Surface modification of magnesium hydroxide sulfate hydrate whiskers and its toughness and reinforcement for polyvinyl chloride

In order to enhance the adhesion and compatibility of magnesium hydroxide sulfate hydrate (MHSH) whiskers with polyvinyl chloride (PVC), and prepare high performance MHSH/PVC composites, chitosan (CS) is coated on the surface of MHSH whiskers by a facile method. The effect of the CS‐coated MHSH (CS‐MHSH) whisker and its toughness and reinforcement for PVC are studied. A thin layer coated on the surface of MHSH whiskers after modification is investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The efficacy of surface modification is confirmed by fourier transform infrared spectroscopy (FTIR), X‐ray power diffraction analyses (XRD) and energy disperse spectroscopy (EDS). The optimum modification concentration of CS is 0.025%. The notched impact strength and flexural modulus of PVC composite with 15 phr CS‐MHSH whiskers are increased by 85.5% and 58.5% compared with those of pure PVC, and by 48.3% and 4.1% compared with those of the PVC composite with 15 phr unmodified MHSH whiskers. A better thermal stability of CS‐MHSH/PVC composite is showed by thermogravimetric analysis (TGA). Dynamic mechanical analysis (DMA) result indicates that CS‐MHSH whiskers have a better dispersion and a stronger interfacial adhesion with PVC matrix. POLYM. COMPOS., 39:3676–3685, 2018. © 2017 Society of Plastics Engineers