Synthesis Of Acrylate Copolymers With Core-Shell Structure And Its Modification For PVC

The acrylate copolymers(ACR) with core-shell structure were synthesized by seed emulsion polymerization used butyl acrylate, 2-ethylhexyl acrylate, styrene, methyl methacrylate as comonomers.The emulsoid particle size and its distribution were determined by dynamic laser scattering and TEM. The composition changes of ACR were inspected by IR, and the core-shell structure was observed by TEM. The results indicated that the emulsoid particles have core-shell structure obviously, its diameters are between 100 to 160nm. The glass-transition temperatures were measured by DSC, the results showed that there are three glass-transition temperatures in ACR.The properties of PVC/ACR blends, such as notched impact strength, tensile strength, thermal stability and rheological properties were determined. TEM was employed to examine the dispersion state and the fractured surfaces of PVC/ACR blends. The effects of the amount of emulsifying agent, initiator and crosslinking agent, ratio between core and shell, monomer composition, solid content of emulsion, polymerization temperature, the amount of ACR in PVC/ACR blends on mechanical properties were discussed. The results showed that the ACR can uniformly disperse in the blends. The notched impact strength of PVC/ACR blends was improved remarkably and the tensile strength of the blends have not obviously changed. The fractured surface of the sample showed the shape of toughness fracture. The notched impact strength of PVC/ACR blends was increased to about 3-4 times than the PVC when the ratio of PVC/ACR is 100/6(wt). The thermal stability and rheological properties of the PVC were also improved.The ACR is an effective modifier for improving impact strength of PVC.