the molecular structure of a second alcohol. Noticeable influences were observed in the case of branched alcohols, where the transformation of plate-like building units to cylindrical ones led to the generation of totally different pore size distributions of resultant catalysts.
http://poj.ippi.ac.ir/article_1131_d3206454629de1a26c280525c722d0fe.pdf
2015-06-01
65
71
10.22063/poj.2015.1131
Ziegler-Natta catalysts
pore architecture
magnesium alkoxide
Toshiaki
Funako
s1240012@jaist.ac.jp
1
School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
AUTHOR
Patchanee
Chammingkwan
chamming@jaist.ac.jp
2
School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
AUTHOR
Toshiaki
Taniike
taniike@jaist.ac.jp
3
School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
AUTHOR
Minoru
Terano
terano@jaist.ac.jp
4
School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1211, Japan
LEAD_AUTHOR
Soga K, Shiono T (1997) Ziegler-Natta catalysts for olefin polymerizations. Prog Polym Sci 22: 1503-1546
1
Hadian N, Hakim S, Nekoomanesh-Haghighi M, Bahri-Laleh N (2014) Storage time effect on dynamic structure of MgCl2.nEtOH adducts in heterogeneous Ziegler-Natta catalysts. Polyolefins J 1: 33-41
2
Dil EJ, Pourmahdian S, Vatankhah M, Afshar Taromi F (2010) Effect of dealcoholation of support in MgCl2-supported Ziegler–Natta catalysts on catalyst activity and polypropylene powder morphology. Polym Bull 64: 445-457
3
Terano M, Murai A, Inoue M, Miyosi K (1987) JP1987158704 (to Toho Catalyst Co. Ltd.)
4
Nitta T, Liu B, Nakatani H, Terano M (2002) Formation, deactivation and transformation of stereospecific active sites on TiCl4/ dibutylphthalate/Mg(OEt)2 catalyst induced by short time reaction with Al-alkyl cocatalyst. J Mol Catal A: Chem 180: 25-34
5
Pokasermsong P, Praserthdam P (2009) Comparison of activity of Ziegler-Natta catalysts prepared by recrystallization and chemical reaction methods towards polymerization of ethylene. Eng J 13: 57-64
6
Tanase S, Katayama K, Inasawa S, Okada F, Yamaguchi Y, Sadashima T, Yabunouchi N, Konakazawa T, Junke T, Ishihara N (2008) New synthesis method using magnesium alkoxides as carrier materials for Ziegler-Natta catalysts with spherical morphology. Macromol React Eng 2: 233-239
7
Zheng X, Pimplapure MS, Weickert G, Loos J (2006) Influence of copolymerization on fragmentation behavior using Ziegler-Natta catalysts. Macromol Rapid Commun 27: 15-20
8
Dashti A, Ramazani SA, Hiraoka Y, Kim SY, Taniike T, Terano M (2009) Kinetic and morphological study of a magnesium ethoxide based Ziegler–Natta catalyst for propylene polymerization. Polym Int 58: 40-45
9
Ko YS, Woo SI (2003) Shape and diffusion of the monomer-controlled copolymerization of ethylene and α-olefins over Cp2ZrCl2 confined in the nanospace of the supercage of NaY. J Polym Sci A: Polym Chem 41: 2171-2179
10
Taniike T, Funako T, Terano M (2014) Multilateral characterization for industrial Ziegler–Natta catalysts toward elucidation of structure-performance relationship. J Catal 311: 33-40
11
Chammingkwan P, Thang VQ, Terano M, Taniike T (2014) MgO/MgCl2/TiCl4 core-Shell catalyst for establishing structure-performance relationship in Ziegler-Natta olefin polymerization. Top Catal 57: 911-917
12
Poonpong S, Dwivedi S, Taniike T, Terano M (2014) Structure-performance relationship for dialkyldimethoxysilane as an external donor in stopped-flow propylene polymerization using a Ziegler-Natta catalyst. Macromol Chem Phys 215: 1721-1727
13
Barrett EP, Joyner LG, Halenda PH (1951) The determination of pore volume and area distributions in porous substances. I. Computations from nitrogen isotherms. J Am Chem Soc 73: 373-380
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Innes WB (1957) Use of parallel plate model in calculation of pore size distribution. Anal Chem 29: 1069-1073
15
Tanase S, Katayama K, Inasawa S, Okada F, Yamaguchi Y, Konakazawa T, Junke T, Ishihara N (2008) Particle growth of magnesium alkoxide as a carrier material for polypropylene polymerization catalyst. Appl Catal A: Gen 350: 197-206
16
