Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
1
1
2014
01
01
Macromolecular non-releasing additives for safer food packaging: application to ethylene/α-olefins and propylene based polymers
1
15
EN
Maria Carmela
Sacchi
Istituto per lo Studio delle Macromolecole (ISMAC-CNR), via E. Bassini 15, 20133 Milano (Italy)
sacchi@ismac.cnr.it
Simona
Losio
Istituto per lo Studio delle Macromolecole (ISMAC-CNR), via E. Bassini 15, 20133 Milano (Italy)
s.losio@ismac.cnr.it
Paola
Stagnaro
Istituto per lo Studio delle Macromolecole (ISMAC-CNR), via De Marini 6, 16149 Genova (Italy)
stagnaro@ge.ismac.cnr.it
Giorgio
Mancini
Istituto per lo Studio delle Macromolecole (ISMAC-CNR), via De Marini 6, 16149 Genova (Italy)
mancini@ge.ismac.cnr.it
Luca
Boragno
Istituto per lo Studio delle Macromolecole (ISMAC-CNR), via De Marini 6, 16149 Genova (Italy)
boragno@ge.ismac.cnr.it
Stefano
Menichetti
Dipartimento di Chimica ‘Ugo Schiff’, Università di Firenze, via della Lastruccia 13, 50019 Sesto Fiorentino (FI) (Italy)
stefano.menichetti@unifi.it
Caterina
Viglianisi
Dipartimento di Chimica ‘Ugo Schiff’, Università di Firenze, via della Lastruccia 13, 50019 Sesto Fiorentino (FI) (Italy)
caterina.viglianisi@unifi.it
Sara
Limbo
Department of Food, Environmental and Nutritional Sciences DeFENS, University of Milan, Via Celoria 2, 20133, Milano (Italy)
sara.limbo@unimi.it
10.22063/poj.2014.888
Some innovative solutions are proposed to the problem of the unavoidable physical migration of antioxidants from plastic films for packaging, in order to minimize the consequent undesirable effect of food contamination. In previous exploratory tests, phenolic antioxidant co-units were achieved and incorporated into polyethylene chain and now the work is extended to create new families of polymeric additives properly designed for specific material. An effective route was designed to synthesize the functionalized comonomer, analogues of commercial 2,6-<em>t</em>-butyl-4-methoxy-phenol (BHA), containing eight methylene units as spacer between the aromatic ring and the polymerizable olefinic double bond (C8). Ethylene/1-hexene/C8 terpolymers, with 1-hexene concentration in the typical range found in commercial polyethylene grades, and propylene/C8 copolymers with microstructure similar to those of commercial packaging polypropylenes were produced. A careful <sup>13</sup>C NMR study was conducted for the precise determination of the functionalized comonomer content on all terpolymer and copolymer samples. The samples melt blended with additive-free commercial LDPE and PP matrices, individually, were analyzed in terms of thermal and thermo-oxidative stability and compared with LDPE and PP films containing the traditional BHA additive analogue. The results demonstrate that, in either way, the polymeric additives exert a very positive effect on the degradation temperature of the polymeric matrices, retarding the thermo-oxidative sequence of reaction. <br />
macromolecular antioxidants,blends,Polyolefins,13C NMR,thermogravimetric analysis (TGA)
http://poj.ippi.ac.ir/article_888.html
http://poj.ippi.ac.ir/article_888_5e2430c42e2884c538d3ce4aee898a92.pdf
Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
1
1
2014
01
01
In situ stabilization of polypropylene by lignin using a Ziegler-Natta catalyst
17
24
EN
Maria
Marques
Instituto de Macromoléculas (IMA) - Universidade Federal do Rio de Janeiro - UFRJ, CP 68525, CEP 21941-
590, Rio de Janeiro-RJ, Brazil
fmarques@ima.ufrj.br
Renato
Oliveira
Instituto de Macromoléculas (IMA) - Universidade Federal do Rio de Janeiro - UFRJ, CP 68525, CEP 21941-
590, Rio de Janeiro-RJ, Brazil
rjbenne@ima.ufrj.br
Rafael
Araujo
