Synthesis of high molecular weight and narrow molecular weight distribution poly(acrylonitrile) via RAFT polymerization

2012 ◽  
Vol 51 (5) ◽  
pp. 1197-1204 ◽  
Author(s):  
Shaogan Niu ◽  
Lifen Zhang ◽  
Jian Zhu ◽  
Wei Zhang ◽  
Zhenping Cheng ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Raft Polymerization ◽  
Narrow Molecular Weight Distribution ◽  
Poly Acrylonitrile

EFFECT OF REVERSIBLE ADDITION-FRAGMENTATION CHAIN TRANSFER EMULSION STYRENE–BUTADIENE RUBBER ON THE PROPERTIES OF SILICA COMPOUNDS

2020 ◽  
pp. 000-000 ◽  
Author(s):  
Hyunsung Mun ◽  
Kiwon Hwang ◽  
Gwanghoon Kwag ◽  
JaeKon Suh ◽  
Duseong Ahn ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Raft Polymerization ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Narrow Molecular Weight Distribution ◽  
Reversible Addition ◽  
Raft Agent ◽  
Styrene Butadiene

ABSTRACT In recent years, solution styrene–butadiene rubber (SSBR), which has a narrow molecular weight distribution, controllable microstructure, and chain end functionality, is mainly used as base rubber for passenger car tire tread compounds. However, SSBR has a lower molecular weight than that of emulsion SBR (ESBR) because it is difficult to increase the molecular weight of SSBR. In contrast, ESBR can easily increase the molecular weight; however, it has a broad molecular weight distribution. The reversible addition-fragmentation chain transfer (RAFT) polymerization technique is applicable to the emulsion polymerization. Polymers with narrow molecular weight distributions can be obtained by the RAFT polymerization because the RAFT agent prevents the coupling reaction of the growing chain radicals. In this case, ESBR having a narrow molecular weight distribution, which is an advantage of SSBR, and a high molecular weight, which is an advantage of ESBR, can be synthesized. Therefore, we synthesized RAFT ESBR and fabricated its compounds with silica filler. We confirmed that the physical properties of the RAFT ESBR silica compound are different from those of the ESBR silica compound. In addition to the narrow molecular weight distribution of the RAFT ESBR, the trithiocarbonyl group of the RAFT agent in the RAFT ESBR chain molecules affects the physical properties.

Bis(phenolate) N-heterocyclic carbene rare earth metal complexes: synthesis, characterization and applications in the polymerization of n-hexyl isocyanate

RSC Advances ◽  
2015 ◽  
Vol 5 (101) ◽  
pp. 83295-83303 ◽  
Author(s):  
Min Zhang ◽  
Jingjing Zhang ◽  
Xufeng Ni ◽  
Zhiquan Shen
Keyword(s):  
Molecular Weight ◽  
Rare Earth ◽  
Metal Complexes ◽  
High Molecular Weight ◽  
Molecular Weight Distribution ◽  
Rare Earth Metal ◽  
Weight Distribution ◽  
Earth Metal ◽  
Narrow Molecular Weight Distribution ◽  
Rare Earth Metal Complexes

Polyhexyl isocyanantes catalyzed by N-heterocyclic carbene rare earth metal complexes show high molecular weight with narrow molecular weight distribution.

Syndiospecific polymerization of styrene by half-titanocene catalysts with the sulfur-containing donor ligand

e-Polymers ◽  
2014 ◽  
Vol 14 (4) ◽  
pp. 277-281 ◽  
Author(s):  
Wei Wang ◽  
Gang Zheng ◽  
Hongtao Wang
Keyword(s):  
Molecular Weight ◽  
Catalytic Activity ◽  
High Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
High Catalytic Activity ◽  
Narrow Molecular Weight Distribution ◽  
Donor Ligand ◽  
High Yields ◽  
Sulfur Containing

AbstractMonocyclopentadienyl titanium complexes of the type Cp*TiX2 L (Cp*=C5 Me5, 1: L=C6 F5 S, X=OMe; 2: L=C6 F5 S, X=Cl; 3: L=2, 6-Me2-C6 H3 S, X=OMe) have been synthesized with high yields. These complexes are used as the catalysts for the syndiospecific polymerization of styrene. High catalytic activity is observed, and a polymer with high molecular weight and narrow molecular weight distribution is obtained. It is concluded that not only the sulfur-containing donor ligand but also the anion ligand strongly affects the polymerization activity and the molecular weight of the resultant polymer.

A unique cooperative catalytic system carrying metallic iron and 2-hydroxyethyl 2-bromoisobutyrate for the controlled/living ring-opening polymerization of ε-caprolactone

RSC Advances ◽  
2016 ◽  
Vol 6 (14) ◽  
pp. 11400-11406 ◽  
Author(s):  
Xiu-Juan Shang ◽  
Wen-Hua Zhang ◽  
Jian-Ping Lang
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Molecular Weight Distribution ◽  
Catalytic System ◽  
Weight Distribution ◽  
Metallic Iron ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Narrow Molecular Weight Distribution

Iron and 2-hydroxyethyl 2-bromoisobutyrate cooperatively initiates the ε-caprolactone polymerization, yielding polymers with high molecular weight and narrow molecular weight distribution.

Synthesis of thermo-sensitive polymer with super narrow molecular weight distribution: PET-RAFT polymerization of N-isopropyl acrylamide meditated by cross-linked zinc porphyrins with high active site loadings

2021 ◽  
Author(s):  
Fanfan Li ◽  
Yi Yu ◽  
Hanyu Lv ◽  
Guiting Cai ◽  
Yanwu Zhang
Keyword(s):  
Molecular Weight ◽  
Heterogeneous Catalysis ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Active Site ◽  
Raft Polymerization ◽  
Cross Linking ◽  
Narrow Molecular Weight Distribution ◽  
Isopropyl Acrylamide ◽  
Zinc Porphyrins

To overcome aggregation of porphyrins and realize heterogeneous catalysis with high active site loadings, the twisted ZnTHP-Me2Si and layered ZnTHP-Ph2Si are synthesized through cross-linking zinc tetraphenylporphyrin (ZnTHP) respectively with dichlorodimethylsilane...

Peculiarities of flow and viscoelastic properties of solutions of polymers with a narrow molecular-weight distribution

1973 ◽  
Vol 9 (11) ◽  
pp. 1231-1249 ◽  
Author(s):  
G.V. Vinogradov ◽  
A.Ya. Malkin ◽  
N.K. Blinova ◽  
S.I. Sergeyenkov ◽  
M.P. Zabugina ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Viscoelastic Properties ◽  
Narrow Molecular Weight Distribution
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