The Preparation Of POE-g-(GMA-co-St) And Study On The Compatibilization Of PET/LDPE Blends

Polyester container packaging materials account for 40%of current plastic products,and it is the main part of domestic household waste.At the same time,the amount of polyethylene waste that is one of the four general-purpose plastics is also increasing.The establishment of recycling cycles for waste plastics has been imperative.PET/PE alloy has a lot of advantage,if recycled PET and PE can be prepared for the PET/PE alloy,can for PET and PE recycled material market,explore new application provides a new solution.However,the key of the preparation of PET/PE alloy is the choice of compatilizer.Based on the characteristics of PET and LDPE,this paper finds a compatibilizer that can improve the compatibility of PET/LDPE blends.The thermoplastic elastomer ethylene-octene copolymer(POE)was used as the grafting agent,glycidyl methacrylate(GMA)and styrene(St)as grafting monomers,which were obtained by melt grafting and solution grafting.The synthesis method was used to determine the best formula of the synthetic compatibilizer POE-g-(GMA-co-St)and the best compatibilizer POE-g-(GMA-co-St)was prepared.By Fourier transform infrared spectroscopy,it was confirmed that the functional group GMA had been attached to the POE molecular chain,confirming that the melt grafting reaction was effective.Through testing of mechanical properties,it was found that when the addition amount of compatibilizer reached 15 phr,the composite material changed from brittle fracture to ductile fracture.When the addition amount was 20 phr,the impact properties of the blend reached 756 J/m,and the tensile strain was 716%.The dynamic mechanical properties and SEM images also confirmed the internal factors of mechanical properties change.By DSC,the non-isothermal crystallization kinetics of composites was explored.With the increase of the amount of compatibilizer,the crystallinity X_c of PET increased from 37.89%to 51.82%and then decreased to 37.51%.For the crystallization behavior of LDPE,the experimental results show that the addition of a compatibilizer will promote the crystallization of LDPE.POE-g-(GMA-co-St),a compatibilizer,was prepared by solution grafting method.The optimum reaction time of solution grafting reaction was determined by characterizing the grafting degree,mechanical properties,crystallization properties and interface morphology.The mechanical properties test confirmed that the impact strength of the blend fluctuates with the increase of reaction time,and the fluctuation range is 55 J/m-76 J/m.The optimal reaction time was 9 h and the grafting degree was 28.04%,which was 181.5%higher than that of the un-compatibilized blend.By analyzing the SEM images,the microscopic phase morphology of the blends explains the relevant conclusions obtained from the mechanical properties.The DSC test showed that the grafting agent with too high degree of grafting inhibited the crystallization of PET/LDPE blends,and the X_c of PET decreased from 20.12%to 14.73%.