THE METHOD OF EXPRESS EVALUATING OF RUBBERS QUALITY FOR CONTEMPORARY PRODUCTION PROCESSES

Abstract

A universal method for quick assessment of the quality of rubbers has been developed, based on the determination of the molecular weight distribution (MWD) and branching of the rubber structure (DCR) using the RPA-2000 device (Alpha Technologies inc.). The reciprocal of changes in tan δ (1 / Δtgδ) with a change in the test frequency at a temperature of 100 °C and a constant amplitude of deformation is uniquely related to the value of MMD, and the magnitude of change in Δtgδ with a change in the amplitude of deformation and a constant frequency is associated with DSB. The proposed methods for the quick assessment of MWD and DCR of rubbers in emulsion and solution polymerization for 24 samples obtained under various conditions of the production process are compared with the results of using the traditional method of gel permeation chromatography (GPC). The coefficients of reliability of the approximation (R²) are 0,8 and 0,9, which indicates a correlation between the values obtained by the two methods. The advantage of the proposed method is the reduction of the analysis time, since the sample preparation is carried out directly in the device chamber. The developed express method is universal and allows you to quickly predict changes in the structure and properties of rubber under the chang of the parameters of the technological regime in the production process, to minimize the risk of getting low-quality products, by timely adjusting the parameters of the technological process.