Research On The Reuse Of Recycled PVC Wire And Cable

Polyvinyl chloride(PVC) is one of the top five most versatile plastics. PVC’s volume is only next to polyethylene(PE) worldwide. Nevertheless, PVC annual output is largest in China yet. With its wide application in all kind field, the volume of waste PVC is larger and larger. Dumping or incinerating waste PVC in outdoors not only pollutes the environment, also the resources cannot be used sufficiently. Therefore, it’s critical to study how to reuse waste PVC in high-quality. The usage of PVC in wire and cable is about take 7% of whole PVC production. Hence, how to reuse waste PVC wire and cable is indispensable and could provide good references for recycling other waste plastics.First, this thesis measured the component contents in rPVC and characterized its properties. Solution-precipitation method 、 thermogravimetric method and extracting-thermogravimetric method have been compared to study their accuracy in measuring content of PVC resin, plasticizer, inorganic fil er contained in rPVC. The results show that extractingthermogravimetric method has the best accuracy, and the error of this method is less than 5%. Additionally, the consequence of studying relationship between thermal aging time and infrared spectrum of rPVC indicated that the double bond index and thermal aging time have good linearity. Based on this, Arrhenius equation have been used to compute the thermal aging active energy of rPVC, the value is 133.9KJ/mol. The non-isothermal kinetics study of rPVC implies that rPVC still has long remaining service life.Thereafter, the thesis was devoted to reusing rPVC in wire and cable. Although the mechanical properties of rPVC are good enough to meet the using standards(GB/T 8815-2008), the thermal aging resistant ability and thermal stability do not fulfill the specification of the standard. Hence, CaCO3, MMT, HG and CaSiO3 were incorporated in rPVC and KH560, KH570, NDZ coupling agent were used to modify the four kind inorganic fil ers. As a result, the incorporation of four inorganic fil ers can ameliorate rPVC’s thermal aging resistant ability. However, the mechanical properties of rPVC presented to be decreasing in different degree. When the additional content is 10 phr, the tensile strength of CaCO 3, MMT, HG, CaSiO3 fil ed rPVC declined respectively by 4.9%, 12.6%, 25.9%, 22.9%. After modified by coupling agent, the mechanical properties of fil ed rPVC improved apparently. Besides, rPVC’s thermal aging resistant ability and thermal stability also improved further more. Eventual y, the fil ed rPVC can meet using requirements.Finally, ABS/rPVC blends were prepared through milt blending and the influences of content of rPVC on mechanical properties, processing properties, thermal stability and fracture micromorphology of ABS/rPVC blends were explored. To ameliorate the properties of blends, rPVC was pretreated before melt blending and CPE was added in blends. The results show that mechanical properties decreases with the content of rPVC increasing. When the addition of rPVC was 30 phr, the tensile strength, flexual strength, impacted strength and vicat softening temperature of ABS/rPVC blend decreased from 47.8MPa, 76.9MPa, 11.7KJ/m2, 94.1 ℃ to 35.8MPa, 53.4MPa, 7.0KJ/m2, 78.4 ℃ respectively. After rPVC was pretreated for 24 h and 10 phr CPE was incorporated in blend, the mechanical properties of prepared blend were near to virgin ABS. Besides, the prepared blend will self-extinguish when was burning in the horizontal direction.