Search results for "Chain transfer"
showing 10 items of 85 documents
Control over Branching Topology by Introducing a Dual Catalytic System in Coordinative Chain Transfer Polymerization of Olefins
2020
Coordinative polymerization brings opportunities for producing well-defined long-chain branched polyolefins specifically by using homogeneous single-site catalysts. Herein, we report a new dual cat...
Hollow Polymeric Capsules from POSS-Based Block Copolymer for Photodynamic Therapy
2016
A novel amphiphilic diblock copolymer, PHEMAPOSS-b-P(DMAEMA-co-CMA), was prepared via reversible addition–fragmentation chain transfer (RAFT) polymerization, where PHEMAPOSS block was first synthesized using a methacrylate monomer based on polyhedral oligomeric silsesquioxane (HEMAPOSS), and PHEMAPOSS was further utilized to prepare the block copolymer via RAFT copolymerization of 2-(dimethylamino)ethyl methacrylate (DMAEMA) and reduction-cleavable coumarin methacrylate (CMA) monomer. PHEMAPOSS-b-P(DMAEMA-co-CMA) could self-assemble in water to form spherical micelles with POSS core and stimuli-responsive shell. The micelles were cross-linked by photodimerization of coumarin, and then hollo…
RAFT Polymerization of Pentafluorophenyl Methacrylate: Preparation of Reactive Linear Diblock Copolymers
2005
Reversible addition fragmentation chain transfer (RAFT) polymerization of pentafluorophenyl methacrylate (PFMA) was carried out in the presence of cumyldithiobenzoate and 4-cyano-4-((thiobenzoyl)sulfanyl)pentanoic acid, respectively. These chain transfer agents with 2,2'-azoisobutyronitrile (AIBN) as initiator yielded the active ester polymer poly(PFMA) with M n up to 17000 g . mol -1 and low polydispersity index (M w /M n <1.2). Kinetic analysis using 19 F NMR spectroscopy and gel permeation chromatography (GPC) measurements showed controlled polymerization behavior for both chain transfer agents. Successful preparation of linear diblock copolymers consisting of an active ester block and m…
1993
Star-Like Polymers of tert -Butyl Acrylate via Controlled Radical Polymerization - Synthesis and Properties
2011
Summary: Star polymers with different numbers and lengths of poly(tert-butyl acrylate) arms were obtained by the core-first method via atom transfer and iodine mediated radical polymerization. Multifunctional initiators with different numbers of initiating groups (from 3 to 28) were used to initiate the polymerization of tert-butyl acrylate, yielding stars with different numbers of arms. The structures of the stars were characterized by NMR and gel permeation chromatography with refractive index, multiangle laser light scattering and viscosimetric detectors.
Tailored Semiconducting Polymers: Living Radical Polymerization and NLO-Functionalization of Triphenylamines
2002
This paper describes the preparation of various polymers with triarylamine side groups. High molecular weight materials were obtained by free radical polymerization utilizing the gel effect. Polymers with a marrow polydispersity and a predetermined molecular weight could be prepared by living radical polymerization. The T g could, thereby, be controlled between 50 and 140°C either by using different monomers or by varying the molecular weight. Living radical polymerization allowed in addition the preparation of block copolymers. The triarylamine side groups could be transformed into NLO-chromophores by reaction with tetracyanoethylene. This leads to the incorporation of tricyanoethylene. Th…
Cyclodextrins in Polymer Synthesis: Free-Radical Polymerization of Methylated β-Cyclodextrin Complexes of Methyl Methacrylate and Styrene Controlled…
2000
Polymerization of an activated ester monomer based on 4-vinylsulfonic acid and its polymer analogous reaction
2011
Homopolymers containing sulfonic ester side groups were synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization utilizing benzyl dithiobenzoate, cumyl dithiobenzoate, and 4-cyano-4-((thiobenzoyl)sulfanyl)pentanoic acid as chain transfer agents. Likewise diblock copolymers containing poly(styrene), poly(octylstyrene) and poly(pentafluorostyrene) as the second block were synthesized. Additionally, nitroxide mediated polymerization (NMP) was investigated for the synthesis of a homopolymer as well as for a diblock copolymer. Furthermore, the post-polymerization functionalization with various amines to yield the respective sulfonamides was conducted. The conversion …