Preparation Of Ultra-fine Waste Tire Rubber (WTR) And Studies On The Structure And Property Of WTR/PP/SBS/Iron Composites

In this paper, ultra-fine waste tire rubber (WTR) powders were prepared by pan-milling, a mechanochemical route based on a complex combination of shearing, compression, stretching and friction actions. The changes of the shape, microstructure and particle diameter caused by pan-milling were investigated. The structure and properties of WTR/PP, WTR/SBS, WTR/PP/SBS composites prepared through pan-milling techniques were investigated. A novel sound insulation composite with good mechanical performance based on WTR/PP/SBS/Fe composite was obtained. The experimental results indicated that pan-milling was feasible for pulverizing coarse rubber particle to ultra-fine size at ambient temperature in wet state, and for preparing waste rubber based composites and functional materials, especially for polymer/metal composite with high metal content. The main conclusions were as follows:(1) In this paper, super-fine waste tire rubber powders with diameter 0.3-5μm were prepared through the pulverization of coarse waste tire rubber powders by pan-milling in wet state, using water-surfactant mixture as dispersing medium. The content of particle size smaller than 1μm was more than 85%. The experimental results indicated that super-fine WTR powders dispersed very well in water and showed high hydrophilic property.(2) Powders and composites PP/SBS, WTR/SBS,WTR/PP/SBS were prepared and effect of pan-milling on WTR/PP/SBS composite was especially studied . SEM and Hakke plasticator showed that the dispersion ability and processing properties of composites were enhanced by stress induced effect of pan-milling. WTR based composites with good mechanical properties with high WTR contents( ≥ 45%) was obtained. The mechanical properties of WTR/PP/SBS had much higher than that of WTR/PP at 20%-25% SBS loading content, especially from 39.2% to 221.9% with 466.1 % higher in elongation at break and from 14.92KJ/m' to 25.83KJ/m1 with 73.1% higher in Izod impact strength at 25% SBS content. Moreover, there was no change in tensile strengthand break strength.(3) Polymer/iron composite with uniform dispersion of iron in polymer matrix with high metal contents was prepared through pan-milling. The experimental results suggested that WTR/PP/SBS/Fe composite with 3mm thick had a good sound insulation, the sound loss achieved 28dB at 60% iron content. WTR/PP/SBS/Fe composite with 80% iron content still showed satisfactory mechanical property. So, it was feasible to prepare polymer/metal composite with high metal loading through pan-milling technique.