ABSTRACT
It was determined (79) that the partial hydrolysis of phosphites that arises during storage does not deplete their melt-stabilizing performance. The high efficiency of hydrolyzing aliphatic phosphites, accompanied by their fast consumption, was evidenced during processing of polyolefins (78,79). On the contrary, aromatic phosphites are hydrolytically resistant, and their consumption is slower at the expense of their activity. Phosphites without fully suppressed hydrolyzability, such as mixed aliphatic-aromatic phosphites (RO)P(OAr)2, which release phenols after hydrolysis, may be considered as a compromise. Similarly, a combination of partially hydrolyzable and hydrolytically resistant phosphites may account for an enhanced performance. In the mentioned combination, the more effective phosphite is consumed faster.
