Preparation And Characterization Of PET/HDPE Compatibilized Blends

In order to make full use of the rigid nature of polyethylene terephthalate?PET?and expand the application field of PET,this article uses melt blending method to blend PET with high-density polyethylene?HDPE?in order to prepare excellent performance blend material.However,PET and HDPE belong to a thermodynamically incompatible system.Simply blending the two cannot meet the needs of material performance improvement,and may even have an adverse effect.Therefore,this article chooses to add a compatibilizer to the blend to improve the compatibility and improve the properties of the blended material.The compatibilizer was prepared using two thermoplastic elastomers,namely ethylene-1-octene copolymer?POE?and styrene-butadiene-styrene block copolymer?SBS?as the matrix.Glycidyl methacrylate?GMA?and styrene?st?were selected as grafting monomer and graft-promoting co-monomer,respectively.Two different reactive compatibilizers,POE-g-GMA and SBS-g-GMA,were prepared by melt grafting under the initiation of dicumyl peroxide?DCP?.The effects of the amount of graft monomer?GMA+St?in the graft modifier?compatibilizer?on the mechanical properties,thermal properties,melt viscosity,and microphase morphology of the PET/HDPE?80:20?blend were investigated.It was found that the notched impact strength and elongation at break of PE4 sample reached their maximum values when the amount of grafting monomer in POE-g-GMA was 4 phr,which were 66.8 J/m and 25.5% respectively.For PET/HDPE/SBS-g-GMA blends,the notched impact strength and elongation at break were the highest when the amount of grafting monomer was 8 phr,which were 33.1 J/m and 24.1%,respectively.DSC test showed that the crystallization temperature of PET in the blends decreased by 9.9 ? and 14.6 ? with the increase of the amount of grafting monomer.MFR also decreased with the increase of the amount of grafting monomer,and then gradually became flat.The phase region observed by SEM also confirmed the change rule of mechanical properties,which showed the fibrous structure between the matrix and the dispersed phase and the "core-shell" particles structure.After determining the amount of grafting monomer in the compatibilizer,by changing the amount of the graft compatibilizer,the effects of the amount ofcompatibilizer on the properties of PET/HDPE blends were explored and discussed.The crystallization kinetics of the PET phase in the blend was addressed.When the content of compatibilizer was 15 phr,the mechanical properties of P₁₅E sample and P₁₅S sample reached the highest value,the notched impact strength was 97.9 J/m and 44.8 J/m respectively,and the elongation at break was 38.6% and 36.3% respectively.Compared with the pure PET and P0 sample without compatibilization,the toughness of the blends increased significantly.DSC test and crystallization kinetics analysis showed that the increase of compatibilizer content would hinder the crystallization of PET phase in the blend,and POE-g-GMA had more obvious effect on the crystallization of PET phase,but it would not change the growth mode of three-dimensional spherulites of PET phase.The MFR of the blends decreased with the increase of compatibilizer content,up to 5.4g/10 min,and the T_g of PET and HDPE would be close to each other.SEM showed that the size and dispersity of the dispersed phase in the blends improved with the increase of compatibilizer content.