Sing KSW, Everett DH, Haul RAW, Moscou L, Pierotti RA, Rouquérol J, Siemieniewska T (1985) Physical and biophysical chemistry division commission on colloid and surface chemistry including catalysis. Pure Appl Chem 57: 603-619
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Horvath G, Kawazoe K (1983) Method for the calculation of effective pore size distribution in molecular sieve carbon. J Chem Eng Japan 16: 470-475
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Saito A, Foley HC (1995) Argon porosimetry of selected molecular sieves: experiments and examination of the adapted Horvath-Kawazoe model. Microporous Mater 3: 531-542
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Taniike T, Chammingkwan P, Thang VQ, Funako T, Terano M (2012) Validation of BET specific surface area for heterogeneous Ziegler-Natta catalysts based on αs-plot. Appl Catal A: Gen 437-438: 24-27
21
ORIGINAL_ARTICLE
Study of Ziegler-Natta/(2-PhInd)2ZrCl2 hybrid catalysts performance in slurry propylene polymerization
Several types of hybrid catalysts are made through mixing of 4th generation Ziegler-Natta (ZN) and (2-PhInd)2ZrCl2 metallocene catalysts using triethylaluminum (TEA) as coupling agent. Response surface methodology (RSM) is used to evaluate the interactive effects of different parameters including amounts of metallocene and TEA and temperature on metallocene loading. Analyzing the amounts of Al and Zr elements in the hybrid catalysts through ICP-OES and EDXA reveals that temperature plays a crucial role on anchoring of the metallocene catalyst on ZN while TEA has the least determining effect. The ICP analysis shows that as the concentration of Al goes up in the hybrid catalyst the concentration of Zr passes a maximum, while EDXA shows a direct relationship between the Al and Zr contents. Using triisobutylaluminum (TIBA) and methylaluminoxane (MAO) as the coupling agents, almost similar metallocene loadings are observed. Finally, the performance of hybrid catalysts is investigated in propylene polymerization and the obtained polymers are characterized using DSC and DMTA through which the presence of two types of polymers in the final product are confirmed.
http://poj.ippi.ac.ir/article_1145_37a49082a2bc170a27aa700414df433d.pdf
2015-06-01
73
87
10.22063/poj.2015.1145
Hybrid catalysts
Ziegler-Natta
metallocene
Surface and bulk analysis
Polypropylene
Gholam-Reza
Nejabat
ghnejabat@yahoo.com
1
Department of Polymer engineering, School of Chemical and Material Engineering, Islamic Azad University (Shiraz Branch), P.O. Box. 71993-3, Shiraz, Iran
LEAD_AUTHOR
Mehdi
Nekoomanesh
m.nekoomanesh@ippi.ac.ir
2
Polymerization Engineering Department, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran
LEAD_AUTHOR
Hassan
Arabi
h.arabi@ippi.ac.ir
3
Polymerization Engineering Department, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran
AUTHOR
Hamid
Salehi-Mobarakeh
h.salehi@ippi.ac.ir
4
Petrochemical Department, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran
AUTHOR
Gholam-Hossein
Zohuri
zohuri@um.ac.ir
5
Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, P.O. Box 1436, Mashhad, Iran
AUTHOR
Mohammad-Mahdi
Mortazavi
m.mortazavi@ippi.ac.ir
6
Polymerization Engineering Department, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran
AUTHOR
Saeid
Ahmadjo
7
Catalyst Department, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran
AUTHOR
Stephen
Miller
miller@chem.ufl.edu
8
The George and Josephine Butler Polymer Research Laboratory, Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA
AUTHOR
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Lόpez-Linares F, Barrios AD, Ortega H, Matos JO, Joskowicz P, Agrifoglio G (2000) Toward the bimodality of polyethylene, initiated with a mixture of a Ziegler-Natta and metallocene/MAO catalyst system. J Mol Catal A: Chem 159: 269-272
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Marquez MFV, Chaves EG (2003) Polypropylene fractions produced by binary metallocene catalysts. J Polym Sci Part A: Polym Chem 41: 1478-1485
