Graft polymerization of acrylamide monomers from polysilsesquioxane containing xanthate groups

Abstract

Polysilsesquioxanes (PSQs) containing 4-chloromethylphenyl groups were prepared and used for introducing ethylxanthate groups. The obtained PSQs that contained benzyl xanthate structures (XAPSQs) were employed as macroinitiators for grafting acrylamide monomers. The use of XAPSQs for the radical polymerization with acryloylmorpholine (ACMO), N,N-dimethylacrylamide (DMAA) or N-isopropylacrylamide enabled the preparation of the respective grafted PSQ, in which no cross-linked product was formed. The results of the graft polymerizations from XAPSQs supported the interpretation that the reversible addition-fragmentation chain transfer polymerization progressed effectively using the technique known as macromolecular design via the interchange of xanthate. The introduction of polymerized ACMO and DMAA units provided an amphiphilic property to the grafted PSQ. In addition, the PSQs containing poly(ACMO) components showed reversible hydrophobic aggregation behavior at approximately 80°C in aqueous solution. The polysilsesquioxane (PSQ) containing ethylxanthate groups was used for the graft polymerization of several acrylamide monomers by MADIX process. The controlled graft polymerization gave the PSQs containing the polymeric components as the graft chains. The introduction of the polymers provided an amphiphilic property to the polysilsesquioxaneane. In addition, the grafted PSQ containing poly(acryloyl morpholine) showed a thermoresponsive property in an aqueous solution. The reversible hydrophobic aggregation of the polysilsesquioanes was observed at ca. 80°C.