Macromol. Chem. Phys. 20/2016

Abstract

Front Cover: This work represents the RAFT copolymerization of the phosphine‐functional styrenic monomer, 4‐(diphenylphosphino)styrene, with styrene. Copolymerization behaviour is explored to establish the statistical distribution of the phosphine functionality within the copolymer. There is a strong tendency for the phosphine‐bearing monomer to homopolymerize whilst styrene prefers to copolymerize. This results in the polymer possessing gradient‐microstructure from preferential incorporation of phosphine‐based functionality. Further details can be found in the article by Kyle J. Sykes, Simon Harrisson, and Daniel J. Keddie* on page 2310.

Asymmetric Copolymers: Synthesis, Properties, and Applications of Gradient and Other Partially Segregated Copolymers

“…Several groups have attempted to improve the representation and classification of gradient copolymers. One approach is to display a number of simulated chains, with the probability of finding a monomer at each location determined by the monomer composition at the conversion corresponding to that location and the identity of the previous added monomer ( Figure ) . This provides information on the interchain variation as well as the distribution of alternating sequences and blocks within each chain, but still conflates conversion with chain length and is difficult to quantify numerically.…”

“…The lower representation shows the discrete nature of the polymer chains, typical block lengths, and the expected variation in composition between chains, but ignores the polymer length distribution and conflates conversion with chain length. Figure based on data from Sykes et al…”

“…Many techniques have been used for the preparation of asymmetric copolymers, including anionic and cationic polymerizations, C1 polymerization, catalyst transfer polycondensation, catalyzed copolymerization of olefins and epoxides, ring‐opening metathesis polymerization (ROMP) and various RDRP techniques (e.g., atom transfer radical polymerization (ATRP), nitroxide‐mediated polymerization (NMP), organometallic‐mediated radical polymerization (OMRP), and reversible addition–fragmentation chain transfer (RAFT)).…”

“…Similarly, a wide range of monomers have been used, including acrylates and methacrylates, acrylamides/methacrylamides, styrenics, olefins, vinyl esters, and epoxides . Both monomers must be compatible with the chosen polymerization technique and should ideally propagate rapidly and terminate relatively slowly in order to allow long chains to be prepared while maintaining acceptable levels of termination.…”

Effect of the Z‐ and Macro‐R‐Group on the Thermal Desulfurization of Polymers Synthesized with Acid/Base “Switchable” Dithiocarbamate RAFT Agents

“…RAFT‐synthesized polymers may also develop odor on storage due to the formation of volatile sulfur compounds (the latter is notably less of an issue with dithiocarbamates). As a response to these concerns, various end group removal techniques have been developed, which include reaction with nucleophiles (e.g., aminolysis, borohydride reduction), radical‐induced reactions (e.g., coupling, reduction, oxidation), and thermolysis . However, there are few studies on dithiocarbamate end group removal and none of these relate to the switchable RAFT agents.…”