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Marquez MFV, Pombo CC, Silva RA, Conte A (2002) Supported stereospecific metallocene binary catalyst for propylene polymerization. J Polym Sci Part A: Polym Chem 40: 2979-2986
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Marquez MFV, Pombo CC, Silva RA, Conte A (2003) Binary metallocene supported catalyst for propylene polymerization. Eur Polym J 39: 561- 567
23
Marques MFV, Conte A (2006) Propylene polymerization using combined syndio and isospecific metallocene catalysts supported on silica/MAO J Appl Polym Sci 99: 628-637
24
Tynys A, Saarinen T, Bartke M, Lofgren B (2007) Propylene polymerisations with novel heterogenous combination metallocene catalyst systems. Polymer 48: 1893-1902
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Li W, Wang J, Jiang B, Yanga Y, Jieb Z (2010) Ethylene polymerization with hybrid nickel diimine/Cp2TiCl2 catalyst: A new method to prepare blends of linear and branched polyethylene. Polym Int 59: 617-623
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28
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Mota FF, Mauler RS, Souza RF, Casagrande Junior OL (2003) Production of LPE/BPE blends using homogeneous binary catalyst system: influence of the polymerization parameters on polymer properties. Polymer 44: 4127-4133
30
Ye Z, Zhu S (2003) Synthesis of branched polypropylene with isotactic backbone and atactic side chains by binary iron and zirconium single-site catalysts. J Polym Sci Part A: Polym Chem 41: 1152-1159
31
Pan L, Zhang KY, Li YG, Bo SQ, Li YS (2007) Thermal and crystallization behaviors of polyethylene blends synthesized by binary late transition metal catalysts combinations. J Appl Polym Sci 104: 4188-4198
32
Nassiri H, Arabi H, Hakim S, Bolandi S (2011) Polymerization of propylene with Ziegler-Natta catalyst: optimization of operating conditions by response surface methodology. Polym Bull 67: 1393-1411
33
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Nejabat GR, Nekoomanesh M, Arabi H, Salehi- Mobarakeh H, Zohuri GH, Omidvar M, Miller SA (2012) Synthesis of stereoblock elastomeric poly(propylene)s using a (2-PhInd)2ZrCl2 metallocene catalyst in the presence of co-catalyst mixtures, 1-study of activity and molecular weight. Macromol React Eng 6: 523-529
35
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38
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39
Nejabat GR, Nekoomanesh M, Arabi H, Salehi- Mobarakeh H, Zohuri GH, Omidvar M, Miller SA (2013) Synthesis and microstructural study of stereoblock elastomeric polypropylenes from metallocene catalyst (2-PhInd)2ZrCl2 activated with cocatalyst mixtures. J Polym Sci Part A: Polym Chem 51: 724-731
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45
ORIGINAL_ARTICLE
Reaction dynamics during the testing of polymerization catalyst
The olefins polymerization process in a slurry reactor is discussed. The reaction rate dynamics was analyzed and the contributions of feed flow, gas-liquid mass transfer, polymerization reaction, and catalyst deactivation were estimated. The propylene solubility in a solvent mixture “heptane” was calculated using Soave-Redlich-Kwong equation of state. These data were then approximated by Henry-like equation and the results were verified in experiments. The influence of propylene dissolving in ”heptane which was examined in special experiments without catalyst has provided the independent estimation of gas-liquid mass transfer coefficient. It has been shown that the reaction rate during the first 20-30 min of test is much lower (or higher) than total monomer consumption, depending on reactant addition sequence. The method of kinetic experiments interpretation and corresponding mathematical model are proposed. The method enables to estimate the kinetic parameter of monomer dissolution, the reaction rate constant of polymerization, as well as the parameters of active centers transformation – activation, deactivation and self-regeneration. An adequacy of model was proved by the description of experiments at two different pressures but with the same parameters values.
