Solvent-free and biodegradable pressure-sensitive adhesive based on chlorosulfonated Poly(propylene carbonate)

Abstract

The challenge of pressure-sensitive adhesives (PSAs) is to develop solvent-free and biodegradable PSAs. By chlorosulfonated reaction of poly(propylene carbonate)s (PPC) and sulfuryl chloride, a series of biodegradable and solvent-free chlorosulfonated poly(propylene carbonate)s (CSPPCs) with different molecular weight have been acquired. Different from the traditional fabrication of PSAs, introducing polar groups (sulfur and chlorine atoms) onto PPC is combined with the degradation of PPC. For CSPPCs, the elasticity is related to the molecular weight, and the viscosity is related with the polar groups contents, resulting that the balance of the molecular weight and the polar groups contents is significant to adhesion properties. Among CSPPCs, the balance of molecular weight and the polar group contents is most appropriate and the peel strength is highest, when the number-average molecular weight is equal to 15.5 kg/mol. In addition, peel strength can be further improved by chain extension or crosslinking of CSPPCs. From the point of view of environmental protection, the fabrication of CSPPCs is a new and economical method of producing biodegradable and solvent-free PSAs to meet the ever-increasing demands of society.