Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
10
2
2023
05
01
Development of half-titanocene catalysts for synthesis of cyclic olefin copolymers
59
70
EN
Kotohiro
Nomura
Department of Chemistry, Tokyo Metropolitan University, Hachioji, Tokyo, 1920397, Japan
ktnomura@tmu.ac.jp
10.22063/poj.2023.3308.1250
Certain cyclic olefin copolymers (COCs) are known as promising amorphous materials with high transparency in the UV-vis region, thermal and humidity resistance, low dielectric constant, low water absorption, and dimensional stability. This short review focuses on the synthesis of (new) cyclic olefin copolymers by designed (nonbridged) half-titanocene catalysts, which enabled to proceed synthesis of the amorphous polymers by ethylene/ propylene copolymerization not only with norbornene (NBE), and tetracyclododecene (TCD), but also with so called low strained cyclic olefins (cyclopentene, cyclohexene, cycloheptene, and cyclooctene). Their thermal properties (glass transition temperature, T<sub>g </sub>values) are affected by structure of the cyclic olefin employed and the contents, whereas linear relationships between T<sub>g</sub> values and the contents were observed in all cases.
Cyclic olefin copolymers,titanium catalyst,half-titanocene,norbornene,cyclic olefin
http://poj.ippi.ac.ir/article_1935.html
http://poj.ippi.ac.ir/article_1935_f346186cb61bfd78239e149a9e5ce592.pdf
Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
10
2
2023
05
01
Copolymerization of ethylene with norbornene by using metallocene/TIBA/B(C6F5)3 system
71
77
EN
Wei
Wang
SINOPEC (Beijing) Research Institute of Chemical Industry Co., Ltd., No. 14 Beisanhuan Donglu, Chao Yang District, Beijing (100013), China
wangw.bjhy@sinopec.com
Shuzhang
Qu
SINOPEC (Beijing) Research Institute of Chemical Industry Co., Ltd., No. 14 Beisanhuan Donglu, Chao Yang District, Beijing (100013), China
qushzh.bjhy@sinopec.com
Xinwei
Li
SINOPEC (Beijing) Research Institute of Chemical Industry Co., Ltd., No. 14 Beisanhuan Donglu, Chao Yang District, Beijing (100013), China
lixw.bjhy@sinopec.com
Jian
Chen
SINOPEC (Beijing) Research Institute of Chemical Industry Co., Ltd., No. 14 Beisanhuan Donglu, Chao Yang District, Beijing (100013), China
chenjian.bjhy@sinopec.com
Xiaolei
Wang
SINOPEC (Beijing) Research Institute of Chemical Industry Co., Ltd., No. 14 Beisanhuan Donglu, Chao Yang District, Beijing (100013), China
wangxl.bjhy@sinopec.com
Cui
Zheng
SINOPEC (Beijing) Research Institute of Chemical Industry Co., Ltd., No. 14 Beisanhuan Donglu, Chao Yang District, Beijing (100013), China
zhengc.bjhy@sinopec.com
Min
Guo
SINOPEC (Beijing) Research Institute of Chemical Industry Co., Ltd., No. 14 Beisanhuan Donglu, Chao Yang District, Beijing (100013), China
guom.bjhy@sinopec.com
Ying
Wang
SINOPEC (Beijing) Research Institute of Chemical Industry Co., Ltd., No. 14 Beisanhuan Donglu, Chao Yang District, Beijing (100013), China
wangy0116.bjhy@sinopec.com
10.22063/poj.2022.3289.1245
Cyclic olefin copolymer is a type of high-performance polyolefin material, which is prepared by using a single-site catalyst in solution polymerization. The common activator of this system is alkyl aluminoxane or organic boron/aluminum system. Among them, organic boron is mostly triphenylcarbenium tetrakis(pentafluorophenyl)borate or dimethylanilinium tetrakis(pentafluorophenyl)borate. In this study, ethylene and norbornene were copolymerized with metallocene catalyst activated with the combination of tris(pentafluorophenyl)boron and triisobutylaluminium. Compared with homopolymerization of ethylene, copolymerization shows high activity. The molecular weight of the polymer increased significantly with the increase of the insertion rate of norbornene. Fineman-Ross method was used to calculate the reactivity ratio, which showed that the reactivity ratio of norbornene was much lower than that of ethylene. The high copolymerization activity may indicate that, although norbornene has a lower coordination probability, its insertion rate is higher than ethylene. The copolymer with higher norbornene incorporation has a higher glass transition temperature, and the relationship between them is linear.<br />
