A Simple Route to Functional Highly Branched Structures: RAFT Homopolymerization of Divinylbenzene

Abstract

This work reports on a facile approach to the synthesis of highly branched polymers by the homopolymerization of commercially available divinyl benzene (DVB) via reversible additionÀ fragmentation chain transfer (RAFT) polymerization. The presence of RAFT agents allows conversions as high as 68% before crosslinking, instead of 15% for conventional free radical polymerization (FRP). The study extends this new approach by synthesizing starlike block copolymers of methyl acrylate (MA) and DVB by exploiting the living characteristic offered by RAFT polymerization. The resulting highly branched DVB polymers are used to produce in situ cross-linked polymeric particles following thermal stimuli. In addition, we exploit the large number of residual double bonds in the highly branched p(DVB) to further functionalize the polymer via thiolÀene click chemistry.

Controlled multi-vinyl monomer homopolymerization through vinyl oligomer combination as a universal approach to hyperbranched architectures

“…S2) and the precipitated polymer possessed a branch ratio of 66% (the percentage of divinyl-consumed branched units in all of the constructive units, Supplementary Fig. S3a), which is much higher than the previously reported MVM-derived polymers [30][31][32][33] . This high branch ratio indicates a highly branched structure formed from the enhanced intermolecular coupling rather than the traditional chain growth.…”

A rapid crosslinking injectable hydrogel for stem cell delivery, from multifunctional hyperbranched polymers via RAFT homopolymerization of PEGDA

“…We believed this reduction was caused by the increased possibility of the radical chain transfer and termination at the lower monomer/CTA ratio condition due to the higher chain/radicals density in small regions. It has been reported that the increased RAFT agent can significantly postpone the gel point [31][32][33] . Here, with the higher monomer/CTA ratio condition ([M] 0 :[CTA] 0 = 100:1), the molecular weight and distribution dramatically increased at the later reaction phase leading to the earlier gelation; in contrast this trend was significantly delayed with the lower monomer/CTA ratio (or in other words, with higher concentration of the RAFT agent) ( Figure 2C-D), which was consistent with the former studies.…”

Living Radical Polymerization by the RAFT Process – A Third Update

“…BA BA TEGMA MBAm [355] [ 355] DMAm 132 DEAm MBAm [571] PEGMA-b-EGMA 173 BA TEGMA [355] PEGMA 97 EGMA TEGMA [353] NIPAm 138 St DVB [419] -158 397 EGDMA [584] -158 -DVB [626] MA 158 -DVB [626] -23 DMAEMA 422 [256] 354 145 St 423 [427] PFPA PFPA PFPA tBA 179 -424 [461] NIPAm 179 -424 [461] A See footnote B of Table 3. cleavable imine linkages (Scheme 27).…”