http://poj.ippi.ac.ir/article_1156_db0223822d19c4f83ce3ec734497799d.pdf
2015-06-01
89
97
10.22063/poj.2015.1156
reaction dynamics
Propylene polymerization
catalyst testing
Nickolay
Ostrovskii
nikolaj.ostrovski@hipol.rs
1
HIPOL a.d., Gračački put b.b., Odžaci 25250, Serbia
LEAD_AUTHOR
Ladislav
Fekete
ladislav.fekete@hipol.rs
2
HIPOL a.d., Gračački put b.b., Odžaci 25250, Serbia
AUTHOR
Albizzati E, Cecchin G, Chadwick JC, Collina G, Giannini U, Morini G, Noristi L (2005) Ziegler- Natta catalysts and polymerizations. In: Polypropylene handbook, Hanser, Munich, 15- 106
1
Nagel EJ, Kirillov VA, Ray WH (1980) Prediction of molecular weight distributions for high density polyolefins. Ind Eng Chem Prod Des Dev 19: 372-379
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3
McKenna TF, Soares JBP (2001) Single particle modeling for olefin polymerization on supported catalysts: A review and proposals for future developments. Chem Eng Sci 56: 3931- 3949
4
Najafi M, Parvazinia M, Ghoreishy HR, Kiparissides C (2014) Development of a 2D single particle model to analyze the effect of initial particle shape and breakage in olefin polymerization. Macromol React Eng 8: 29-45
5
Ostrovskii NM, Kenig F (2005) About mechanism and model of deactivation of Ziegler–Natta polymerization catalysts. Chem Eng J 107: 73-77
6
Floyd S, Choi KY, Taylor TW, Ray WH (1986) Polymerization of olefins through heterogeneous catalysis.III. Polymer particle modelling with an analysis of intraparticle heat and mass transfer effects. J Appl Polym Sci 32: 2935-2960
7
Debling JA, Ray WH (1995) Heat and mass transfer effects in multistage polymerization process: Impact polypropylene. Ind Eng Chem Res 34: 3466-3480
8
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9
Kyoung-Su Ha, Kee-Youn Yoo, Hyun-Ku Rhee (2001) Modeling and analysis of a slurry reactor system for heterogeneous olefin polymerization: The effects of hydrogen concentration and initial catalyst size, J Appl Polym Sci 79: 2480-2493
10
Jin-San Yoon, Ray WH (1987) Simple mechanistic model for the kinetics and catalyst activity decay of propylene polymerization over TiCl3 catalyst with DEAC cocatalyst. Ind Eng Chem Res 26: 415-422
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Magni E, Malizija F, Somorjai GA (1998) Surface science toward single site heterogeneous polypropylene catalysis. In: Polypropylene – Past, present and future: The challenge continues. Ferrara, Italia, 179-203
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Dumas C, Hsu CC (1989) Propylene polymerization in a semibatch slurry reactor over supported TiCl4/MgCl2/Ethyl Bensoate/ Triethyl Aluminium catalyst. I. Catalytic behaviour. J Appl Polym Sci 37: 1605-1623
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Reid RC, Prausnitz JM, Sherwood TK (1977) The properties of gases and liquids. McGrow-Hill
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Natta G (1959) Kinetic studies of a-olefin polymerization. J Polym Sci 34: 21-48
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Keii T (1986) Mechanistic studies on Ziegler- Natta catalysis: A methodological reconsideration. In: Catalytic polymerization of olefins. Elsevier, Amsterdam, 1-27
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Lim SY, Choung SJ (1997) Studies on the catalytic deactivation in propylene polymerization. Appl Catal A: General 153: 103-118
20
Ostrovskii NM, Fekete L (2014) Process dynamics in slurry polymerization. In: Proceeding of the 12th international conference of physical chemistry, Belgrade, Serbia, 207–214
21
Dompazis G, Kanellopoulos V, Kiparissides C (2005) A multi-scale modeling approach for the prediction of molecular and morphological properties in multi-site catalyst, olefin polymerization reactors. Macromol Mater Eng 290: 525-536
22
Liu X (2007) Modeling and simulation of heterogeneous catalyzed propylene polymerization. Chinese J Chem Eng 15: 545-553
23
ORIGINAL_ARTICLE
An investigation on non-isothermal crystallization behavior and morphology of polyamide 6/ poly(ethylene-co-1-butene)-graft-maleic anhydride/organoclay nanocomposites
Nanocomposites based on polyamide 6 (PA6) and poly(ethylene-co-1-butene)-graft-maleic anhydride (EB-g- MAH) blends have been prepared via melt mixing. The effect of blend ratio and organoclay concentration on the crystallization and melting behavior of specimens were studied. Three types of commercial organo-modified clay (Cloisite 30B, Cloisite 15A and Cloisite 20A) were employed to assess the importance of the nanoclay polarity and gallery distance. The crystallization behavior was investigated using differential scanning calorimetry (DSC) and wide angle X-ray diffraction spectroscopy (WAXD). The strong interactions between amine end groups of PA6 and maleic anhydride groups of EB-g-MAH led to complete inhibition of EB-g-MAH crystallization according to the DSC results. A transformation from the α form to the γ form crystals of PA6, induced by both organoclays and EB-g-MAH, was monitored by WAXD and DSC. Small angle X-ray scattering (SAXS) was used to evaluate the morphology of nanocomposites. Moreover, transmission electron microscopy (TEM) was conducted to determine the location of organoclays and indicated that the organoclays mainly present in the PA6 matrix and rarely distribute in the EB-g-MAH phase in the case of low polarity organoclays. It was also evidenced that the organoclay with the most affinity to PA6 (Cloisite 30B) had the largest effect on the thermal and crystallization behavior of this phase in the blend.
