An n.m.r. and d.s.c. investigation of the solubility conditions of didecylphenylphosphite in rigid poly(vinyl chloride)

Abstract

It is shown from n.m.r. measurements that didecylphenylphosphite used as a thermal co-stabilizer is not completely dissolved in rigid poly(vinyl chloride) (PVC). D.s.c. measurements however, show a marked effect on the glass transition temperature of PVC, which implies that the co-stabilizer is dissolved to some degree in the PVC phase. Although this effect on the glass transition temperature proceeds continuously with the added amount of the co-stabilizer, d.s.c. measurements alone cannot give a full description of the solubility conditions. Nor can the effects observed by d.s.c. be used to give criteria for a complete solubility.