Effect of the Alkyl Side-Chain Structure on Melting Point of Atactic Poly(alkoxycarbonylmethylene)s: Incorporation of Amide-Linkage Leading to Polymers with High Melting Point
Hiroaki Shimomoto, Itsuki Katashima, Hirokazu Murakami, Tomomichi Itoh, Eiji Ihara
Abstract
Diazoacetates with a variety of alkyl groups as an ester substituent were prepared and polymerized by Pd-based initiating systems to afford atactic poly(alkoxycarbonylmethylene)s (PACMs), and the effect of the alkyl side-chain structure on thermophysical properties [melting point ( T m ) and glass transition temperature ( T g )] was investigated with differential scanning calorimetry analyses. The use of a series of linear and two-way-branched side chains with various alkyl chain lengths was not so effective for raising T m of the PACMs. On the other hand, the incorporation of an amide-linkage in the middle of the linear alkyl chains is quite effective for raising T m because of the hydrogen-bonding interaction among the amide-linkages of the alkyl side chains, where the spacer length between the ester- and amide-linkages is crucial for raising T m . The highest T m around 130 °C was attained with the spacer length of C4 with the outer alkyl chain lengths of C7 and C9.