Synthesis of Peroxide Monomers Based on Unsaturated Carboxylic Acids

Peroxide monomers, i.e., compounds whose molecules contain double carbon carbon bonds and peroxy groups, are used in the preparation of copolymers having peroxy groups as substituents in the macrochain. Such copolymers are efficient modifiers and activators of polymeric surfaces [1]. Among peroxy monomers in which the peroxy group is linked to two tertiary carbon atoms, only derivatives of isopropenylbenzene [2] and 2-methyl-3-hexen-5-yn-2-ol [3] are known. The goal of the present work was to synthesize new peroxy monomers derived from methacrylic or maleic acid and 3-tert-butyldioxy-3-methyl-1-butanol. Initial hydroperoxide I was prepared by alkylation of tertbutyl hydroperoxide with 3-methyl-1,3-butanediol in the presence of sulfuric acid. Monomers II and III were obtained by acylation of compound I with an equimolar amount of methacryloyl chloride or maleic anhydride, respectively (Scheme 1). The products are stable to shock and friction, and they can be stored for a long time without loss of active oxygen. Copolymerization of II and III with other monomers, such as styrene, -methylstyrene, etc., gives rise to peroxy-containing copolymers. 3-tert-Butyldioxy-3-methyl-1-butanol (I). To a mixture of 39.7 g (0.38 mol) of 3-methyl-1,3-butanediol and 35.7 g (0.38 mol) of tert-butyl hydroperoxide we added dropwise with stirring at 35 40 C 57.2 g (0.38 mol) of 65% sulfuric acid. The mixture was stirred for 2 h at that temperature, diluted with an equal volume of water, neutralized with MgO, and extracted with hexane. The organic layer was separated and dried over MgSO4, the solvent was distilled off, and the residue was distilled under reduced pressure. Yield 57.1 g (85%), bp 64 C (1.3 kPa), d4 20 = 0.9216, nD 20 = 1.4266, MRD = 49.05 (calcd. 49.38). IR spectrum, , cm : 960 (COOC), 820 (O O), 1200 (C O), 1020 (C OH), 3368 (OH). H NMR spectrum, , ppm: 1.15 s (9H, t-Bu), 3.77 t (2H, OCH2), 1.83 t (2H, CH2), 1.25 s (6H, 2CH3),