Study On Toughening Modification Of Polybutylene Terephthalate By Functionalized Composite

A series of poly(butadiene-graft-styrene)core-shell impact modifiers(PB-g-PS)and glycidyl methacrylate(GMA)functionalized PB-g-PS(PB-g-PSG)with different GMA content were synthesized by seeds emulsion polymerization.The effect of the degree of functionalization of the modifier on the toughening effect of PBT was investigated.Then,PBT/PB-g-PSG1 system was chosen to study the effect of the free segment of PB-g-PSG1 modifier on the toughening of PBT.Finally,on the basis of studying the modification of PBT with one modifier,the two modifiers ABS-g-GMA and POE-g-GMA were used to toughen PBT together.By adjusting the ratio of the two modifiers,the relationship between the common use of modifiers and PBT performance was studied.The results as follow:(1)The equilibrium torque,elastic modulus,and yield strength of the blend system increased with the increment of GMA content.The degree of functionalization of PB-g-PSG showed a certain effect on the compatibility between the matrix and the modifier.The higher the GMA content,the better the dispersion of the modifier in the matrix.For the impact strength value of the blends,the introduction of GMA made the toughening effect of PB-g-PS core-shell modifiers on PBT significantly improved.The introduction of 1% GMA within the system resulted in the greatest improvement in the performance of the blend.(2)The free segments in PB-g-PSG1 played a very important role in the process of modifying PBT.The presence of free segments made the compatibility between the modifier and the matrix better.And the impact strength of the blends was significantly increased.But the free segments nearly had no effect on the tensile properties of the blends.(3)The combined use of two modifiers,ABS-g-GMA and POE-g-GMA,allowed the elastic modulus and the yield strength of the blends achieved the valve between the two modifiers used alone.And the values obtained under different proportions nearly had no difference.The common use of the two modifiers resulted in a 12-fold increase in elongation at break of the blend compared to pure PBT,which effectively improved the ductility of the blend before breaking.The impact test results showed that by adjusting the ratio of the two modifiers,PBT blends with higher toughness and better overall performance were obtained.