Synthesis Of Polyester Plasticizer And Properties Of Plasticized PVC

Plasticizer was a kind of functional chemical product added to polymer to increase the plasticity of material and give the product softness.It was also the largest plastic additive in production capacity and consumption so far.At present,the aromatic phthalate plasticizers?DOP,DOTP,etc.?which are widely used at home and abroad are monomorphic plasticizers.Although they have high plasticizing efficiency,they have poor migration resistance and potential carcinogenicity.With the increasing requirements for the hygiene,environmental protection and high performance of plastic products,it was an inevitable trend to develop non-toxic,environmental friendly and efficient bio based plasticizer which can replace the traditional petroleum based o-benzene plasticizer.In this paper,a series of oligomeric polyester plasticizers were prepared from succinic acid and different diols,and the epoxy soybean oil modified polyester plasticizer was prepared by ring opening reaction of epoxy group.The effects of different side chain structures and modification methods on the plasticizing and durability of oligomer polyester were studied.Firstly,a series of oligomer polyester plasticizers were designed and synthesized from succinic acid and diols with different side chain functional groups.The effects of methyl,o-dimethyl,ethyl and chlorine functional groups of polyester side chain on the plasticizing effect and durability of oligomer polyester were studied by tensile test,dynamic mechanical property test and durability test.It is found that the plasticizing effect of PSch is better than that of other oligoester plasticizers when-Cl is added to the polyester side chain.When the addition of PSCH plasticizer is 40%,the plasticizing efficiency was 129.05%,and the elongation at break is 79.72%higher than DOP.The durability test results show that the mass loss rate of PSCH/PVC plasticizer under the same aging condition is lower than DOP.FTIR analysis showed that compared with DOP,the absorption peak of polyester C=O in PVC plasticized by PSCH shifted more to the lower wavenumber,which indicated that the polar group C=O in PSCH formed a large number of hydrogen bonds with?-H in PVC,the existence of hydrogen bonds increased the force between PVC and PSCH,at the same time,the introduction of polyester side chain CL increased the compatibility between plasticizer and PVC,and the stability of plasticizer in PVC increased.Secondly,epoxy soybean oil?ESO?grafted polyester was modified by ring opening reaction of epoxy group,and the synergistic plasticizing effect of ESO and polyester was studied.It was found that the grafted epoxy soybean oil effectively improved the plasticizing efficiency of polyester,the elongation at break of ESO-PSCH plasticized PVC film increased by 32%compared with that before modification,the glass transition temperature decreased to 4.31?,and the solubility parameter difference between ESO-PSCH and PVC was higher than that of unmodified PSCH.According to the gel theory,this is because the flexible segments of plasticizer increase after grafting epoxy soybean oil,which can block the opening of PVC molecules to plasticizing,and achieve synergistic plasticizing of epoxy soybean oil and oligomeric polyester.However,the content of polar groups is relatively reduced,thus reducing the compatibility with PVC.At last,the properties of PVC plasticized by PSCH and its modified product eso-psch were studied by MS simulation.The simulation results show that the MS simulation results are in good agreement with the experimental results.The results of solubility parameters showed that the compatibility of PSCH with PVC was slightly higher than that of modified polyester,and the binding energy of PSCH with PVC was273 J·mol^-1 higher than that of ESO-PSCH.The results show that the plasticizing effect of ESO-PSCH is better than that of PSCH.The young's modulus of ESO-PSCH is1.62GPa,which is 0.15GPa lower than that of PSCH/PVC.