Synthesis of high molecular weight isobutylene-α-methylstyrene copolymers containing alkenyl groups with a half sandwich scandium initiator system under mild conditions

2019 ◽  
Vol 10 (14) ◽  
pp. 1724-1729 ◽  
Author(s):  
Ke Yang ◽  
Hui Niu ◽  
Hui Yu ◽  
Jinghan Dong ◽  
Jing Wang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Random Copolymers ◽  
Mild Conditions ◽  
Initiator System ◽  
Half Sandwich

Copolymerizations of isobutylene and two alkenyl functionalized α-MeSt derivatives respectively, catalyzed by [(C5Me4SiMe3)Sc(CH2SiMe3)2THF], at −35 °C produced high Mn random copolymers with pendant alkenyl groups.

Cationic half-sandwich scandium complex for the synthesis of polyisobutylene with high molecular weight under mild conditions

2017 ◽  
Vol 56 (5) ◽  
pp. 467-470 ◽  
Author(s):  
Ke Yang ◽  
Tingting Li ◽  
Rui Tan ◽  
Kaihua Shen ◽  
Yang Li
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Mild Conditions ◽  
Half Sandwich

Synthesis, Characterization, and Properties of High Molecular Weight Poly(ferrocenylgermanes) and Poly(ferrocenylsilane)−Poly(ferrocenylgermane) Random Copolymers

1996 ◽  
Vol 29 (7) ◽  
pp. 2396-2403 ◽  
Author(s):  
Timothy J. Peckham ◽  
Jason A. Massey ◽  
Mark Edwards ◽  
Ian Manners ◽  
Daniel A. Foucher
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Random Copolymers ◽  
High Molecular Weight Poly

Efficient Synthesis of Well-Defined, High Molecular Weight, and Processible Polyanilines under Mild Conditions via Palladium-Catalyzed Amination

2000 ◽  
Vol 122 (31) ◽  
pp. 7606-7607 ◽  
Author(s):  
Xiao-Xiang Zhang ◽  
Joseph P. Sadighi ◽  
Thomas W. Mackewitz ◽  
Stephen L. Buchwald
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Efficient Synthesis ◽  
Mild Conditions ◽  
Palladium Catalyzed

Cationic copolymerization of indene with styrene derivatives: Synthesis of random copolymers of indene with high molecular weight

2002 ◽  
Vol 40 (14) ◽  
pp. 2449-2457 ◽  
Author(s):  
Shokyoku Kanaoka ◽  
Nobuyuki Ikeda ◽  
Akira Tanaka ◽  
Hitoshi Yamaoka ◽  
Toshinobu Higashimura
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Random Copolymers ◽  
Cationic Copolymerization ◽  
Styrene Derivatives

Large ultra-high molecular weight polyethylene spherical particles produced by AlR3 activated half-sandwich chromium(iii) catalysts

2011 ◽  
Vol 40 (39) ◽  
pp. 10184 ◽  
Author(s):  
Mingtai Sun ◽  
Tieqi Xu ◽  
Wei Gao ◽  
Yang Liu ◽  
Qiaolin Wu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Spherical Particles ◽  
Ultra High Molecular Weight ◽  
Half Sandwich

Synthesis and characterization of high molecular weight and low dispersity polystyrene homopolymers by RAFT polymerization

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Cheng Jin ◽  
Chun Liu ◽  
Bo Jiang ◽  
Qin-jian in
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Polymerization Temperature ◽  
Polymer Molecular Weight ◽  
Mild Conditions ◽  
Reversible Addition ◽  
Polymerization Method

AbstractHigh molecular weight polystyrene homopolymers with low dispersity were synthesized by a reversible addition-fragmentation chain transfer (RAFT) polymerization method using 0.03 and 0.3 wt% of cumyl dithiobenzoate (CDB) vs. styrene (St) and the azobis(isobutyronitrile) initiator, at the polymerization temperature of 60 or 70 °C. The optimal high molecular weight polystyrene via this synthetic scheme shows Mw = 46.5×104, Mn = 33.3×104, and a dispersity of 1.40. The polystyrene chain contains a dithiobenzoate C=S moiety and thus can be used as a macro-chain-transfer agent for the polymerization of other monomers and for the synthesis of diversified block copolymers under mild conditions. The changes of the polystyrene molecular weight and dispersity were studied by the influences of the initial concentration ratio of CDB to styrene ([CDB]0/[St]0), the polymerization temperature, and the polymerization time. The PS molecular weight is inversely proportional to the [CDB]0/[St]0 ratio. Decreasing CDB from 0.3 to 0.03 wt%, a high MW PS was obtained, while the dispersity was observed to increase from 1.10 to 1.40. The PS molecular weight increases with the increase of the reaction time, while the dispersity of PS varies little from 1.12 to 1.23. The molecular weight and dispersity increase with the increase of the polymerization temperature. As the temperature arises from 60°C to 70°C, the conversion increases considerably from 25.8% to 39.9%, and the dispersity increases slightly from 1.15 to 1.17. As the temperature reaches 80°C, the conversion increases considerably to 64.7%, and the dispersity increases to 1.53. The polymer molecular weight of the polystyrene prepared by the RAFT method is suitable for the applications of engineering materials.

