Incorporation of hydroxyl endgroups in vinyl polymer. Part I. Initiation by hydrogen peroxide systems

Hydroxyl endgroups were incorporated in polymers of methyl methacrylate obtained by initiation with hydrogen peroxide with the monomer in bulk and in aqueous solution. Hydroxyl endgroups in the respective polymer samples were estimated by means of the dye interaction technique. Aqueous photoinitiation with hydrogen peroxide was found to incorporate an average of about 1–1.5 hydroxyl endgroups per polymer chain, depending on the concentration of the initiator used. Aqueous thermal (60°C.) polymerization leads to an average of nearly 1 hydroxyl endgroup per chain. Polymerization in the dark at room temperature was carried out by activation with Fe2+ and Fe3+ ions, and an average of nearly 1 hydroxyl endgroup per chain was obtained in both cases. Bulk polymerization (photo‐ and thermal) produces polymer having nearly 1.3–1.7 hydroxyl endgroups per chain.