Synthesis And Properties Of Tung-Oil Based PVC Complex Stabilizers

As the demand for environmental protection is becoming stronger and stronger, it will bequite significant and promising to develop a new kind of thermal stabilizer and co-stabilizerwith high efficiency and low toxicity. In this paper, tung-oil based stabilizers and tung-oilbased co-stabilizer were synthesized by methyl eleostearate. The research results as follows:Firstly, TODC, TOTC and TOTL were prepared by tung-oil based polybasic acidmethyl ester. Their structures were confirmed by Metal Elements Analysis, FTIR and XRD.The thermal stability of poly（vinyl chaloride）（PVC） upon doping Ca（St）2, Dimer acidcalcium, TODC, TOTC and TOTL were determined by means of the Congo-red test, heataging test and TG. The results showed that: TOTC has better initial dyeing property andlong-term heat stability, that adding means ring structure and many functional fatty acids canbeneficial to improve heat stability of PVC products.Secondly, eleostearoyl-benzoyl methane（EBM）were prepared by claisen reaction ofmethyl eleostearate and hypnone as raw materials,using the sodium methoxide as catalyst. Inthis paper,its structure was confirmed by FTIR and GC-MS. The material proportion,reaction temperature reaction time of catalyst impact on the yield of EBM was tested by areanormalization.The optimal reaction conditions indicated by L9（34） orthogonal experiment wereas follows: n（methyl eleostearate）:n（hypnone）=1.2︰1,with0.6％by weight of hypnoneused as catalyst dosage, reaction temperature was maintained at110℃for4h. Effect ofcontents of EBM on heat stability of PVC was tested by means of the Congo-red test and heataging test methods. The results showed that: adding EBM can effectively improve the initialcoloring but its thermal stability would not improved.Then, the influence of PVC processability and heat stability of TOTC/ZnSt₂,TOTL/ZnSt₂and TOTC/ZnSt₂/TOTL were tested by means of torque rheometer, TG,congo-red test and heat aging test methods for research the influence of rare earth heatstabilizer effect on calcium/zinc composite heat stabilizer system. The results showed that TOTL can improve the heat stability and processing rheological property of TOTC/ZnSt₂system. In TOTC/ZnSt₂/TOTL ternary composite system, its thermal stability time canreached43min when3g TOTC/ZnSt₂/TOTL（mTOTC︰mZnSt₂︰mTOTL=12︰3︰10） ternarycomposite stabilizer was added into100g PVC/40gDOP.Finally, calcium carboxylates of tung oil C₂₂triacid （TOTC） were prepared by doubledecomposition reaction of C₂₂triacid monomethyl ester （MEMAA） in this paper. Its structurewas confirmed by FTIR.The influence of the initial dyeing property and heat stability ofTOTC-ZnSt₂system upon doping TPP, PER, DT were studied by means of the congo-redtest and heat aging test methods. On that basis, the best formula of tung acid-based C₂₂triacidCa-Zn composite stabilizer was obtained by orthogonal intersection tests. The results showedthat tung acid-based C₂₂triacid Ca-Zn composite stabilizers have the best heat stability whenmTOTC﹕mZnSt₂︰mDT︰mTPP︰mPER=48︰12︰2︰5︰10. When3g tung acid-based C₂₂triacid Ca-Zn composite stabilizer made by the optimum formula was added to the100g PVC∕40g DOP, its static thermal stability time could last for50min at185℃.Compared withsome commercially available products,its showed better static thermal stability,even similarto that of imported products.