The reactions of peroxides with polymers have been studied for some time. They form an extensive part of vulcanization technology. Two types of reactions are generally recognized, those leading to crosslinking between polymer chains and those leading to scission of the chains. Natural rubber, polybutadiene and ethylene-propylene rubber are examples of polymers in which crosslinking reactions take place to a greater extent than reactions leading to chain scission and these polymer reactions with peroxides form a useful method of vulcanization. On the other hand, polyisobutene is an example of a polymer which degrades extensively and for polyisobutene and butyl rubber, peroxides have not found use as cross-linking agents.

Acyloxy derivatives of silicon were prepared by the interchange reaction between carboxylic acids (including various grades of palmitic acid) and tetraethoxysilane, and by the interchange reaction between palmitic acid and technical ethyl silicate (silica content 40%) or technical isopropyl silicate (silica content 38%). In most of the reactions, sodium methoxide was used as catalyst. Some physical properties of the reaction products were determined, and the materials made from palmitic acid were evaluated as water‐repellent coatings on cotton cloth.

The reaction between chlorophosphazenes and silicon alkoxides has been studied as a means of preparing temperature‐stable thermosetting resinous materials. If the silicon alkoxide is polyfunctional in straight‐chain lower alkoxy groups the usual reaction is elimination of alkyl chloride and formation of a thermosetting resinous product. The mechanism of this reaction is discussed. Other reactions occurring in the treatment of chlorophosphazenes with silicon alkoxides are also discussed. Asbestos laminates which retain much of their strength when heated to 500° for 50 hours in air can be prepared from the thermosetting resinous products resulting from the reaction between chlorophosphazenes and silicon alkoxides.