Preparation And Application Of Liquid Barium-Zinc Composite Based Thermal Stabilizer

Large amount of polyvinyl chloride(PVC)is produced and used in China.Thermal stability of PVC products is poor and easy to decompose at high temperature,leading to reduced property.Hence,it is useful to improve the thermal stability by adding certain stabilizer.Currently,lead salts,organotin,metal soaps and rare earths are commonly utilized as heating stabilizers.Liquid barium-zinc composite based thermal stabilizer,a new type of metal soap heat stabilizer appears as green and environment friendly.It has caught more and more interest due to its excellent thermal stability,transparency,anti-precipitation and processability.In this study,isooctanoic acid salt and oleic acid salt were prepared by mixing isooctic acid,oleic acid,zinc oxide and barium hydroxide in white oil and diethylene glycol butyl ether.Validation of synthetic procedure was conducted through changing reaction time,temperature and the amount of organic acid on metal soap by titrating barium and zinc.The effects of different metal soap,metal mass ratio,phosphate ester,anti-precipitation agent,β-diketone,antioxidant,solvent and organic acid on thermal stability,precipitation,transparency and processability of PVC products were studied by using thermal aging oven method,double roll machine plastic refining method and rheometer.By introducing phenol-free antiprecipitant and phenol-free phosphite ester into the compound of heat stabilizer,it was found that the anti-precipitation property of pentaerythritol diisooctyl diphosphate was better than that of the common anti precipitation agent,and the heat stability of triisodecyl phosphite ester was better than that of the common phosphite containing phenol.The synergistic effects of each component was also analyzed,which was confirmed that the synergistic effects were from neutralizing HCl produced during PVC degradation,replacing unstable chlorine atom,eliminating unstable structure and passivating PVC degradation and catalysis.Based on these results,a better liquid barium-zinc composite based thermal stabilizer was afforded.Based on the laboratory research results,the industrial production of liquid barium-zinc composite based thermal stabilizer was carried out,and the annual output of liquid barium-zinc composite based thermal stabilizer(HBZ-1056A)reached 3000 tons.The performance analysis showed that the heat stability,processability,anti-precipitation and cost performance of the product were superior to those of the similar stabilizers at home and abroad.The PVC products processed by it meet the requirements of environmental protection and safety testing such as RoHS directive and PAHs standard,with the broad market application prospect and good social and economic benefits.