Influence of Rare-earth Coupling Agent on Non-isothermal Crystallization Behaviour of Wood Flour/Polypropylene Composites
The influence of a rare-earth coupling agent (RE) on the non-isothermal crystallization behaviour of PP was studied by differential scanning calorimetry. Experimental results showed that use of RE caused a decrease in the crystallization temperature, melting temperature and crystallinity of PP in WF/RE/PP compared with those in WF/PP. The Avrami, Ozawa and Mo methods were used to describe the crystallization process. The Avrami and Ozawa methods neglected the secondary crystallization and followed primary crystallization. The Mo approach could successfully describe the overall crystallization process. The relation of the half times of crystallization (t1/2) of the three samples, t1/2(WF/PP) <t1/2(WF/RE/PP) <t1/2 (PP) and the F(T)(WF/PP)< F(T)(WF/RE/PP) <F(T)(PP), suggested that the crystallization rate of WF/RE/PP was slower than that of WF/PP The activation energy was calculated by using the Kissinger method and the results indicated that the incorporation of RE resulted in a compatible effect, which led to a reduction in the crystallization rate and an increase in activation energy compared with WF/PP.