Transesterification of Poly(4,4′‐isopropylidene‐2,2′‐dimethyldiphenylene terephthalate) and Poly(ethylene adipate) Blend in Solution

Abstract

AbstractSummary: Transesterification of poly(4,4′‐isopropylidene‐2,2′‐dimethyldiphenylene terephthalate) and poly(ethylene adipate) (PEA) has been carried out in concentrated o‐dichlorobenzene solution at 210 °C with Bu2SnO as a catalyst. According to GPC data, during transesterification the reaction product acquires Flory MWD and only a slight degradation of chains proceeds in the system: on average each chain having undergone about one scission in 100 min. Chain structure of the reaction products was studied using 1H NMR spectroscopy. The kinetic and statistical analysis of the process was performed using following assumptions: transesterification proceeds in a homogeneous medium as a reversible second‐order reaction between diads, and the product chain structure obeys the first‐order Markov statistics. Calculated dependences of the parameters characterizing an evolution of the chain structure during the reaction fit experimental data fairly well. In 100 min the reacting system reaches a state close to the equilibrium. The difference between distributions of diads of residues and units is considered.Change of the terephthalate‐centered r‐triads content with time.magnified imageChange of the terephthalate‐centered r‐triads content with time.