Ultra-high molecular weight polyethylene (UHMWPE) with a microporous structure was prepared via thermally induced phase separation (TIPS). Liquid paraffin (LP) was used as a diluent in the preparation of microporous UHMWPE. Small angle laser light scattering (SALLS) and differential scanning calorimetry (DSC) were used to determine the phase separation temperatures

i.e. the cloud points and the dynamic crystallization temperatures

respectively. It was found that the cloud points were coincident with the crystallization temperatures

indicating that a solid-liquid phase separation occurred during thermal quenching of the UHMWPE/LP solution

while

no liquid-liquid phase separation above the crystallization temperature was observed. The effects of the content and the molecular weight of UHMWPE on the morphology and average pore size were investigated with field emission scanning electron microscopy (FE-SEM) and mercury porosimetry. With the increase of the content of UHMWPE

the average pore size of the microporous material decreased and the molecular weight of UHMWPE could also influence the pore size slightly.