US EPA

3859202 

Journal Article 

Tailor-made polyfluoroacrylate and its block copolymer by RAFT polymerization in miniemulsion; improved hydrophobicity in the core-shell block copolymer 

Chakrabarty, A; Singha, NK 

2013 

Yes 

Journal of Colloid and Interface Science
ISSN: 0021-9797
EISSN: 1095-7103 

Academic Press Inc. 

408 

1 

66-74 

English 

23953650 

10.1016/j.jcis.2013.07.031 

WOS:000323989900010 

Controlled/living radical polymerization (CRP) of a fluoroacrylate was successfully carried out in miniemulsion by Reversible Addition Fragmentation chain Transfer (RAFT) process. In this case, 2,2,3,3,4,4,4-heptafluorobutyl acrylate (HFBA) was polymerized using 2-cyanopropyl dodecyl trithiocarbonate (CPDTC) as RAFT agent, Triton X-405 and sodium dodecyl sulfonate (SDS) as surfactant, and potassium persulphate (KPS) or 2,2'-azobis isobutyronitrile (AIBN) as initiator. Being compatible with hydrophobic fluoroacrylate, this RAFT agent offered very high conversion and good control over the molecular weight of the polymer. The miniemulsion was stable without any costabilizer. The long chain dodecyl group (-C12H25) (Z-group in the RAFT agent) had beneficial effect in stabilizing the miniemulsion. When 2-cyano 2-propyl benzodithioate (CPBD) (Z=-C6H5) was used as RAFT agent, the conversion was less and particle size distribution was very broad. Block copolymerization with butyl acrylate (BA) using PHFBA as macro-RAFT agent showed core-shell morphology with the aggregation of PHFBA segment in the shell. GPC as well as DSC analysis confirmed the formation of block copolymer. The core-shell morphology was confirmed by TEM analysis. The block copolymers (PHFBA-b-PBA) showed significantly higher water contact angle (WCA) showing much better hydrophobicity compared to PHFBA alone. 

Core-shell morphology; Fluoroacrylate; Miniemulsion; RAFT polymerization