Study On Preparation Of Polystyrene/Polyolefin Alloy

The PP/PS alloy was prepared by the process of melt blend extruding and the PS/PO alloy was prepared by the method of reactive extrusion. The mechanical property and rheological property both were studied. SEM was also used to observe and analyze the phase dispersion of the alloy. Results showed that the addition of SBS to the immiscible PP/PS blends resulted in the improvement of the compatibility between two components. The interfacial layer formed between PP phase and PS phase led to the increase of impact and tensile strength and the decrease of modulus. Also SEM showed that the size of the disperse phase of PP/PS alloy compatibilized by SBS decreased and the interface between two phases was not clear. The impact strength of the PS/PO alloy compatibilized with AlCl3 was improved greatly and the tensile strength increased too, but the modulus of the alloy decreased. FTIR showed that the copolymer LLDPE-g-PS formed in situ reactive extrusion. The crystallization of the alloy was investigated that by DSC. It was indicated that the copolymer affected the crystallization behavior of the alloy and the crystallinity decreased greatly. And SEM showed that the size of the disperse phase of the alloy with addition of AlCl3 decreased greatly from 1um to 0.3um. At the same time, the fracture of the blends was coated with gold directly and it was showed that there were a lot of fibres in the fracture. MFR of the PS/PO alloy increased, which suggested that the degree of degradation increased. Based on the former study, styrene was added to the PS/PO alloy. It was indicated that the impact and tensile strength were improved greatly, but the modulus of the blends decreased. And MFR of the PS/PO alloy decreased to some extent, which indicated that the degree of degradation decreased. SEM showed that the size of disperse phase decreased with addition of styrene to the PS/PO alloy and the interfacial layer between two components increased.