Research On PBS Composite Modified With Hyperbranched Polymer

HBP(Hyperbranched polymer) with a large number of end groupshas highly branched three-dimensional structure. It has low viscosity,high solubility, high reactivity, film-forming properties and goodcompatibility with other polymers. The synthetic method of HBP issimple. PBS(Poly butylenes succinate) has high crystallinity, whichmakes the material brittle and harder to degrade. In this research, HPBis used to modify PBS to decline the crystallinity of PBS and toimprove its performance. The inorganic is added to the composite asthe third component, in order to improve the comprehensiveperformance of the composite, reduce costs, expand the use of PBSand extend the applied range of the hyperbranched polymers used asadditives.(1) HBPU(Hyperbranched polyurethane) is synthetized byIPDI(Isophorone diisocyanate acid) and DEA(Diethanol amine).IR(Infrared spectrum) is used to characterize the structure of HBPU.The blending technology of HBPU and PBS is explored.HBPU/PBS(poly butylene succinate) composite films with differentcontents of HBPU are obtained through banburying blending first andthen mixing rolling. The thermal property, crystallization behaviorand mechanical performance of HBPU/PBS composites areinvestigated by DSC(Differential scanning calorimetry), TG(Thermo-gravimetry), XRD(X-Ray Diffraction) and universal testing machine.The degradation property is also studied using the soil burial methodin Shaanxi garden soil(In the greenhouse of Shaanxi University ofScience and Technology). The results show that, with HBPU contentincreasing, the thermal performance of the HBPU/PBS compositedecreases linearly. The crystallization temperature of the PBSimproves with HBPU, while the degree of crystallinity of HBPU/PBS composite decreases. The elongation at break of HBPU/PBScomposite improves significantly. When the content of HBPU is6%,the elongation at break of the composite is3times as that of PBS. Thetoughness of the material improves greatly. There are obvious crackson the HBPU/PBS composite film degraded after3months comparedwith pure PBS film. HBPU could speed up the degradation of thecomposite film.(2) HBPU of different chain length, structures with dihydroxygroup as the end group are synthetised to improve the thermalproperty of HBPU/PBS composite. The thermal property andmechanical performance of HBPU/PBS composites are investigated byTG and universal testing machine. The results show that, as the carbonchain length increases, the heat resistance of HBPU/PBS compositeimproves; the tensile strength of the composite increases withincreasing diol carbon chain length, but the elongation at break withthe hyperbranched urethane end groups of molecular carbon chainlength rising, first increases and then decreases.(3) HBPU/Talc/PBS ternary composite is obtained adding Talc asthe third component. The influence of adding method and amount ofTalc on the composite is discussed. The thermal property andmechanical performance of HBPU/Talc/PBS composites are tested byTG and universal testing machine. SEM(Scanning electron microscope)is also used to investigate the morphology of the composite tensilefracture. The results show that, the composite with Talc and HBPUpre-blending is better than the one with3components simultaneouslyblending. With Talc content increasing, the thermal performance andtensile strength of the composite increases, while the elongation atbreak of the composite decreases. In the composite with Talc andHBPU pre-blending, Talc particles distribute more uniformly andmuch better in PBS matrix than in the3components blending.(4) I～IV generation HBPE(Hyperbranched polyester) are synthe-tised by TMP(Trimethylolpropane) and DMPA(Dimethylolpropionic acid). The structures of different generations of HBPE are tested byNMR(Nuclear magnetic resonance) and IR. HBPE/PBS composites areobtained with different generations of HBPE. The thermal propertyand mechanical performance of the composite are tested by TG anduniversal testing machine. The alkaline degradation of HBPE/PBScomposites is carried out in pH=9,11,13solution. The results showthat, with the increase of HBPE generation, the thermal performanceand the mechanical properties of HBPE/PBS composite increase.