Synthesis of PPC-graft-poly(PEOMA) Brush and PPC Gels via Post-polymerization Modification of Hydroxyl-Functionalized Poly(propylene carbonate)

Abstract

Post-polymerization modi cation offers a facile and effective tool for adapting polymer properties. However, it has not been applied to poly (propylene carbonate) (PPC) as traditional PPC lacks su cient functional groups along the polymer chain. In the present work, for the rst time, hydroxyl-functionalized PPC has been prepared and used to construct PPC-brush and cross-linked polymer gels through postpolymerization modi cation approach. PPC-brushes in the form of PPC-graft-poly (PEOMA) were obtained with controllable brush length and brush density via "grafting from" a PPC-macroinitiator which was synthesized from esteri cation reaction of PPC-OH with 2-bromoisobutyryl bromide. PPC permanent networks in the form of dioxane gels were prepared by cross-linking PPC-OH with 4,4′-diphenylmethane diisocyanate (MDI). Rheological measurement of the gels showed that the cross-linking density scales linearly with the hydroxyl group density in PPC-OH. This work not only offers a facile strategy to realize the post-modi cation of PPC but also spurs the devising of innovative biodegradable materials with tailored molecular architectures.

Poly(Propylene Carbonate)-Based Biodegradable and Environment-Friendly Materials for Biomedical Applications

“…For instance, He et al prepared a cross-linked PPC network in the form of dioxane gels by cross-linking PPC-OHs with 4,4′-diphenylmethane diisocyanate (MDI) as the cross-linking agent. The cross-linked PPC gels exhibited an enhanced thermal stability [ 108 ]. Another important modification of the terminal -OH of PPC is grafting of water-soluble polymers such as PEG [ 13 , 109 , 110 ], which improves the water-solubility of PPC.…”