The Evaluation of Psedue-Semi Interpenetrating Polyurethane network From FTIR and Swelling Test data based on polybutadiene-ol/polypropyleneoxide mixture

Polyurethane elastomer networks were designed and synthesized based on hydroxyl terminated polybutadiene/polypropyleneoxide (HTPB/PPO) mixtures, 2,4-toluene diisocyanate and 1,4- butanediol. Various networks with different molar ratio of HTPB to PPO (0/100, 25/75, 50/50, 75/25 and 100/0) had been prepared. DPS and HI factors caculated from FTIR spectrums. These factors show that chemical networks can increase hydrogen bonding and phase separation in polyurethane networks based on non-polar or semi polar soft segments. Moreover Flory–Hugins interaction parameters of soft and hard segments were calculated. Swelling tests were carried out with different solvents. Time-dependent and Equlibrium swelling test were studied with good and bad solvent for hard and soft segment. Synthesized polyurethane elastomer networks have a structure similar to semi interpenetrating polymer networks, which is named pseudo-semi-IPN.