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Two series of cyano-substituted polypentenamers and ·their hydrogenated derivatives have been studied by dynamic mechanical and dielectric relaxation in the temperature range from -160 to 110°C and at frequencies from 3.5 Hz to 10 kHz. Series I contains 7.4 mol % cyano groups and series II contains 20 mol % cyano groups. The amorphous cyanopolypentenamers display one major mechanical and dielectric relaxation region asso­ciated with motions accompanying the glass transition and labeled /3. A small secondary relaxation, labeled 'Y, is also discernible in the mechanical E" results. The semicrystalline hydrogenated derivatives exhibit three relaxation regions labeled a, /3, and 'Y …

Melting points (Tm's) and glass transition temperatures (Tg's) of stereoregular poly(methyl a-chlo­roacrylates), poly(ethyl a-chloroacrylates), and poly(isopropyl a-chloroacrylates) have been determined by differ­ential scanning calorimetry (DSC). Relaxation processes accompanying these Tg's and secondary relaxation phe­nomena have been studied by dynamic mechanical and dielectric relaxation. It was found that the extrapolated Tg values for high molecular weight syndiotactic poly(alkyl a-chloroacrylates) and high molecular weight isotactic po­ly(alkyl a-chloroacrylates) differed by the following amounts: 92° for the methyl esters; 83° for the ethyl esters; and 68° for the isopropyl esters. A secondary relaxation, labeled fl, and associated with motions of the ester side chains, …