Instituto de Macromoléculas (IMA) - Universidade Federal do Rio de Janeiro - UFRJ, CP 68525, CEP 21941-
590, Rio de Janeiro-RJ, Brazil
rafaelaraujo@ima.ufrj.br
Bruno
Amantes
Instituto de Macromoléculas (IMA) - Universidade Federal do Rio de Janeiro - UFRJ, CP 68525, CEP 21941-
590, Rio de Janeiro-RJ, Brazil
brunoamantes@ima.ufrj.br
10.22063/poj.2014.889
A fourth-generation Ziegler-Natta catalyst was prepared to synthesize polypropylene (PP), which was stabilized by in situpolymerization employing lignin as antioxidant. The antioxidant properties of lignin were compared with those of the commercial antioxidant Irganox 1010. The presence of lignin in the reaction medium slightly decreased the catalytic activity of the reaction. The isotacticity index (I.I.) of PP synthesized with lignin (PP-lig) was not affected by the presence of the additive in the reaction medium. The thermal properties, characterized by differential scanning calorimetry, showed slightly decreased degree of crystallinity (Xc), but the melting temperature (Tm) and crystallization temperature (Tc) were not affected when compared with the neat polymer. Lignin showed good activity as a stabilizer by thermogravimetry. The initial temperature of degradation (Tonset) increased when compared to the pure PP and PP stabilized with the commercial antioxidant. The lower carbonyl index of the PP, evaluated by infrared spectroscopy (FTIR) after thermo-oxidative treatment, also revealed the stabilizing action of lignin.
Antioxidant,Polypropylene,Ziegler-Natta catalyst
http://poj.ippi.ac.ir/article_889.html
http://poj.ippi.ac.ir/article_889_9c567a7ec51377f486629de4f20cd7d9.pdf
Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
1
1
2014
01
01
Synthesis of high molecular weight polyethylene using FI catalyst
25
32
EN
G.
Hossein
Zohuri
0000-0003-2380-8363
Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
zohuri@um.ac.ir
Saman
Damavandi
Department of Chemistry, Sarvestan Branch, Islamic Azad University, Fars, Iran
saman_damavandi@yahoo.com
Saeid
Ahmadjo
Department of Catalyst, Iran Polymer and Petrochemical Institute, Tehran, Iran
Reza
sandaroos
Department of Chemistry, Faculty of Science, University of Birjand, Birjand, Iran
r_sandaroos@yahoo.com
Mohammad
A.
Shamekhi
Department of Chemistry, Sarvestan Branch, Islamic Azad University, Fars, Iran
shamekhi2003@yahoo.com
10.22063/poj.2014.925
A FI Zr-based catalyst of <em>bis</em>[<em>N</em>-(3,5-dicumylsalicylidene)-2′,6′diisopropylanilinato]zirconium(IV) dichloride was prepared and used for polymerization of ethylene. The effects of reaction conditions on the polymerization were examined in detail. The increase in ethylene pressure and rise in polymerization temperature up to 35 <sup>o</sup>C were favorable for catalyst/MAO to raise the catalytic activity as well as the viscosity-average molecular weight (Mv) of polyethylene. The activity of the catalyst was linearly increased with increasing MAO concentration and no optimum activity was observed in the range studied. Although introduction of the bulky cumyl and 2′,6′-diisopropyl alkyl substitution groups on <em>ortho</em> positions to the phenoxy-oxygen and on phenyl ring on the <em>N</em>, respectively enhanced the viscosity average molecular weight (M<sub>v</sub>) of the obtained polymer strongly, diminished the activity of the catalyst. Neither the activity of the catalyst nor the (Mv) of the obtained polymer were sensitive to hydrogen concentration. However, higher amount of hydrogen could slightly increase the activity of the catalyst. The (Mv) of polyethylene ranged from 2.14×10<sup>6</sup> to 2.77×10<sup>6</sup> at the monomer pressure of 3 and 5 bar respectively which are much higher than that of the reported FI Zr-based catalysts.
