The Preparation Of PP/PET Blends And Their Compatibilizers

Polypropylene(PP)has the advantages of easy processing,good heat resistance and low cost while polyethylene terephthalate(PET)shows good mechanical properties.And PP/PET blends have become widely used when the two materials are mixed.The blends not only retain their original excellent properties,but also have better barrier and durability.However,as PP and PET are typical thermodynamic incompatible systems,their further development is limited.Therefore,it is necessary to prepare non-toxic compatibilizers with high toughness and strength.Since glycidyl methacrylate(GMA)is non-toxic,graft side reactions are few and functional group activity is high,and ethylene octene copolymer(POE)and PP have good mixing capacity and toughening effect,therefore,POE-g-GMA,as the capacity enhancer of PP/PET blends,has been widely concerned by scientists.First of all,a series of PP/PET blends were prepared by melting and blending though the way of adding POE-g-GMA with different contents,which showed the comprehensive properties of PP/PET blends were studied by impact text,tensile text,DMA and other test methods.Through the analysis of mechanical properties,it was found that when the content of POE-g-GMA was 15%,the PP/PET blends exhibited brittle-ductile transition,at which time the elongation at break increased to 496.01%and the impact strength increased to 63.28 kJ/m~2.The DMA test found that the glass transition temperatures of PP and PET were close to each other.The SEM results also proved the law of mechanical properties and compatibility.Meanwhile,DSC and XRD tests also found that the addition of POE-g-GMA inhibited PP crystallization and induced PP to generate?crystals.Secondly,POE-g-GMA with different grafting rates was synthesized by melt grafting method and then added to PP/PET blends.The effects of POE-g-GMA with different grafting rates on the properties of PP/PET blends were studied.According to the test results of impact,tensile and DSC,when the content of POE-g-GMA was 15%and the grafting rate was 2.02%,the elongation at break of PP/PET blends were as high as 897.26%,which greatly enhanced the toughness of the blends,indicating that the interaction between POE-g-GMA and PET was enhanced.No obvious two-phase structure was observed by SEM.And PET was uniformly dispersed in PP,the two components were mixed together,indicating that the compatibility between PP and PET was significantly improved.