The paper presents the results of investigations on the production of allyl ethers of phenolphthalein-containing novolacs, curable without release of low molecular weight substances, and cross-linked copolymers based on them.

By the interaction of formaldehyde with mixtures of phenol, phenolphthalein, and phthalimidine-containing bisphenols in the presence of an acidic catalyst, new co-oligophenol formaldehyde novolacs and crosslinked copolymers based on them are produced. Their properties are studied.

By the interaction of formaldehyde with blends of phenol, phenolphthalein (or a phthalide-containing monophenol), and m-cresol in the presence of an acid catalyst, new cresol-containing phenol formaldehyde novolacs and crosslinked copolymers based on them were obtained. Their properties were studied.Cresol-containing cooligomers of the resol type, based on blends of phenol, phthalide-containing phenols, and isomeric cresols (including m-cresol), are known [1]. Resols are noted for a high curing rate, and copolymers based on them have fairly high strength and thermal characteristics and are also possibly capable of exhibiting the effect of electronic switching under external effects, similarly to the known phenolphthaleincontaining resols [2]. However, along with the indicated advantages, the initial resols have one important shortcoming -reduced stability during storage and transportation, as the methylol groups contained in them nonetheless possess a certain reactivity.

Upon curing of novolacs SF-010 and SF-014 in the presence of dimethylol-p-cresol crosslinked phenolformaldehyde polymers were obtained. Their physicomechanical and thermal characteristics were studied. Optimal curing conditions were founded.