Effect of the molecular weight of polymer and diluent on the performance of hydrophilic poly(vinyl butyral) porous heddle via thermally induced phase separation

Hydrophilic Poly (vinyl butyral) (PVB) porous heddles were prepared via blending hydrophilic PVB and green diluent Polyethylene glycol (PEG) through liquid-liquid thermally induced phase separation (TIPS) process. To further investigate the effect of the molecular weight (MW) of polymer and diluent on phase diagram of PVB-PEG blending system and performance of hydrophilic PVB porous heddle, the cloud point (Tcloud), microstructure, overall porosity and mechanical property, i.e were mainly analyzed. The results highlighted that the Tcloud of the PVB-PEG blending shifted to lower temperature with increasing PEG MW and PVB MW. Overall porosity reached up to 82.3% and tensile strength was 9.88 MPa when polymer and diluent with lowest MW. To extend the application air, the fabrication conditions of prepared porous heddle were studied. Overall porosity increased and the tensile strength decreased with extrusion temperature increasing. In addition, the PVB-PEG porous heddles proved effective hydrophilic performance and demonstrate the potential application in water treatment.