Cyclic olefin copolymer,metallocene,norbornene,organic borate,glass transition temperature
http://poj.ippi.ac.ir/article_1931.html
http://poj.ippi.ac.ir/article_1931_27bf516a36386f728a245b246104352e.pdf
Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
10
2
2023
05
01
Polymerization of methyl methacrylate using bis(imine)cobalt, a polyolefin catalyst
79
88
EN
Majedeh
Maroofi
Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, P.O. Box 91775, Mashhad, Iran
majedehmaroofi@gmail.com
Gholam
Hossein
Zohuri
0000-0003-2380-8363
Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, P.O. Box 91775, Mashhad, Iran
zohuri@um.ac.ir
Saeid
Ahmadjo
0000-0002-8536-115X
Department of Engineering, Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran
s.ahmadjo@ippi.ac.ir
Navid
Ramezanian
0000-0003-3266-4277
Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, P.O. Box 91775, Mashhad, Iran
ramezanian@um.ac.ir
10.22063/poj.2023.3341.1257
A mono-nuclear catalyst of bis-imine cobalt (MC) was synthesized with using 2,6-dibenzhydryl-4-ethoxy phenyl as a ligand. The so huge ligand was prepared via the reaction of 2,6-dibenzhydryl-4-ethoxy phenyl)-N=(CH<sub>3</sub>)-C(CH<sub>3</sub>)=O with diacetyl with equal mole stoichiometry in presence of formic acid catalysis. The catalyst was synthesized via a reaction between the ligands and cobalt salt (CoCl<sub>2</sub>). The catalyst was used for polymerization of methyl methacrylate (MMA), (a polar monomer) in the presence of modified methylaluminoxane (MMAO). The highest polymerization activity (8.6 g PMMA/mmol cat. h) was obtained at [cocatalyst]/[catalyst]=1000:1 molar ratio and at room temperature reaction. For the prepared PMMA, Polymer with branching density of 263/1000C was obtained using <sup>1</sup>H NMR technique calculation. The microstructure of one of the produced PMMA was as follow: 48% syndiotactic, 29% isotactic and 23% atactic. GPC analysis of the polymer showed a number average molecular weight of about 5.7 × 10<sup>5</sup> g/mol and a narrow molecular weight distribution of 1.57.
Bis-imine cobalt catalysis,polymethyl methacrylate,polymerization,tacticity
http://poj.ippi.ac.ir/article_1943.html
http://poj.ippi.ac.ir/article_1943_1e4ff750822ec36167f0338ee25ccf17.pdf
Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
10
2
2023
05
01
Advances in PNP-ligated rare-earth-metal complexes: Reactivity and catalytic performances
89
99
EN
Hongfan
Hu
Petrochina Petrochemical Research Institute, Petrochina Company Limited, Beijing 102206, China
huhongfan@petrochina.com.cn
Rongqing
Ma
Provincial Key Laboratory of Polyolefin New Materials, College of Chemistry & Chemical Engineering, the Northeast Petroleum University, Daqing 163318, China
1324025520@qq.com
Chenxi
Cui
Petrochina Petrochemical Research Institute, Petrochina Company Limited, Beijing 102206, China
cuichenxi@petrochina.com.cn
Guoliang
Mao
Provincial Key Laboratory of Polyolefin New Materials, College of Chemistry & Chemical Engineering, the Northeast Petroleum University, Daqing 163318, China
maoguoliang@nepu.edu.cn
Shixuan
Xin
Petrochina Petrochemical Research Institute, Petrochina Company Limited, Beijing 102206, China
brucesxin@hotmail.com
10.22063/poj.2023.3349.1259
Due to the large ionic radius and high electro-positivity nature, rare earth metal complexes are difficult to stabilize and undergo pathways like ligand redistribution and intramolecular C-H activation. To solve such problems and retain reactive versatility, rare earth complexes supported by a variety of tridentate PNP pincer ligands have been explored. Such complexes can serve as perfect precursors for preparing ultra-active rare earth species containing two metal-carbon bands, let alone Ln=N and Ln=P multiple bonds. In addition, the combined stability and activity of the cation rare earth mediates made them the best catalysts for the polymerization of olefins and other non-polar hydrocarbon monomers, especially conjugated dienes. The practical utilization of rare earth metal catalysts for new materials production have also extensively explored by experts from the academic and industries.
