All-union conference on relaxation effects in polymers

The Effect of Modification of Polymers on their Structure and Properties

“…Purposeful investigation of the effect of heat treatment on the structure and physical properties of polymers of various classes enabled one of the present authors to formulate the fundamental "fork" rule and its corollary [5,9,25,26]. This rule states: "The characteristics of the structures and all physical properties of polymers in the initial state always occupy an intermediate position in relation to the corresponding values of quenched and annealed specimens".…”

“…To predict the changes in the properties of the polymers during their storage, during their service under conditions close to real conditions, and with different types of modifi cation, it is expedient to use the method of plotting and analysing Debye spectrograms [5,7]. This is particularly effective when temperature or frequency dependences of the mechanical or dielectric losses are available, obtained with different modifying parameters (plasticiser or fi ller concentrations, radiation dose, temperature and time of heating) of specimens subjected to heat treatment.…”

“…To describe the processes of heat treatment, a multiparametric equation of the form F( γ s tr ,ξ med ,T i nit ,ω + ,T he at ,t heat ,ω -,T fi n ) = 0 (5) was proposed. Here, γ str is a parameter characterising the structural organisation of the polymer (the degree of crystallinity, the density, the crosslink density), ξ med is a factor corresponding to a certain medium in which heat treatment is carried out (liquid, air, inert gas, vacuum), T init is the initial temperature from which heating of the specimens is carried out, ω + is the heating rate of the specimens in continuous or stepped (cascade) schedules, T heat is the heating temperature of the specimens in the heating chamber, t heat is the heating time of the polymers in the corresponding medium, ωis the cooling rate of the specimens in continuous or cascade schedules, and T fi n is the temperature to which the specimens are cooled after their annealing.…”

“…Comparative analysis of the quantitative characteristics for polymers of different classes showed that the use of differential dependences is more effective since for the maxima it is possible to use a larger number of parameters (four) by comparison with the integral dependences, for which one or two parameters are typical. In earlier studies [5,6], on the basis of an analysis of numerous experimental data, the physical meaning of each of the four parameters was established. The temperature of the appearance of a maximum (or minimum) characterises the intensity of intermolecular interaction of the polymers.…”

Study of the Relationship between the Composition, Structure, and Physical Properties of Block Copolymers Based on Flexible and Rigid-Chain Components

“…The production of block copolymers from solutions (with various solvents) leads to a sharp change in the phase morphology and also to phase inversion, which is accompanied with a change in the height ratio of the two peaks of mechanical losses. The more pronounced the continuity of the matrix phase, the higher is its corresponding peak at a prescribed composition of the composites [12].…”