Research On Preparation And Propertis Of Melt Grafting Polyolefin Compatilizer

The compatibility of polyefins can be effectively enchanced with other polymer materials by melt grafting method, thus broadening the application of polyolefins.In this research, polyolefin-based compatilizers prepared by melt grafting to introduce into the polar/non-polar blend systems to validate the effectiveness of compatibilization and the mechanisms of compatibilization systematically investigated.Also, Compound matrix compatilizers were prepared and performances were researched.Firstly, a series of graft products were prepared by melt grafting method which had employed general polyolefins such as PP and PE were used as the matrix, DCP as the initiator and MAH or GMA as the monomers. The influences of graft monomer, co-monomer, initiator, reaction temperature and screw type on the grafting rate and the products' melt flow rate were respectively investigated the occurrence of GMA grafting reaction and showed that styrene, could improve graft as the second monomer. With the rise of loading of the graft monomer and the initiator, grafting yield first increased and then decreased. When the laoding of MAH, GMA and DCP were respectively 2.0 phr,4.0 phr and 0.08 phr, grafting yield met a peak. It was also found that the addition of styrene could furtherly improve the grafting yield and inhibit the side reactions. The best grafting effect was achieved when the loading ratio of the graft monomer and styrene was 1:1. The grafted product of HDPE met a drop of the melting point but a rise of the crystallization temperature, where as the graft of PP favored the heterogeneous nucleation and grain refinement.Subsequently, the compatilizer was introduced into PP/PA6 non-polar/polar blend system to investigate its effect on the mechanical properties by analyzing the morphology of the blend. It was found that when the content of PA6 was 20 phr, both PP-g-MAH and PP-g-GMA provided the maximum improvement in mechanical properties when the loading amount was 6.0 phr, which inferred that either PP-g-MAH or PP-g-GMA could be used as effective compatilizer because it could improve the interface bonding of PP/PA6 blend. It was also found that when the two graft products were compoundly used, the compatibilizing effect on the blend was even better.Lastly, PP and EVA, were blended with different loading proportions and then grafted by MAH and GMA simultaneously to prepared a compound matrix compatilizer, The effects of PP/EVA proportions in the compatilizer on the grafting rate and its melt flow rate, etc. were investigated. It was found that when the PP/EVA ratio in the compatilizer was 50/50, the compatibilizing effect on the PP/EVA blend was the best, but the grafting yield was too low because of the increase of side reactions. The melt flow rate of the blend increased with the increase of the EVA content. After grafting, the melting point and the crystallization temperature of the blend increased, tensile and flexural strength improved significantly. The SEM pictures showed that the compatibility of grafted PP/EVA blend was improved, and the number of large particles was significantly reduced. The results also showed that particles were significantly reduced. The results also showed that GMA performed more efficiently in grafting-compatibilization than MAH, no matter in a single matrix or a compound matrix.