Producing bimodal molecular weight distribution polymers through facile one-pot/one-step RAFT polymerization

2012 ◽  
Vol 50 (19) ◽  
pp. 4103-4109 ◽  
Author(s):  
Hongjuan Jiang ◽  
Lifen Zhang ◽  
Jian Qin ◽  
Wei Zhang ◽  
Zhenping Cheng ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Raft Polymerization ◽  
One Pot ◽  
One Step

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.

scholarly journals Synthesis of Well-Defined Alternating Copolymer Composed of Ethylmaleimide and Hydroxy-Functionalized Vinyl Ether by RAFT Polymerization and Their Thermoresponsive Properties

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2255
Author(s):  
Jin Motoyanagi ◽  
Ayaha Oguri ◽  
Masahiko Minoda
Keyword(s):  
Molecular Weight ◽  
Vinyl Ether ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Cold Water ◽  
Raft Polymerization ◽  
Polymer Concentration ◽  
Incident Wavelength ◽  
Alternating Copolymer ◽  
Copolymer Poly

Here we report the controlled synthesis of alternating copolymers by reversible addition-fragmentation chain transfer (RAFT) polymerization of hydroxy-functionalized vinyl ether (DEGV) and ethylmaleimide (EtMI) using dithiocarbonate derivative (CPDB) as the RAFT reagent. The resulting alternating copolymer poly[ethylmaleimide-alt-(diethylene glycol mono vinyl ether)] (poly(MalMI-alt-DEGV)) had a relatively narrow molecular weight distribution (Mw/Mn < 1.4). These polymers are fully soluble in cold water (5 °C) and an aqueous solution of poly(MalMI-alt-DEGV) became turbid upon heating (using an incident wavelength of 600 nm and 1.0 mg mL−1 (0.1 wt %) polymer concentration), indicating phase separation above the cloud point temperature (Tcp). The Tcp of the polymer solution ranged from 15–35 °C, depending on the molecular weight and molecular weight distribution of the polymer.

Controlled Bimodal Molecular-Weight-Distribution Polymers: Facile Synthesis by RAFT Polymerization

2012 ◽  
Vol 18 (19) ◽  
pp. 6015-6021 ◽  
Author(s):  
Jian Qin ◽  
Lifen Zhang ◽  
Hongjuan Jiang ◽  
Jian Zhu ◽  
Zhengbiao Zhang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Raft Polymerization ◽  
Facile Synthesis

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...

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