Affiliation:
1. N.N. Nesmeyanov Institute of Chemical Physics, Russian Academy of Sciences
2. N.L. Dukhov “All-Russian Scientific Research Institute of Automation” Federal State Unitary Enterprise
Abstract
By differential scanning calorimetry, and from the buildup of longitudinal shrinkage, a study was made of the kinetics of structural relaxation during the low-temperature annealing of biaxially oriented polypropylene film. It was established that the first, rapid stage of structural relaxation normally occurs in the process of product manufacture. The second, slow stage, comprising the process of secondary crystallisation, occurs in the course of storage and service. The kinetic parameters of secondary crystallisation and accompanying longitudinal shrinkage that make it possible to predict the kinetics of these processes in a wide range of temperatures and observation times were determined.