| Most of the beverage containers are PET blow-molded bottles,and the quantity of waste plastics caused by discarding them after drinking increases sharply with the rapid development of the bottled beverage industry.The chemical stability of PET material is excellent,so it can’t be degraded in a short time easily.It has caused serious plastic pollution,which brings extreme damage to the social environment.Recovery and modification of PET bottles can not only protect the environment,but also achieve resource recycling,which meets the social concept of green environmental protection.Due to its slow crystallization and narrow processing temperature range,the recycled PET is difficult to be injection molded directly,and the products are easy to crack caused by its poor toughness,thus doesn’t have much practical value.Mixed with ASA to get r-PET/ASA alloy is an efficient way to improve its processing performance and mechanical properties.In this work,recycled polyester bottle fragments(r-PET)and acrylonitrile-acrylate-styrene copolymer(ASA)were used as matrix material to make r-PET/ASA alloys,which were modified by Styrene-maleate copolymer(SMA),Vinyl-acrylate-glycidyl ester copolymer(EBGMA),Styrene-n-phenylmaleimide-maleic anhydride(MSNIP)as compatilizers.DSC method was used to evaluate the compatibility and crystallization performance of the mixed r-PET/ASA alloys,and SEM method was used to characterize the cross-section structure and compatibility of the two components.In addition,the mechanical properties of the alloys were analyzed by standard injection molded specimens to discuss the influences on the structure and performances due to different formulas.PET/ASA alloy was prepared by extrusion using a twin-screw extruder with a screw diameter of 35 mm and an aspect ratio of 44:1.SMA,EBGMA and MSNIP were chosen as compatilizers to modify the original system.The results showed that when MSNIP was used as compatibilizer and added by 5% in a system with a ratio of 30:70between r-PET and ASA,its capacity performed well,and the notched impact strength which used to represent toughness could reach up to 15 k J/m2.This work also studied the alloy’s flame retardancy.With the introduction of environmental brominated flame retardants,the alloy could reach V-0,and had a performance change of less than5% after acid and alkali resistance and other chemical reagents,meanwhile the trace index of leakage resistance was more than 500 V.The amplification tests were performed by twin screw extruders with an aspect ratio of 44:1 and screw diameters of both 50 mm and 65 mm.Compared to the alloy obtained by twin screw extruders with an aspect ratio of 44:1 and screw diameter of35 mm,the r-PET and ASA alloy properties had a coincidence degree of more than 90%.As a result,the massive production of r-PET and ASA alloy is highly feasible and has great practical application and promotion value.The typical applications of r-PET/ASA alloys are electronics and electrical appliances.The price differentiation between flame/non-flame r-PET/ASA alloys and their potential substitute productions is 3000-1000 RMB/T,which has significant economic benefits.R-PET/ASA alloys provide an alternative solution for PET bottles’ recovery and modified reuse,which can protect the environment and create economic benefits. |
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