Synthesis and Characterization of a Poly (styrene-block-methylacrylate-random-octadecylacrylate-block-styrene) Shape Memory ABA Triblock Copolymer
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 for extensional strains up to 300%. Although some loss of properties was observed with cycling, the entirely physically cross-linked nature of the polymer allowed erasing of the sample history and recovery of the initial properties by annealing the sample at elevated temperature.
ACS Applied Materials and Interfaces
Fei, Pengzhan and Cavicchi, Kevin, "Synthesis and Characterization of a Poly (styrene-block-methylacrylate-random-octadecylacrylate-block-styrene) Shape Memory ABA Triblock Copolymer" (2010). Polymer Engineering Faculty Research. 1378.