The reactive in situ compatibilization of polyvinyl chloride (PVC) and polystyrene (PS) was realized in melt blending through Friedel-Crafts reaction between PVC and PS with anhydrous aluminium chloride as catalyst.The melting temperature of blending PVC and PS decreased from 160℃ to 140℃; Impact toughness of the blends was improved through pre-milling and adding styrene monomer.PVC/PS alloy materials with favorable comprehensive mechanical performance were successfully prepared.The structure and properties of PVC/PS alloy materials were characterized by Fourier transform infrared spectroscopy (FTIR)

differential scanning calorimetry (DSC)

scanning electron microscopy (SEM) and tests of mechanical properties.The results show that the peaks of 1943 cm-1and 838 cm-1 in FTIR spectrum proves the substitution for para-position of benzene

the glass-transition temperature of the blend is 89℃ between 83℃ of PVC and 106℃ of PS.SEM photos show interface adhesion of PVC with PS became better and better with addition of anhydrous alluminium chloride and styrene in proper order.When the mass fraction of PS

anhydrous alluminium chloride and styrene is 6%

0.6% and 9%

strengthening and toughening of PVC were realized

the tensile strength increased from 49.35 MPa to 60.54 MPa

the notched impact strength of the blends material reached 5.3 kJ/m2

compare with 3.9 kJ/m2 of PVC

increased by 35.9%.