Preparation Of Hyperbranched Polymer Modified Nonmetallic Fraction Of Recycled Pcbs And Its Application In Rubber Composites

PCB recycling has always been a worthy subject,but because of the complex structure and the large surface energy,the PCB powder is difficult to disperse in the rubber,which has greatly restricted its function as a reinforcement of rubber.Because of unique properties,the hyperbranched polymers can be used for graft modification of rubber fillers.In this paper,HPC/NMF/NR composites were prepared by means of grafting to,and their structures and properties were studied.The addition of HPC can effectively improve the curing performance,mechanical properties and interface effect of NR composites.When the1.66phr HPC is added,the tensile strength and tearing strength of the composites reach the maximum,which is increased by 13.80%and 31.65%compared with the pure NR.The waste NMF after adding hyper-branched polyester shows good dispersibility in NR,and the bonding of filler-rubber matrix is enhanced,which shows excellent interfacial effect.In this paper,HBP-NMF was prepared by using the method of grafting from,and used in NBR.The structure and properties of HBP-NMF/NBR were studied.The degree of HBP-NMF is about 20.70wt%.The addition of HBP-NMF decreased the vulcanization time,improved the total crosslinking density and enhanced the tensile and tear strength of the composites.With the addition of 15phr filler,the tensile strength of HBP-NMF/NBR composites increased by 35.5%and 28.2%,and the tear strength increased by 24.4%and 5%,respectively,compared with NMF/NBR and KH550-NMF/NBR.When the filler content is30phr,the tensile strength,the 100%elongation stress and the tear strength of HBP-NMF/NBR composites increase to 15.67MPa,5.58MPa and 54.17 kN/m.The hybrids modified by hyper-branched polyamines showed good dispersion and excellent interfacial effect in NBR.In order to further enhance the rubber composite,HBP-NMF/Zn?NO₃?₂/NBR was prepared,and its structure and properties were studied.The rich hyper-branched terminal amino groups were entangled with the rubber chain,and formed a coordination bond with the nitrile group in NBR and zinc ions.When the addition of Zn?NO₃?₂ was 6phr,the tensile strength reached the maximum,which increased by 109.12%compared with the blank sample.The addition of zinc salt can improve the thermal oxidation resistance and oil resistance of the composites.The interface study of HBP-NMF/Zn?NO₃?₂/NBR composite was found that the composite has a rough cross section and less glass fibers are pulled out.There is synergistic effect between the original covalent bond network and the newly formed non-covalent bond cross-linking network.The interfacial effect is enhanced,and the mechanical properties of the composite can be improved obviously.