PNP ligand,rare earth metals,Lanthanides,Reactivity,catalysis
http://poj.ippi.ac.ir/article_1947.html
http://poj.ippi.ac.ir/article_1947_fdde28ad13e047c18a464e70d6696b1c.pdf
Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
10
2
2023
05
01
Exploring the possibility of chemisorption of ethylene on graphene with and without defects
101
115
EN
Parisa
Alamdari
Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran, Iran
p.alamdari@aut.ac.ir
Farhad
Sharif
0000-0002-0801-1076
Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran, Iran
sharif@aut.ac.ir
Saeedeh
Mazinani
New Technologies Research Center (NTRC), Amirkabir University of Technology, Tehran, Iran
s.mazinani@aut.ac.ir
10.22063/poj.2023.3316.1254
The effect of structural defects on graphene interaction with other molecules is of high interest. In this study, the interaction of ethylene molecules with pristine graphene (PG) and defective graphenes including single (SVG) and double (DVG) vacancies, were investigated using dispersion-corrected periodic density functional theory (DFT). We used various pairs of pseudopotentials and dispersion-corrected methods to calculate the exchange-correlation energies and long-range energies, respectively. We conducted the calculations in the ethylene-graphene equilibrium distance where vdW interaction as a long-range interaction was dominant. Both adsorption and deformation energies were calculated to examine the possibility of ethylene chemisorption. It was found that there is a critical distance from the graphene surface, where the nature of adsorption of adsorbate molecule changes from physisorption to the possible chemisorption depending on the energetical costly distortion induced in adsorbate molecule. In the case of ethylene adsorption on the graphene structures studied here, the mentioned critical distances follow the order SVG < DVG < PG. However, in the range of vdW domination and in comparison with PG, ethylene interacts more with SVG due to the presence of a dangling bond and interacts less with DVG due to the presence of a hole. Furthermore, the interactions of ethylene with reconstructed trivacancy were studied. Moreover, all possible orientations for ethylene adsorption on graphene structures were considered and energetically compared. All calculations were done on fully optimized reconstructed geometries of vacancies with structural characteristics, i.e., reconstruction length and formation energies comparable to those reported in the literature.
Carbon dimer,carbon vacancy,DFT,adsorption,active site
http://poj.ippi.ac.ir/article_1949.html
http://poj.ippi.ac.ir/article_1949_1019d6d12cfb80be0c8e621849417bd4.pdf
Iran Polymer and Petrochemical Institute
Polyolefins Journal
2322-2212
2345-6868
10
2
2023
05
01
Effects of the nozzle arrangement and aerator configuration in slug bubble production to enhance the foulant removal from a flat sheet membrane bioreactor
117
126
EN
Nazila
Sutudehnezhad
Department of Chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
nazila.sutudehnezhad@gmail.com
Amir
Heydarinasab
Department of Chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
a.heidarinasab@srbiau.ac.ir
Reza
Yegani
Faculty of Chemical Engineering, Sahand University of Technology, Tabriz, Iran
ryegani@sut.ac.ir
Farshid
Pajoum Shariati
Department of Chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
pajoum@srbiau.ac.ir
10.22063/poj.2023.3364.1260
Membrane bioreactors (MBRs) are high-tech systems for water recycling and reusing of unconventional water resources such as municipal wastewater. However, the fouling of polymeric membranes is the main impediment to the market development of MBR. The polyolefin-based membranes are subjected to more severe organic fouling than other hydrophilic membranes due to their inherent strong hydrophobic properties, therefore, proposing efficient, fast, and economic fouling mitigation methods is vital for durable and long-standing performance. In this research, the hydrodynamics of a lab-scale membrane bioreactor with different configurations of aerators and nozzle sizes were used to investigate the air scouring efficiency. It was gained that aerators with higher air flow rates, e.g., 5.5 m/s can produce slug bubbles which are capable of foulant removal from the membrane surface. In comparison with a non-central aerator, the satisfactory scouring zone of the central aerator is narrow and the edge nozzles on both sides of the aerator are blocked. Under constant air flow rate, when the inlet air is injected into the aerator from two and three points, not only the end nozzles are blocked but also the liquid is penetrated into the aerator and the shear stress on the membrane surface decreased to 0.765 Pa. In the case of the non-central aerator, the satisfactory scouring zone becomes wider and neither nozzle blockage nor liquid penetration down to the aerator has occurred. The distribution of bubbles was optically evaluated by video imaging through the transparent plexiglass tank using aerators with different inlet flow rates and various configurations. Numerical simulations and related experimental analyses demonstrated that air inlet velocity has an important role in creating larger slug bubbles. It was shown that a non-central aerator in which the central nozzle in front of the inlet air stream is blocked, produces slug bubbles and sufficient air scoring on the flat sheet membrane. Configuration of a non-central aerator with 4 nozzles not only increased the satisfactory zone of each aerator without blockage of edge nozzles and liquid penetration into the aerator but also provided a higher shear rate over 1.104 Pa under a constant flow rate, which consequently removed the foulant from the membrane surface.
Computational Fluid Dynamics,Aerator,Shear Stress,Satisfactory Area,Nozzle Arrangement
http://poj.ippi.ac.ir/article_1951.html
http://poj.ippi.ac.ir/article_1951_cbc88170222b1ff51447c0df655d7cbc.pdf