Mechanical Properties and Interfacial Interaction of Modified Calcium Sulfate Whisker/Poly(Vinyl Chloride) Composites

Calcium sulfate whiskers (CSWs) modified with glutaraldehyde-crosslinked poly(vinyl alcohol) (PVA) or traditional surface modifiers, including silane coupling agent, titanate coupling agent and stearic acid, were used to strengthen poly(vinyl chloride) (PVC), and the morphologies, mechanical and heat resistant properties of the resulting composites were compared. The results clearly show that glutaraldehyde cross-linked PVA modified CSW/PVC composite (cPVA@CSW/PVC) has the strongest interfacial interaction, good and stable mechanical and heat resistant properties. Nielsen's modified Kerner's equation for Young's modulus is better than other models examined for the CSW/PVC composites. The half debonding angle θ of cPVA@CSW/PVC composite is lower than that of other composites except silane coupling agent modified CSW/PVC composites, indicating a very strong interfacial adhesion between cPVA@CSW and PVC. In general, cross-linked PVA is effective and environmentally friendly in modifying inorganic fillers.