Poly (Vinyl Alcohol)/Hydrotalcite Blending System Research And Fiber Preparation

Polymer/inorganic blend is one of the most important classes of synthetic engineering materials. It can be transformed into a kind of new materials possessing advantages of both organic materials, such as light weight, flexibility, and good moldability, and inorganic materials, such as high strength, heat stability, and chemical resistance. The hydrotalcite (HT) is one kind of anion layered inorganic materials. HT has much merits, such as simple preparation, product purity, low cost, its components and charge density can be adjustable et al. When blending with the polymer, HT can also display heat-resisting, modified functions like as montmorillonite clay. It has a broad prospect of application.In this article we use solution intercalated to prepare PVA/HT blend solution, and prepare PVA/HT blend fibers by gel-spinning and electrospinning, then do some performance testing and structure characterization for blend fibers. This thesis contains three parts:First, under ultrasonic condition, HT was added to dimethylsulfoxide (DMSO) solution and rapidly stirred in order to cause HT to disperse evenly in DMSO. Then PVA was added to the solution to prepare the PVA/HT blend spinning solution, and finally the PVA/HT blend fibers were prepared by gel-spinning. The surface morphology and dispersion of HT in PVA/HT blend fibers were observed by SEM. FT-IR test showed that between HT and PVA had obvious hydrogen bond function and few HT didn't undermine the crystallization of PVA. XRD test indicated that some of the molecular chains of PVA inserted into the HT and increased the layer spacing.Second, the as-spun fibers were stretched by heating in twice, influences of pre-stretch and HT content to the mechanical properties of blend fibers were respectively studied, and the effect of HT contend to the draw ratio of blend fibers were discussed. The morphology of blend fibers which after over-draw were observed by SEM, the thermal property of PVA/HT blend fibers were investigated by TG-DTG, and also we mad some mechanical test for the blend fibers. The result showed that adding appropriate HT can improve the strength of PVA fibers effectively. With the increasing of HT, the elongation and the maximum draw ratio of the blend fibers declined. Thermal analysis test showed that HT can increase the thermal properties of PVA effectively. Observing by SEM, we found that with the increase of the content of HT, the surface of blend fibers defect easily.Third, HT was treated by sodium dodecyl benzene sulfonate(SDBS) in aqueous solution, and the PVA/t-HT blend spinning solution was prepared by solution intercalated, and then PVA/t-HT blend fibers were prepared by electrospinning. SEM test showed that HT which was treated by SDBS has good dispersion in PVA. In weak acid condition, PVA/t-HT blend solution has the best spinnablity. DTA test indicated that with the increase of t-HT, the heat-resistant of blend fibers are enhanced. Mechanical test results showed that adding appropriate t-HT can improve tensile strength and Young modulus of PVA matrix effectively.