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Synthesis Of Poly (Trioctylammonium P-Styrenesulfonate) Homopolymers And Block Copolymers By Raft Polymerization, Yuqing Liu, Kevin Pollock, Kevin Cavicchi
Synthesis Of Poly (Trioctylammonium P-Styrenesulfonate) Homopolymers And Block Copolymers By Raft Polymerization, Yuqing Liu, Kevin Pollock, Kevin Cavicchi
Kevin Cavicchi
A method to prepare sulfonated polystyrene-containing block copolymers has been investigated by neutralizing styrene sulfonic acid with trioctylamine to produce the hydrophobic monomer trioctylammonium p-styrenesulfonate (SS–TOA). This monomer was polymerized by reversible addition fragmentation chain transfer (RAFT) polymerization to produce PSS–TOA homopolymers. A PSS–TOA homopolymer was then used as a macro-RAFT agent for the polymerization of styrene to prepare poly(trioctylammonium p-styrenesulfonate)-block-poly(styrene) (PSS-TOA-b-PS). These block copolymers could be ion-exchanged to produce either the hydrophilic sodium salt form of PSS or a hydrophobic quaternary ammonium salt. This approach will be useful for preparing PSS-containing block copolymers with a range of hydrophobic blocks …
Synthesis And Characterization Of A Poly (Styrene-Block-Methylacrylate-Random-Octadecylacrylate-Block-Styrene) Shape Memory Aba Triblock Copolymer, Pengzhan Fei, Kevin Cavicchi
Synthesis And Characterization Of A Poly (Styrene-Block-Methylacrylate-Random-Octadecylacrylate-Block-Styrene) Shape Memory Aba Triblock Copolymer, Pengzhan Fei, Kevin Cavicchi
Kevin Cavicchi
A new shape memory polymer (SMP) was prepared from an ABA triblock copolymer with polystyrene (PS) end blocks and a random copolymer midblock of poly(methylacrylate-random-octadecylacrylate) (PMA-r-PODA). The self-assembly of the triblock copolymer generates a three-dimensional, physically cross-linked network by the bridging of the midblocks across the glassy PS domains, which is used as the permanent network in the SMP. A second reversible network is generated by the side-chain crystallization of the PODA side-chains. Shape memory testing by uniaxial deformation and recovery of molded tensile bars demonstrated that shape fixities greater than 96% and shape recoveries greater than 98% were obtained …