FI Catalyst,high molecular weight,polyethylene,Ethylene polymerization
http://poj.ippi.ac.ir/article_925.html
http://poj.ippi.ac.ir/article_925_956e7a4385abf2c42f4b7b2881bd77be.pdf
Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
1
1
2014
01
01
Storage time effect on dynamic structure of MgCl2.nEtOH adducts in heterogeneous Ziegler-Natta catalysts
33
41
EN
Najmeh
Hadian
Department of Polymerization Engineering, Iran Polymer and Petrochemical Institute, P.O. Box 14965/115, Tehran, Iran.
m.hadian@ippi.ac.ir
Shokoofeh
Hakim
Department of Polymerization Engineering, Iran Polymer and Petrochemical Institute, P.O. Box 14965/115, Tehran, Iran.
s.hakim@ippi.ac.ir
Mehdi
Nekoomanesh-Haghighi
Department of Polymerization Engineering, Iran Polymer and Petrochemical Institute, P.O. Box 14965/115, Tehran, Iran.
m.nekoomanesh@ippi.ac.ir
Naeimeh
bahri-Laleh
0000-0002-0925-5363
Department of Polymerization Engineering, Iran Polymer and Petrochemical Institute, P.O. Box 14965/115, Tehran, Iran.
n.bahri@ippi.ac.ir
10.22063/poj.2014.904
Primary MgCl2.3.3EtOH adduct (PCT1) was prepared by melt quenching method and then submitted into a programmed thermal dealcoholation project using a fluidized bed reactor. During thermal dealcoholation program, different MgCl2.nEtOH support samples with n= 3.0, 2.7, 2.4, and 2.1 were selected and named as PCT2 to PCT5, respectively. Structural analysis of the support samples showed a significant increase in the surface area, from 7.4 m2/g to 12.8 m2/g, together with the decrease in peaks height at 2θ≈ 8.9 and 9.7˚ by moving from PCT1 to PCT5. After characterization of support samples, final catalysts were prepared by reacting these samples with TiCl4 and examined in slurry phase propylene polymerization. Prepared catalysts showed similar stereospecifities but different activities in the polymerization experiments, so that, with proceeding dealcoholation from PCT1 to PCT2 catalyst activity was reached a maximum amount of 2.9 kgPP/g Cat.h, and then by further dealcoholation, from PCT2 to PCT5, catalyst activity decreased gradually. In the last section, effect of time interval between thermal dealcoholation and catalyst preparation, which is called storage time, on the crystal and morphological characteristics of the two of the best adduct samples, namely MgCl2.2.4EtOH and MgCl2.3.0EtOH, was studied, as well. Storage time greatly affected the characteristics of the adducts together with resulted catalysts, and the best catalyst activity was achieved for the ones prepared immediately after adduct preparation.
