Versatile Approach for Preparing PVC-Based Mikto-Arm Star Additives Based on RAFT Polymerization

Zhonghe Sun, Mu Wang, Zhi Li, Bonnie Choi, Roger J. Mulder, Anchao Feng, Graeme Moad, San H. Thang

Research output: Contribution to journalArticleResearchpeer-review

14 Citations (Scopus)


A versatile approach to the synthesis of migration-resistant poly(vinyl chloride) (PVC) additives is described and a preliminary assessment of their properties is presented. The process involves the synthesis of AB2 3-mikto-arm stars, star-[PVC-block-(polyB);(polyB)2] or star-[PVC;(polyB)2], that contain a reversible addition-fragmentation chain transfer (RAFT)-synthesized PVC segment, to provide compatibility with PVC and good migration resistance, and multiple RAFT-synthesized segments (polyB), where polyB is based on more activated monomer (a styrene or a methacrylate) that contains the functionality required to impart the desired additive properties. The approach to PVC-based stars comprises three steps: (a) synthesis of a hydroxy-functional PVC [X-PVC(OH)n] by RAFT polymerization mediated by a hydroxy-functional xanthate [X-(OH)n], (b) conversion of the X-PVC(OH)n to the corresponding trithiocarbonate, X-PVC-(CDTPA)n, by the Steglich esterification with 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid (CDTPA), and (c) formation of star polymer additives by RAFT polymerization mediated by X-PVC-(CDTPA)n. The stars prepared include a plasticizer (B = butyl acrylate), a reactive dispersant for use in forming silica nanocomposites (B = 3-methacryloxypropyltrimethoxysilane), UV stabilizers (B = 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate or 2-hydroxy-4-acryloxybenzophenone), and flame retardants (B = 4-vinylbenzyl phosphonate or (diethoxyphosphoryl)methyl methacrylate). Although much optimization remains to be done, our preliminary study shows that the synthesized mikto-arm star additives can be effective in imparting the anticipated properties to PVC.

Original languageEnglish
Pages (from-to)4465-4479
Number of pages15
Issue number11
Publication statusPublished - 9 Jun 2020

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