http://poj.ippi.ac.ir/article_1164_c767bdf98fc8d9d7579c4ad1e3193b12.pdf
2015-06-01
99
108
10.22063/poj.2015.1164
polyamide 6
polyolefin elastomer
organoclay
crystallization
morphology
Sepideh
Gomari
s.gomari@ippi.ac.ir
1
Plastic Department, Iran Polymer and Petrochemical Institute, P.O.Box: 14965/115, Tehran, Iran.
AUTHOR
Ismaeil
Ghasemi
i.ghasemi@ippi.ac.ir
2
Plastic Department, Iran Polymer and Petrochemical Institute, P.O.Box: 14965/115, Tehran, Iran.
LEAD_AUTHOR
Mohammad
Karrabi
m.karabi@ippi.ac.ir
3
Plastic Department, Iran Polymer and Petrochemical Institute, P.O.Box: 14965/115, Tehran, Iran.
AUTHOR
Hamed
Azizi
h.azizi@ippi.ac.ir
4
Plastic Department, Iran Polymer and Petrochemical Institute, P.O.Box: 14965/115, Tehran, Iran.
AUTHOR
Gonzalez I, Eguiazabal J, Nazabal J (2005) Compatibilization level effects on the structure and mechanical properties of rubber modified polyamide 6/clay nanocomposites. J Polym Sci B: Polym Phys 43: 3611-3620
1
Huang J, Keskkula H, Paul D (2006) Comparison of the toughening behavior of nylon 6 versus an amorphous polyamide using various maleated elastomers. Polymer 47: 639-651
2
Chen X, Yu J, Luo Z, Guo S, He M, Zhou Z (2011) Study on mechanical properties and phase morphology of polypropylene/polyolefin elastomer/magnesium hydroxide ternary composites. Polym Adv Technol 22: 657-663
3
Qiu G, Liu G, Qiu W, Liu S (2013) Phase morphology and mechanical properties of polyamide-6/ polyolefin elastomer- g – maleic anhydride blends. J Macromol Sci, B 53: 615-624
4
Choi M, Jung J-Y, Chang Y-W (2014) Shape memory thermoplastic elastomer from maleated polyolefin elastomer and nylon 12 blends. Polym Bull 71: 625-635
5
Nishitani Y, Yamada Y, Ishii C, Sekiguchi I, Kitano T (2010) Effects of addition of functionalized SEBS on rheological, mechanical, and tribological properties of polyamide 6 nanocomposites. Polym Eng Sci 50: 100-112
6
Isik-gulsac I, Yilmazer U, Bayram G (2013) Effects of addition order of the components on polyamide-6/ organoclay/ elastomer ternary nanocomposites. Adv Polym Technol 32: E675-E691
7
Kohan MI, Kohan MI (1995). Nylon plastics handbook, Hanser Publishers
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9
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Brandrup J (1989) Polymer Handbook. 3rd ed. John Wiley and Sons, New York
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27
ORIGINAL_ARTICLE
The effect of high-energy electron beam on drawn and undrawn high density polyethylene fibers
HDPE monofilaments were obtained using different extruders and drawn by post-extruder equipments. After solidification, drawn and undrawn monofilaments (draw ratio 7:1) were irradiated with 10 MeV electron beams in air at room temperature at 25, 50, 75, 100 and 125 kGy dose ranges to induce a network structure. HDPE crosslinking was studied on the basis of gel content measurements. The fibers were examined by differential scanning calorimetry (DSC) and measurements of mechanical properties.It was noted that gel fraction increased with irradiation dose up to 75 kGy and showed a significant increase with draw ratio, but at higher doses remained without considerable change. Melting temperature of drawn fiber increased with raising irradiation dose but decreased in undrawn sample. Also a bimodal endotherm peak was observed for drawn polyethylene irradiated in air.The changes in melting temperature and appearance of bimodal endotherm were related to the radiation chemistry of polyethylene in the presence of oxygen and interlamellar interactions. Heat of fusion and degree of crystallinity slightly increased for undrawn and drawn samples but, heat of crystallization was reduced by increasing irradiation dose due to increase the degree of crosslinking. Results of mechanical properties reveal that no significant changes seen in Young’s modulus by increasing irradiation dose. As a result of oxidative degradation happened by presence the oxygen molecules during the irradiation process, tensile properties of irradiated fibers decreased but elongation at yield for undrawn and elongation at break for drawn fibers boosted by increasing irradiation dose up to 125 kGy.
