Preparation And Studies Of PA11/PVC Polymer Blends

The research of multicomponent polymers system plays an important role in the basic theory of polymer physical chemistry and polymer materials, as well as the design of novel specially applied materials. Enlightened by reactive compatibilization and intermolecular specific interactions compatibilization, this thesis applies two anhydrides to compatibilise PA11/PVC multicomponent polymers. The structures and the properties of polymer blends were studied by SEM, DMA, IR, 13C NMR, DSC, XRD and so on, various results implied that the PA11/PVC blends were successfully compatibilized.The effect of SMA content on the mechanical properties indicates an optimal SMA content of 8 wt%, whereas that of the EVA-g-MAH at about 15 wt%, showing that the CMC of EVA-g-MAH is higher than that of SMA. For the two compatibilizer compatibilised systems, the tensile properties decreased slightly with the increased PVC content, impact properties maintain at PA11 standard before 50 wt% PVC attendance and decrease dramatically after 50 wt% PVC attendance. Elongation at break decreases and tensile moduli increases with the PVC increase. Because the low modulus of EVA-g-MAH, its compatibilized blends have lower modul comparing with SMA compatibilized system.FT-IR and 13C NMR tests demonstrate that the maleic anhydride group of the compatibilizer in-suit reacted with the amine end of PA11 at the interface. The melting parameters of the DSC testing further indicated the grafting reaction. On the basis of various literatures and our results and discuss, a simply model of the compatibilizing mechanism of the two reactive anhydrides can be summarized as the following: A/C/B type multicomponent polymers system in-suit reacts to A/A-g-C/B type, here intermolecular specific interactions exit between C and B.The glass transition temperature of PAH and PVC components in the blends decreased, comparing with the virginal PAH and PVC. The presence of compatibilizer and PVC molecular chain destroyed the formation of intermolecular hydrogen bonds which would multiply exited in virginal PAH, leading to decreased intermolecular interactions of PA 11 component and the consequent lowed glass transition temperature. The morphology of PA11/PVC polymer blends indicated thatPA 11 exited as the continuous phase and PVC as the dispersed phase in the region of PA11/PVC ratio from 1/3 to 3/1. The increased PVC content in the blends leads to the increase and non-uniform of PVC domain size.The study of PA 11 crystallization behavior of PA11/PVC blends indicates that: PA11 component occurs crystalline transition from the original unstable high Tm δ' form to stable low Tm a form. The functions of SMA, EVA-g-MAH and the other PVC component reveal that the crystallization ability of PA11 was destroyed, consequently lowered crystallinity and melting point of PA 11 component. Although the diffraction peaks decrease with increasing compatibilizer, there is an obvious difference in the effect of SMA and EVA-g-MAH on PA11 crystallization behavior. Specifically, the lower (010, 110) peak developed to be higher than the once higher (100) peak with the increasing EVA-g-MAH content, whereas the reversed trend occurs in SMA compatibilized blend.