The Effect Of The Acid Corroded Glass Fiber (GF) On The Interfacial Crystallization In Isotactic Polypropylene (iPP) Matrix Composite

For the fibre-reinforced polymer composites, its mechanical performance depends not only on the properties of the fibres and polymer matrix but also on the interfacial morphology. Interfacial morphology of the composites is always one of the hot issues in the field of polymer matrix composites. However, the poor compatibility between GF and iPP directly weakens the interfacial strenth of GF/iPP composite. At present, the enhanced interfacial strength of GF/iPP composites is mainly through the surface treatment of GF, matrix modification, and improvment of processing methods, etc.In this work, the composites were prepared by introducing the acid corroded GF into iPP matrix. Under isothermal condiditons, the effects of the acid corroded GF on interfacial morphology were studied by POM, DSC and 2D-WAXD, as well as the influence on crystalline morphology of injection molded parts. The main content is summarized as follows:(1) The GF were first acid corroded for different times. And then, the interfacial morphology of isothermally (130℃) crystallized GF/iPP composite was studied by POM. It has been found that the GF corroded for 4 h exhibits unusual nucleating ability, i.e., to induce novel banded nuclei in the early stage of the crystallization, and thenβ-transcrystallinity can be developed from these nuclei finally.(2) The morphology of isothermally crystallized at 142℃shows that GF corroded by acid for 4 h has nucleating duality towards iPP matrix, namely that it has bothβnucleation ability and a nucleation ability.(3) 4-GF/iPP composites crystallized isothermally at different temperaturer showed that crystallization temperature has a great impact on the growth rate of transcrystalline layer and spherulites in the matrix. In addition, considering the uneven distribution of iPP nuclei induced by GF, it is speculated that the surface roughness of corroded GF is somewhat different along the fiber axis.(4) Crystal morphology of the injection molded neat iPP and GF/iPP composites were studied by POM, DSC and 2D-WAXD. It is concluded that 4-GF still presentβ nucleation ability towards iPP in the injection molded part.