Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
2
2
2015
06
01
Addition of a second alcohol in magnesium ethoxide synthesis as a way to vary the pore architecture of Ziegler-Natta catalysts
65
71
EN
Toshiaki
Funako
School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
s1240012@jaist.ac.jp
Patchanee
Chammingkwan
School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
chamming@jaist.ac.jp
Toshiaki
Taniike
School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
taniike@jaist.ac.jp
Minoru
Terano
School of Materials Science, Japan Advanced Institute of Science and Technology,
1-1 Asahidai, Nomi, Ishikawa 923-1211, Japan
terano@jaist.ac.jp
10.22063/poj.2015.1131
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)<sub>2</sub>-based Ziegler-Natta catalysts by the addition of a second alcohol. It was found that the addition of a second alcohol during Mg(OEt)<sub>2</sub> synthesis affected not only the morphology of Mg(OEt)<sub>2</sub> 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.
Ziegler-Natta catalysts,pore architecture,magnesium alkoxide
http://poj.ippi.ac.ir/article_1131.html
http://poj.ippi.ac.ir/article_1131_d3206454629de1a26c280525c722d0fe.pdf
Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
2
2
2015
06
01
Study of Ziegler-Natta/(2-PhInd)2ZrCl2 hybrid catalysts performance in slurry propylene polymerization
73
87
EN
Gholam-Reza
Nejabat
0000000167211011
Department of Polymer engineering, School of Chemical and Material Engineering, Islamic Azad University (Shiraz Branch), P.O. Box. 71993-3, Shiraz, Iran
ghnejabat@yahoo.com
Mehdi
Nekoomanesh
Polymerization Engineering Department, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran
m.nekoomanesh@ippi.ac.ir
Hassan
Arabi
Polymerization Engineering Department, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran
h.arabi@ippi.ac.ir
Hamid
Salehi-Mobarakeh
Petrochemical Department, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran
h.salehi@ippi.ac.ir
Gholam-Hossein
Zohuri
0000-0003-2380-8363
Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, P.O. Box 1436, Mashhad, Iran
zohuri@um.ac.ir
Mohammad-Mahdi
Mortazavi
0000-0002-6876-1063
Polymerization Engineering Department, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran
m.mortazavi@ippi.ac.ir
Saeid
Ahmadjo
Catalyst Department, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran
Stephen
A.
Miller
The George and Josephine Butler Polymer Research Laboratory, Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA
miller@chem.ufl.edu
10.22063/poj.2015.1145
Several types of hybrid catalysts are made through mixing of 4th generation Ziegler-Natta (ZN) and (2-PhInd)<sub>2</sub>ZrCl<sub>2 </sub> 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.
Hybrid catalysts,Ziegler-Natta,metallocene,Surface and bulk analysis,Polypropylene
http://poj.ippi.ac.ir/article_1145.html
http://poj.ippi.ac.ir/article_1145_37a49082a2bc170a27aa700414df433d.pdf
Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
2
2
2015
06
01
Reaction dynamics during the testing of polymerization catalyst
89
97
EN
Nickolay
Ostrovskii
HIPOL a.d., Gračački put b.b., Odžaci 25250, Serbia
nikolaj.ostrovski@hipol.rs
Ladislav
Fekete
HIPOL a.d., Gračački put b.b., Odžaci 25250, Serbia
ladislav.fekete@hipol.rs
10.22063/poj.2015.1156
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.
reaction dynamics,Propylene polymerization,catalyst testing
http://poj.ippi.ac.ir/article_1156.html
http://poj.ippi.ac.ir/article_1156_db0223822d19c4f83ce3ec734497799d.pdf
Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
2
2
2015
06
01
An investigation on non-isothermal crystallization behavior and morphology of polyamide 6/ poly(ethylene-co-1-butene)-graft-maleic anhydride/organoclay nanocomposites
99
108
EN
Sepideh
Gomari
Plastic Department, Iran Polymer and Petrochemical Institute, P.O.Box: 14965/115, Tehran, Iran.
s.gomari@ippi.ac.ir
Ismaeil
Ghasemi
Plastic Department, Iran Polymer and Petrochemical Institute, P.O.Box: 14965/115, Tehran, Iran.
i.ghasemi@ippi.ac.ir
Mohammad
Karrabi
Plastic Department, Iran Polymer and Petrochemical Institute, P.O.Box: 14965/115, Tehran, Iran.
m.karabi@ippi.ac.ir
Hamed
Azizi
Plastic Department, Iran Polymer and Petrochemical Institute, P.O.Box: 14965/115, Tehran, Iran.
h.azizi@ippi.ac.ir
10.22063/poj.2015.1164
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.
polyamide 6,polyolefin elastomer,organoclay,crystallization,morphology
http://poj.ippi.ac.ir/article_1164.html
http://poj.ippi.ac.ir/article_1164_c767bdf98fc8d9d7579c4ad1e3193b12.pdf
Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
2
2
2015
06
01
The effect of high-energy electron beam on drawn and undrawn high density polyethylene fibers
109
119
EN
Jalil
Morshedian
Faculty of Processing, Iran Polymer and Petrochemical Institute, P.O. Box 14975/112, Tehran, Iran
j.morshedian@ippi.ac.ir
Yousef
Jahani
0000-0001-5553-1915
Faculty of Processing, Iran Polymer and Petrochemical Institute, P.O. Box 14975/112, Tehran, Iran
y.jahani@ippi.ac.ir
Farshad
Sharbafian
Islamic Azad University of Tehran
farshad_mc2@yahoo.com
Foroogh Sadat
Zarei
Tehran University
zarei.foroogh@ut.ac.ir
10.22063/poj.2015.1166
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.<br />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.<br />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.
polyethylene fiber,electron beam,crosslinking,draw ratio
http://poj.ippi.ac.ir/article_1166.html
http://poj.ippi.ac.ir/article_1166_d88807ea89141051ba9f28c4a2fe7465.pdf
Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
2
2
2015
06
01
Mathematical modeling the effect of catalyst initial shape and the crack pattern in olefin copolymerization
121
133
EN
Marzieh
Nouri
Iran Polymer and Petrochemical Institute (IPPI), P. O. Box 14975/112, Tehran, Iran
marzieh_nouri1@yahoo.com
Mahmoud
Parvazinia
Iran Polymer and Petrochemical Institute (IPPI), P. O. Box 14975/112, Tehran, Iran
m.parvazinia@ippi.ac.ir
Hassan
Arabi
Iran Polymer and Petrochemical Institute (IPPI), P. O. Box 14975/112, Tehran, Iran
h.arabi@ippi.ac.ir
Mohsen
Najafi
Qom University of Technology, P. O. Box 1519-37195, Qom, Iran
najafi.m@qut.ac.ir
10.22063/poj.2015.1165
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.
single particle,modelling,finite element method,polyolefin,copolymerization
http://poj.ippi.ac.ir/article_1165.html
http://poj.ippi.ac.ir/article_1165_b2df56b622f083cfcc23024846130f45.pdf