Inlfuence of Extrusion Process and Screw Conifguration on Properties of Halogen-Free Intumescent Flame Retardant Polypropylene
Polypropylene (PP) was modified by halogen-free intumescent flame retardant (IFR) and the influences of the ex-trusion process parameters (extrusion temperature,screw speed,feeding quantity) and screw configuration on the properties [melt flow rate (MFR),mechanical properties,flame retardance,color) of halogen-free intumescent flame retardant PP materials were researched. The results show that with the increase of feeding quantity,the MFR,elongation at break and notched impact strength decrease in total,the proper feeding quantity is 60 kg/h. As the screw speed increases,the MFR increases,the elongation at break, notched impact strength and limiting oxygen index increase first and then decrease,the color of the material changes into yellow. With the increase of temperature,the elongation at break and notched impact strength of the materials also exhibit a trend of increas-ing firstly and decreasing lastly. The dispersion of the IFR in PP is poor while using weak shear screw configuration and the material degrades while using concentrate strong shear screw configuration,when using dispersed multi-stage shear screw configuration,the elongation at break and notched impact strength are improved obviously,which increase by 80%and 40.5%separately compared with those of weak shear screw configuration. The best performance of the material is received by using the following process condi-tions:the feeding quantity is set as 60 kg/h,the screw speed is set at 500 r/min,the extrusion temperature is set at 180–200℃, and the screw configuration is designed as dispersed multi-stage shear type.
NETL
NSTL
万方数据
维普