scholarly journals AlCl3×OPh2-Co-initiated cationic polymerization of anethole: facile access to high molecular weight polymers under mild conditions

2022 ◽  
pp. 110983
Author(s):  
Maksim I. Hulnik ◽  
Olga V. Kuharenko ◽  
Peter Timashev ◽  
Irina V. Vasilenko ◽  
Sergei V. Kostjuk
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Cationic Polymerization ◽  
Mild Conditions ◽  
High Molecular Weight Polymers

Synthesis of high molecular weight polyisobutylene with Al(C6F5)3-based initiating systems under mild conditions

Polymer ◽  
2022 ◽  
pp. 124539
Author(s):  
Ling Cai ◽  
Bo Liu ◽  
Xinli Liu ◽  
Dongmei Cui
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Mild Conditions ◽  
High Molecular Weight Polyisobutylene

scholarly journals NEW AROMATIC DINITRODERIVATIVES OF CHLORAL AS MONOMER FOR SYNTHESYS OF POLYESTER AND POLYHETERO-ARYLENE

2018 ◽  
Vol 61 (2) ◽  
pp. 4
Author(s):  
Ruslan M. Kumykov ◽  
Arsen K. Vologirov
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Strength Properties ◽  
High Reactivity ◽  
Activation Mechanism ◽  
Aromatic Diamines ◽  
Synthesis Conditions ◽  
Mild Conditions ◽  
Methods Of Synthesis ◽  
Methylene Groups

The synthesis of aromatic dinitroderivatives of chloral effectively used in production of soluble, heat and fire resistant polyester and polyhetero arylenes using in the reaction of aromatic nucleophilic replacement was studied. The groups of new aromatic dinitroderivatives containing chloral as central groups between the phenyl nuclei: dichlorethelyne, carbonyl, acetylene and methylene groups were considered. The synthesis conditions were improved for polyester polyesterketones, polyesteretherketones, poliftalimides and polynaphtalamids without substantially affecting the thermal and solid characteristics achieved under relatively mild conditions using nucleophilic polynitro substitution. The search of new functional groups used in the condensation reactions, is an urgent task of polymer chemistry. Such groups must be determined by enough high reactivity of the monomers, without reducing their availability and without increasing their toxicity. It has decisive importance in the structure of initial monomers, which would be determined by the properties of polymers and the solubility of the target. In this aspect, dinitro compounds containing diphenyl, phthalimide and naftalimidnye cycles are presented their unique structures. It is known that improvement in meltability and solubility of the polymers without significant effect on the thermal and strength properties achieved by the introduction of these "carded" groups bulky substituents or phenyl phenoxide, flexible "bridge" fragments and introduced into the aromatic nuclei of the starting compounds bulk chlorine atoms. As part of this review it was made an attempt to describe methods of synthesis and properties of aromatic dinitropro- derivatives containing combinations of bulky substituents and flexible "bridged" groups using as initial compounds the simplest derivatives of chloral. The mostly known polyimides and polyetherimides prepared by reacting dianhydrides of aromatic tetracarboxylic acids with aromatic diamines with two-staged process where the first stage, a poly (o-carboxy) imides, and the second, due to thermal or catalytic imidization of polyamides with low solubility in organic solvents. It should be noted that the second stage -thermal or catalytic imidization not always results in a totally cycling polyamides that reduces the possibility of a relatively high molecular weight of polymers. At using aromatic dinitro- compounds containing a phthalimide and naftalimide cycles as comonomers bis-phenols, the problem of the extent of cyclization is absent. It was noted that an important determinant of obtaining high molecular weight of polymers is using nucleophilic polinitro-substitution in a process flow on the first stage under relatively mild conditions in a medium of DMSO or DMSO / toluene at 70 °C for 2 h in a completely dry environment. The review deals with some aspects of activation mechanism of nitro groups in nucleophilic polynitro-substitution. The processes of synthesis of condensation monomers of dinitro-derivatives using chloral were considered in detail. The methods of preparation and some properties of aromatic dinitroarilene, dinitroftalimide and dinitronaftalimide with dichlorethylenes, ketones, acetylene and methylene "bridged" groups between the phenyl nuclei are given. Forcitation:Kumykov R.M., Vologirov A.K. New aromatic dinitroderivatives of chloral as monomer for synthesys of polyester and polyhetero- arylene. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 2. P. 4-14

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