Design, Synthesis, And Characterization, Of The Star Polymer

Star polymers were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. Using 2-(Benzyl sulfanyl thiocarbenyl sulfanyl) Ethanol (BSSE) as RAFT agent, n-Butyl acrylate (nBA) as monomer, we synthesized star polymers via miniemulsion polymerization and solution polymerization. These star polymers were characterized by means of GPC, IR, and DLS.Star polymers based on PBA/HDDA were prepared in nanoreactor of miniemulsion using reversible addition-fragmentation chain transfer (RAFT) polymerization. The chain transfer agent 2-(Benzyl sulfanyl thiocarbenyl sulfanyl) Ethanol (BSSE) was used to prepare the linear macro RAFT agent PBA. The influences of surfactant (sodium dodecyl sulfate, SDS), co-stabilizer (hexadecane, HD) and reaction tempreture on the RAFT/miniemulsion polymerization were studied. The results confirmed that the molecular weights of the polymers produced were increased linearly with the conversions of the monomer. Then introduced HDDA into the miniemulsion of PBA, star polymers were formed. The molecular weight of the star polymers was invariable and the polydispersities was low (typically<1.1).Star polymers based on PBA/HDDA were synthesized by "arm-first" method via solution polymerization. First, the linear macro RAFT agent PBA was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. Then, the star core formed by using HDDA as the cross-linker. The molar ratio of HDDA to PBA affected the conversion of the star polymers. Molecular weight and distribution of the linear macro RAFT agent PBA and the star polymers were characterized by gel permeation chromatography (GPC). The results confirmed that the molecular weight of the star polymers was invariable and the polydispersities was low (typically<1.1).