Study On Low-halogens Flame-retardant PVC/PNBR Thermoplastic Elastomer

PVC(polyvinylchloride)/NBR(nitrile-butadiene rubber) thermoplastic elastomer possesses higher tear strength, higher abrasion resistance, resistance to oil and so on. So this elastomeric blend can be used in the industry to replace conventional rubber. However, in order to process easily, it requires an organic plasticizer, such as DOP [di (2-ethylhexyl) phthalate] filled at varying levels to make the PVC materials flexible. The plasticizer (DOP) has a dramatic effect on the flammability. So the blend can cause a serious fire disaster compare with rigid PVC. In order to enhance flame retardance of blend, MH(Magnesium hydroxide) and some flame-retardant synergists could be added in blend.In this work, low-halogens flame-retardant PVC/PNBR thermoplastic elastomer was studied. The mechanical properties, flame retardance and thermal stability of blends were investigated. Moreover, surface modification of MH particles was examined.The effect of lead salt stabilizers and stearate stabilizers on the dehydrochlorination of low-halogens flame-retardant PVC/PNBR thermoplastic elastomer was studied by Congo red method. The experimental results showed that effectiveness of 3PbO was better than that of 2PbO in terms of inhibiting of dehydrochlorination of PVC/PNBR thermoplastic elastomer when they were used respectively. The dehydrochlorination temperature of PVC/PNBR thermoplastic elastomer was improved when 3PbO and 2PbO were used mixing. The initial dehydrochlorination time of PVC/PNBR thermoplastic elastomer was longer than that with addition of 2PbO, but lower than that with addition of 3PbO.The initial dehydrochlorination time of PVC/PNBR thermoplastic elastomer was over 50min when 3phr Bast or 6phr Cast with flame ratardants were used respectively. However, Znst as stablizer was unefficient when single used in PVC/PNBR thermoplastic elastomer. The thermal degradation stability of PVC/PNBR thermoplastic elastomer was improved when m(Bast)/m(Cast), m(Bast)/m(Znst) and m(Cast)/m(Znst) were 3:1,2:1 and 2:1 respectively. When the Bast/Cast/Znst mixture was used, and...