Interfacial sythesis of polyphosphonate and polyphosphate ester. VII. Temperature effects and reaction loci in polycondensations of hydroquinone with phenylphosphonic dichloride and 4‐methythiophenyl phosphorodichloridate

Abstract

AbstractPolyphosphate and polyphosphonate esters of molecular weights > 10,000 were synthesized by base‐promoted, liquid‐vapor and liquid‐liquid interfacial polycondensations of hydroquinone (HQ) with 4‐methylthiophenyl phosphorodichloridate (MTPP) and phenylphosphonic dichloride (PPD). The barium hydroxide‐initiated liquid‐vapor polycondensation of PPD and HQ in the temperature range of 15–95°C shows that [η] increases with reaction temperature and unfractionated yields exhibit a maximum at about 45°C. The analogous liquid‐vapor polycondensation of MTPP and HQ between 25 and 854C also shows a maximum yield at 45°C, whereas [η] decreases with increase in reaction temperature. The results are contrasted with temperature dependencies of base‐catalyzed, liquid‐liquid polycondensation of HQ with MTPP and PPD. A different insight is obtained by analyzing the temperature effects on fractionated products. The relative importance of degradative saponification reactions are ranked as attack on chain ester linkages > phosphorus chloride reactant > end groups of growing chains.