THERMAL AND STRUCTURAL CHARACTERIZATION OF POLY(METHYLENE-1,3-CYCLOPENTANE) SAMPLES OF DIFFERENT MICROSTRUCTURES

The thermal properties and the crystalline structure of poly(methylene cyclopentane) samples with different microstructures are investigated. Similar disordered crystalline structures are formed, independently o f the microstructure of the sample. These structures present hexagonal packing of the chain axes and extended chains with configurational an d conformational disorder, which generate intermolecular rotational an d translational disorder. The distance between adjacent parallel chain s decreases with the increase of rings with the cis configuration; cor respondingly, the melting temperature strongly increases. Both interch ain distances and melting temperatures seem poorly dependent on the re lative stereochemistry between rings. The degree of crystallinity and the correlation length of the crystalline domains tend to increase wit h the stereoregularity in the configuration of the rings (both cis and trans). The melting entropy increases with all the examined kinds of stereoregularity (cis, trans, and isotactic).