http://poj.ippi.ac.ir/article_1166_d88807ea89141051ba9f28c4a2fe7465.pdf
2015-06-01
109
119
10.22063/poj.2015.1166
polyethylene fiber
electron beam
crosslinking
draw ratio
Jalil
Morshedian
j.morshedian@ippi.ac.ir
1
Faculty of Processing, Iran Polymer and Petrochemical Institute, P.O. Box 14975/112, Tehran, Iran
LEAD_AUTHOR
Yousef
Jahani
y.jahani@ippi.ac.ir
2
Faculty of Processing, Iran Polymer and Petrochemical Institute, P.O. Box 14975/112, Tehran, Iran
AUTHOR
Farshad
Sharbafian
farshad_mc2@yahoo.com
3
Islamic Azad University of Tehran
AUTHOR
Foroogh Sadat
Zarei
zarei.foroogh@ut.ac.ir
4
Tehran University
AUTHOR
Ladizesky NH (1986) The drawing behavior of linear polyethylene: Effect of electron irradiation on drawing and subsequent mechanical behavior of drawn products. J Macromol Sci: Part B 25: 185-213
1
Woods DW, Busfield WK, Ward IM (1988) Improved mechanical-behavior in ultra high modulus polyethylene by controlled crosslinking. Polym Commun 29: 250-252
2
Galiatatos V, Eichinger BE (1988), Simulations on radiation-cured polyethylene. J Polym Sci: Part B 26: 595-602
3
Khonakdar HA (2006) Effect of electron-irradiation on cross-link density and crystalline structure of low- and high-density polyethylene. Rad Phys Chem 75: 78–86
4
Meola C (2003) Experimental evaluation of properties of cross-linked polyethylene. Mater Manuf Process 18: 135–144
5
Meola C (2004) Chemical and irradiation cross-linking of polyethylene. Technological performance over costs. Polym Plast Technol Eng 43: 631–648
6
Wünsche P (1984) Generation of free radicals by increasing the temperature after γ- irradiation of polyethylene. J Macromol Sci B 23: 65 – 84
7
Dole M (1981) History of the Irradiation Cross- Linking of Polyethylene. J Macromol Sci A 15: 1403-1409
8
Hikmet R, Keller A (1987) Crystallinity dependent free radical formation and decay in irradiated polyethylene in the presence of oxygen. Int J Rad Appl Instrum C 29: 15-19
9
Perez CJ, Vallés EM, Failla MD (2010) The effect of post-irradiation annealing on the crosslinking of high-density polyethylene induced by gamma-radiation. Rad Phys Chem 49: 710-715
10
Zaydouri A, Grivet M (2009) The effect of electron irradiation on high-density polyethylene: Positron annihilation lifetime spectroscopy, differential scanning calorimetry and X-ray scattering studies. Rad Phys Chem 78: 750-755
11
Dawes K (2007) The effects of electron beam and g-irradiation on polymeric materials In: Physical properties of polymers handbook, Mark JE (ed), 2nd ed., Springer Science
12
Adler G (1963) Cross-linking of polymer by radiation. Science 141: 321-329
13
Gheysari D (2001) The effect of high-energy electron beam on mechanical and thermal properties of LDPE and HDPE. Eur Polym J 37: 295-302
14
Perkins WG (1978) Effect of gamma radiation and annealing on ultra-oriented polyethylene. Polym Eng Sci 18: 527-532
15
Hu J (1999) Degradation of interpenetrating polymer networks based on PE and polymethacrylates by electron beam irradiation. Polymer 40: 5279–5284
16
Pearson RW (1957) Mechanism of the radiation crosslinking of polyethylene. J Polym Sci 25: 189-200
17
Zoepfl FJ (1984) Differential scanning calorimetry studies of irradiated polyethylene: I. Melting temperatures and fusion endotherms. J Polym Sci: Polym Chem 22: 2017–2032
18
Okada Y, Awemiya A (1961) Effect of atmosphere on radiation-induced crosslinking of polyethylene. J Polym Sci 50: 22-24
19
Okada Y (1963) Effect of atmosphere on radiation-induced crosslinking of polyethylene: III. Effect of various gases and effect of electric field. J Appl Polym Sci 7: 1153-1163
20
Carpentieri I (2011) Post-irradiation oxidation of different polyethylene. Polym Degrad Stabil 96: 624-629
21
Hama Y (2011) Long-term oxidative degradation in polyethylene irradiated with ion beams. Rad Phys Chem 62: 133-139
22
Seguchi T (1983) Radiation induced oxidative degradation of polymers: III. Effect of radiation on mechanical properties. Rad Phys Chem 21: 495-501
23
