Study On Surface/Interfacial Properties Of Polyethersulfone Modified Polypropylene

Polypropylene(PP) is a kind of common thermoplastic resins,which have been used extensively used in various fields owing to its good performances.PP has some properties of good insulation,erosion-resistant,processing easily,wearing resistance etc;it has a lower price among the resins.However,PP has a poor impact strength at lower temperature and obvious shrinkage that limits PP to be used as an engineering plastic.Polyethersulfone(PES) is a amorphous thermoplastic with a high glass transition temperature of 230℃,it has some virtues such as dimension stability,resistance to high temperature aging in hot water,apyrous and radiation-proof.The modulus of elasticity of PES is slightly affected by high temperature. Some PES composites can be made,such as glass fiber and carbon fiber reinforcement composites.Nowadays,PES is already employed in multitude of applications in the fields of automotive and navigation,electrical and electronics fields and separation membrane industry.In this paper,PES modified PP system was investigated,mainly focus on the surface/ interfacial properties when two plastics were blended.The two polymer's surface dispersive free energy,Lewis acidic number and Lewis basic number were characterized by inverse gas chromatography(IGC).The Lewis acid-base interaction of two polymers was discussed with Lewis acid-base interaction theory.At last,the Lewis acid-base interaction parameter I_(sp)3 was obtained,the result suggests that PP/PES blends were Lewis base-base repulsion system.The Flory interaction parameter x₂₃ and interaction energy density B₂₃ were characterrized by IGC,the interactions between 16 probes and polymers at various temperatures were obtained.The interaction parameters x₂₃ and "a probe normalized interaction parameter" x₂₃ between PP and PES were calculated using the method of Huang by selecting the probe with littleâ–³_x effect.It was found that PP/PES has a poor compatibility,the SEM photos confirmed the result.The values of x₂₃ increase with contents of PES in PP matrix increase. For a given polymer blend,The values of x₂₃ increase with increasing temperature.The kinetics of nonisothermal crystallization of PP and PP containing PES were investigated by differential scanning calorimetry(DSC),mechanics properties of them were studied.The Avrami equation,Ozawa equation and Mo method were applied to the whole nonisothermal crystallization of PP and PP/PES blends.It was observed that the Avrami equation can effectively describe the beginning of crystallization;the Ozawa equation could successfully describe the nonisothermal crystallization process of PP and the end stage of the crystallization process for PP/PES blends.Mo method is successful in describing the nonisothermal process of PP and PP/PES blends.At last,the effective activation energy(â–³E) was determined through electing Kissinger method.The results showed that theâ–³E of PP is lower than those of PP/PES blends.The value ofâ–³E increases with the contents of PES in PP matrix increase, indicates that PES limited PP's nucleation ability and hampered the growth of PP spherulites.It maybe relates to the feature of rigid molecular chain of PES and the presence of PES in PP matrix.The results of mechanics of PP and PP/PES blends showed as follows:the tensile and izod impact strength of PP/PES blends were lower than those of neat PP,but the bending strength of PP/PES was slightly higher than that of PP,combining with the SEM photos,the reason may be the presence of PES in PP matrix was continuous fiber-like,works as reinforcement,so as to increase the bending strength.