Ziegler-Natta,MgCl2,thermal dealcoholation,polyolefin,dynamic structure
http://poj.ippi.ac.ir/article_904.html
http://poj.ippi.ac.ir/article_904_983c00eb6915c7c88018ee7236dd41db.pdf
Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
1
1
1999
11
30
Recent advances in the polymerization of butadiene over the last decade
43
60
EN
Giovanni
Ricci
CNR - Istituto per lo Studio delle Macromolecole (ISMAC), via E. Bassini 15, I-20133 Milano (Italy)
giovanni.ricci@ismac.cnr.it
Giuseppe
Leone
CNR - Istituto per lo Studio delle Macromolecole (ISMAC), via E. Bassini 15, I-20133 Milano (Italy)
giuseppe.leone@ismac.cnr.it
10.22063/poj.1999.890
The stereospecific polymerization of conjugated dienes began in 1954 with the first catalysts obtained by combining TiCl<sub>4</sub> or TiCl<sub>3</sub> with aluminum-alkyls, i.e. the catalytic systems previously employed for ethylene and propylene polymerizations. Subsequently, many other catalytic systems were obtained and examined by a combination of transition metal or lanthanide compounds with appropriate alkylating agents. With the advent of MAO as alkylating agent, at the beginning of the 1980s, new catalytic systems were introduced, in some cases much more active and stereospecific than those based on common aluminum-alkyls. Starting from the 2000s, in the wake of what happened in the case of mono-olefins, a new generation of catalysts based on complexes of transition ,metals and lanthanides with various ligands containing donor atoms such as P, N, O (e.g., phosphines, imines imino-pyridines, cheto-imines) has been introduced. These systems have proved particularly active and able to (provide polymers with controlled microstructure (i.e., cis-1,4; 1,2; mixed cis-1,4/1,2 with a variable 1,2 content ,from several types of 1,3-dienes, permitting indeed to establish new correlations between the catalyst structure the monomer structure and the polymer microstructure, and to improve our knowledge on the polymerization mechanism of 1,3-dienes. This paper provides an exhaustive overview of the latest developments in the field of stereospecific polymerization of 1,3-butadiene.
butadiene,catalysts,stereospecific polymerization,polybutadiene
http://poj.ippi.ac.ir/article_890.html
http://poj.ippi.ac.ir/article_890_e9bf950295ef1248df870af235efb76c.pdf
Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
1
1
2014
01
01
Propene-cycloolefin polymerization
61
75
EN
Laura
Boggioni
Instituto per lo Studio delle Macromolecole, Consiglio Nazionale delle Ricerche
Via E. Bassini 15, 20133 Milano, Italy
boggioni@ismac.cnr.it
Incoronata
Tritto
Instituto per lo Studio delle Macromolecole, Consiglio Nazionale delle Ricerche
Via E. Bassini 15, 20133 Milano, Italy
incoronata.tritto@scitec.cnr.it
10.22063/poj.2014.891
Highly active metallocenes and other single site catalysts have opened up the possibility of polymerizing cycloolefins such as norbornene (N) or of copolymerizing them with ethene (E) or propene (P). The polymers obtained show exciting structures and properties. E-N copolymers are industrially produced materials, with variable and high glass transitions depending on the wide range of their microstructures. By realizing the possibility in great variety of stereoregularity of propene and norbornene units and the difference in comonomer distribution, P-N copolymers were expected to have fine tuned microstructures and properties. Moreover, P-N copolymers should be characterized by higher T<sub>g</sub>-values than E-N copolymers with the same norbornene content and molar mass. A review of the state of the art of P-N copolymerization by <em>ansa</em>-metallocenes of C<sub>2</sub> symmetry, namely <em>rac</em>-Et(Ind)<sub>2</sub>ZrCl<sub>2 </sub>(I-I) and <em>rac</em>-Me<sub>2</sub>Si(Ind)<sub>2</sub>ZrCl<sub>2</sub> (I-II), and <em>rac</em>-Me<sub>2</sub>Si(2-Me-Ind)<sub>2</sub>ZrCl<sub>2</sub> (I-III), and of catalysts of C<sub>s</sub>symmetry, namely (<sup>t</sup>BuNSiMe<sub>2</sub>Flu)TiMe<sub>2</sub> (IV-I) and derivatives, is given here. Special emphasis is given to microstructural studies of P-N copolymers, including stereo- and regioregularity of propene units as well as of comonomer distribution, stereoregularity of norbornene units, and the structure of chain end-groups. This information allows us to find a rationale for the catalytic activities and the copolymer properties.
Propene,norbornene,metallocene catalysts,cycloolefin copolymers,microstructure
http://poj.ippi.ac.ir/article_891.html
http://poj.ippi.ac.ir/article_891_4d711f0e3d78c500e8f79498db80bdd9.pdf