Black RM, Charlesby A (1959) The oxidation of irradiated polyethylene I radio-oxidation. Int J Appl Rad Isotope 7: 127-133
24
Narkis M (1987) Structure and tensile behavior of irradiation- and peroxide- crosslinked polyethylenes. J Macromol Sci B 26: 37- 58
25
Seguchi T (1983) Radiation induced oxidative degradation of polymers II. Effects of radiation on swelling and gel fraction of polymers. Rad Phys Chem 19: 495-501
26
Basfar AA, Ali KMI (2004) Effect of various additives on tensile properties of polyethylene films irradiated in air, water, N2, and vacuum. Polym Plast Technol Eng 43: 389–405
27
Klein PG (1987) The effect of electron irradiation on the structure and mechanical properties of highly drawn polyethylene fibers. J Polym Sci: Polym Phys 25: 1359-137
28
QU B, Ranby B (1995) Radiation crosslinking of polyethylene with electron beam at different temperatures. Polym Eng Sci 35: 1161-1166
29
Tillet G (2011) Chemical reactions of polymer crosslinking and post-crosslinking at room and medium temperature. Prog Polym Sci 36: 191-217
30
Gheysari D, Behjat A (2001) Radiation crosslinking of LDPE and HDPE with 5 and 10 MeV electron beams. Eur Polym J 37: 2011-2016
31
Akay G (1990) The effect of molecular orientation on gamma-radiation induced crosslinking in high density polyethylene. Rad Phys Chem 36: 337-343
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Kawai T (1965) The effect of crystallization conditions on radiation- induced crosslink formation in polyethylene. Philosoph Mag 12: 657-671
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36
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37
ORIGINAL_ARTICLE
Mathematical modeling the effect of catalyst initial shape and the crack pattern in olefin copolymerization
A two-dimensional (2D) single particle model for the copolymerization of propylene-ethylene with heterogeneous Ziegler-Natta catalyst is developed. The model accounts for the effects of the initial shape of the catalyst and carck/ pore patterns on the copolymer composition, polymerization rate and the average molecular weight properties. The spherical and oblate ellipsoidal shapes of catalyst particle and four different pattern distributions of cracks and pores in a growing particle are studied in this simulation. It is assumed that the diffusion coefficient of monomers in the cracks/pores is 10 times higher than the compact zone of the particle.In other word, the cracks are distinguished from parts with higher monomer diffusion coefficient.The dynamic 2D monomer diffusion-reaction equation is solved together with a two-site catalyst kinetic mechanism using the finite element method. Simulation results indicate that the initial shape of catalyst changes the average copolymer composition only in the early stage of polymerization, but the crack/pore patterns in the growing particle have a strong impact on the copolymer composition in the polymer particles due to the change ofmass transfer limitations.
http://poj.ippi.ac.ir/article_1165_b2df56b622f083cfcc23024846130f45.pdf
2015-06-01
121
133
10.22063/poj.2015.1165
single particle
modelling
finite element method
polyolefin
copolymerization
Marzieh
Nouri
marzieh_nouri1@yahoo.com
1
Iran Polymer and Petrochemical Institute (IPPI), P. O. Box 14975/112, Tehran, Iran
AUTHOR
Mahmoud
Parvazinia
m.parvazinia@ippi.ac.ir
2
Iran Polymer and Petrochemical Institute (IPPI), P. O. Box 14975/112, Tehran, Iran
LEAD_AUTHOR
Hassan
Arabi
h.arabi@ippi.ac.ir
3
Iran Polymer and Petrochemical Institute (IPPI), P. O. Box 14975/112, Tehran, Iran
AUTHOR
Mohsen
Najafi
najafi.m@qut.ac.ir
4
Qom University of Technology, P. O. Box 1519-37195, Qom, Iran
AUTHOR
McKenna TF, Soares JBP (2001) Single particle modelling for olefin polymerization on supported catalysts: A review and proposals for future developments. Chem Eng Sci 56: 3931-3949
1
Dube MA, Soares JBP, Penlidis A, Hamielec, JBP (1997) Mathematical modelling of multipcomponent chain-growth polymerizations in batch, semi-batch, and continuous reactors: A review. Ind Eng Chem Res 36: 966-1015
