Waste Pet Base With Excellent Rigidity Toughness Of Engineering Plastics

As polyethylene terephthalate (PET) in the packaging area was rapid growth in consumption, the consumption of waste PET was also increasing at a rate of roughly the same. RPET's recycling had become an important subject.of energy saving and recycling. The research on the modification which make the rPET as engineering plastics was increasing attention both at home and abroad in recent years, because rPET still had high-rigidity, high heat resistance and chemical stability, It had the important economic and social significance, especially for engineering plastics consumption and mainly relies on large imports of China.Two aspects of science and technology problems should be resolved if the rPET could be used as engineering plastic. First, enhanced toughness; second, improved crystalline behavior, speeded up the crystallization rate and reduced the molding temperature. The research had made significant progress, but the obvious problems are existed that how to improve rPET's toughness and rigidity at the same time.In order to get the modified rPET with excellent toughness and rigidity, the idea was proposed that introducing the ductile components and the rigid components to rPET together. The ductile components contained functional groups that can react to both rigid components and rPET; The ductile components could be enriched the interface between rPET and rigid components, and come into appropriate flexible interface with high adhesion by self-assembly.Based on this designing idea, the R type MFMB (R-MFMB) was synthesized through the technique "low viscosity reaction system, grafting copolymerization, reactive blending" using HDPE, ethylene-propylene elastomer, styrene-butadiene rubber, containing epoxy functional groups of crosslinking agents (C) and auxiliary crosslinking agents (S). The rPET / R-MFMB/GF composites with good mechanical properties were prepared by reacting blend. Furthermore, the chemical structure and composition of R-MFMB, the mechanical properties, melt flow, crystal morphology, morphological structure and chemical structure of rPET/R-MFMB/GF had been studied by solvent extraction grade, IR, TEM, PLM. The main results and conclusions are as follows: (1) R-MFMB contained the following components: the unreacted HDPE and elastomer, grafting and cross-linking reaction can process between HDPE and two elastomers, the branched chains and/or bridge chains between HDPE and elastomer and the photopolymer and copolymer of the two bridge-agents.(2) Ta of R-MFMB was first increasing then decreased and Tc increased with the epoxy compound ratio increasing during R-MFMB preparation. Tc of R-MFMB was increasing and Ta was decreasing with the C+S increasing during R-MFMB preparation.(3) With the content of R-MFMB increasing, the NIIS of rPET/R-MFMB was slightly improved; but FM and TYS was slightly lower; With the epoxy compound ratio increasing during R-MFMB preparation, the NIIS, FM and TYS of rPET/R-MFMB were firstly increased, and then decreased; With C+S increasing during R-MFMB preparation, NIIS of rPET/R-MFMB were increased, FM and TYS remained basically unchanged, and MFR gradually lowed.(4) Epoxy functional group of the R-MFMB in rPET/R-MFMB/GF composites could be reaction with -OH, -COOH in the rPET and also with the-NH₂ of the GF surface; R-MFMB could be enriched in the interface between the rPET and GF, and come into an high strength of appropriate flexible interface.(5) With the content of R-MFMB increasing, mechanical properties of rPET/R-MFMB/GF composites were firstly increased, and then decreased. With the content of GF increasing, mechanical properties of rPET/R-MFMB/GF composites were gradually increased. When the ratio of rPET/R-MFMB/GF composites was 55/15/30, mechanical properties of rPET/R-MFMB/GF were best: NIIS, FM, TYS are 3.52 times, 3.21 times and 2.43 times than those of rPET.