Compounding Chlorinated Polyethylene Elastomers for High Temperature Service

Abstract

The inherent chemical inertness of peroxide cured, chem ically saturated CPE elastomers provides an opportunity for the formula tion of compounds with excellent resistance to high temperature environ ments. Data contained in this paper demonstrate that, with the proper choice of compounding ingredients, elongation and tensile losses less than 25% after aging 7 days at 302° F (150°C) in air can be attained. In the same compounds compression set can be kept below 30% (70 hrs at 302° F). To take advantage of these desirable heat aging properties, low mole cular weight plasticizers or extender oils, the mineral fillers evaluated in this study, and high reactive lead stabilizers must be avoided. Polymers with lower chlorine content should be chosen when heat aging is im portant. The antioxidant level should be minimized because antioxidants usually interfere with peroxide cure systems Compound contaminants, such as zinc oxide, should be minimized in CPE elastomer compounds that are expected to heat age. It is hoped that the information contained in this paper will assist the rubber chemist in developing new or improved elastomeric compounds that meet many of the current and future requirements for high temperature service

Up-scale pseudo-telescopic photo-induced Arndt-Eistert α-amino acids homologation in flow reactors cascade

“…Similar investigation of the patent literature showed a sum of 500 records (according to SciFinder search). Although there are 150 patents related to flow photochemistry in the period from 1981 to 2004 (which does not line up with the journal articles analysis), these documents mostly feature high tonnage chemical processes [78][79][80][81][82] and polymers and films production [83][84][85][86] or wastewater treatment [87][88][89][90] . In order to properly fit this data with the journal paper analysis we did the same cut as before and found that the trend and numbers for the patents (Figure 1 E, chart in blue) are similar to the trends and numbers for papers.…”