2
Mattos Neto AG, Pinto JC (2001) Steady state modeling of slurry and bulk propylene polymerization. Chem Eng Sci 56: 4043–4057
3
Schmeal WR, Street JR (1971) Polymerization in Expanding Catalyst Particles. AIChE J 17:1188-1197
4
Singh D, Merrill RP (1971) Molecular weight distribution of polyethylene produced by Ziegler- Natta catalysts. Macromolecules 4: 599-604
5
Kanellopoulos V, Dompazis G, Gustafsson B, Kiparissides C (2004) Comprehensive analysis of single-particle growth in heterogeneous olefin polymerization: The random-pore polymeric flow model. Ind Eng Chem Res 43: 5166-5180
6
Nagel EJ, Klrillov VA, Ray WH (1980) Prediction of molecular weight distributions for high-density polyolefins. Ind Eng Chem Prod Res Dev 79: 372-379
7
Floyd S, Choi KY, Taylor TW, Ray WH (1986) Polymerization of olefins through heterogeneous catalysis. III. Polymer particle modelling with an analysis of intraparticle heat and mass transfer effects. J Appl Polym Sci 32: 2935-2960
8
Galvan R, Tirrell M (1986) Molecular weight distribution predictions for heterogeneous Ziegler-Natta polymerization using a two-site model. Chem Eng Sci 41: 2385-2393
9
Hutchinson RA, Chen CM, Ray WH (1992) Polymerization of olefins through heterogeneous catalysts X: Modelling of particle growth and morphology. J Appl Polym Sci 44: 389-1414
10
Debling JA, Ray WH (1995) Heat and mass transfer effects in multistage polymerization processes: impact polypropylene. Ind Eng Chem Res 34: 3466-3480
11
Hoel EL, Cosewith C, Byrne GD (1994) Effect of diffusion on heterogeneous ethylene propylene copolymerization. AIChE J 40: 1669-1684
12
Sarkar P, Gupta SK (1991) Modelling of propylene polymerization in an isothermal slurry reactor. Polymer 32: 2842-2852
13
Chen Y, Liu X (2005) Modeling mass transport of propylene polymerization on Ziegler-Natta catalyst. Polymer 46: 9434-9442
14
Soares JBP, Hamielec AE (1995) General dynamic mathematical modeling of heterogeneous Ziegler- Natta and metallocene catalyzed copolymerization with multiple site types and mass and heat transfer resistances. Polym React Eng 3: 61-324
15
Wang W, Zheng ZW, Luo ZH (2011) Coupled single-particle and Monte Carlo model for propylene polymerization. J Appl Polym Sci 119: 352-362
16
Najafi M, Parvazinia M, Ghoreishy MH, Kiparissides C (2014) Development of a two dimensional finite element isothermal particle model to analyse the effect of initial particle shape and breakage in Ziegler-Natta olefin polymerization. Macromol React Eng 8: 29-45
17
Soares JBP (2001) Mathematical modeling of the microstructure of polyolefins made by coordination polymerization: A review. Chem Eng Sci 56: 4131-4153
18
Ahmadi M, Nekoomanesh M, Arabi H (2010) A simplified comprehensive kinetic scheme for modeling of ethylene/1-butene copolymerization using Ziegler-Natta catalysts. Macromol React Eng 4: 135-144
19
Soares JBP, McKenna T, Cheng CP (2007) In: Polymer reaction engineering, Asua JM (ed) 1st ed, Blackwell, Ch. 2, 29-117
20
Dompazis G, Kanellopoulos V, Touloupides V, Kiparissides C (2008) Development of a multiscale, multi-phase, multi-zone dynamic model for the prediction of particle segregation in catalytic olefin polymerization FBRs. Chem Eng Sci 63: 4735-4753
21
Soares JBP, Hamielec AE (1996) Copolymerization of olefins in a series of continuous stirred-tank slurry-reactors using heterogeneous Ziegler-Natta and metalocene catalysts. I. General dynamic mathematical model, Polym Reac Eng 4: 153-191
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Najafi M, Parvazinia M, Ghoreishy MH (2014) Modelling the effects of fragment patterns on molecular properties and particle overheating in olefin polymerization. Polyolefins J 1: 77-91
23
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24
Zubov A, Pechackova L, Seda L, Bobak M, Kosek J (2010) Transport and reaction in reconstructed porous polypropylene particle: Model validation. Chem Eng Sci 65: 2361-2372
25