Phosphorus-containing polymers from THPS. VII. Synthesis of phosphorus-containing trialkynes and their metal-free 1,3-dipolar cycloaddition reaction with azidated soybean-oil

Abstract

A novel hydrolysis-resistant trialkyne, namely tris(prop-2-yn-1-yloxy methyl)phosphane oxide (TPOPO) was prepared from an environmentally friendly tetrakis(hydroxymethyl)phosphonium sulfate (THPS). The chemical structure of TPOPO was characterized by FT-IR, NMR (¹H, ¹³C, ³¹P) and MS. The TPOPO underwent metal-free and solvent-free 1,3-dipolar cycloaddition reaction with azidated soybean oil (AzSBO) at different alkyne/azide molar ratios. The gel contents of the cured polymers were higher than 95% and the char yields of polymers at 850 °C were over 16.4%. DMA analysis showed that the glass transition temperatures were over 45.9 °C. The cured polymers showed high dielectric constant and dielectric loss due to their high polarity.