Study On The Blending Modification PTT/TPU And Preparation Of Blending Fiber

PTT(poly propylene glycol terephthalate) fiber is getting more and more widely used in clothing, carpets, and other fields because of excellent general performance, however, the cost of PTT is too high, and it is not mass production in China, lead to can not meet domestic demand. In this paper, PTT was modified by TPU by blending modification, mainly study the compatibility and rheology of the blending system, as well as blending fiber preparation and structure performance research.First, the compatibility of PTT/TPU was studied by theoretical pretical, solubility parameter method, polymer enthalpy reform, than strong viscosity and viscosity method, the results show that PTT/TPU blend system was partly compatible. At the same time, in this paper, DSC, FTIR, UV, SEM were used to research the compatibility of PTT/TPU. DSC results show that the blending system with only one obvious Tg peak, which; FTIR analysis with the method of the surface reflection, the results in figure without TPU characteristic peak, which show that PTT/TPU polymer system is partially compatible; UV curve shows that the transparency of blend membrane less than that of PTT membrane,but when TPU content continues to increase, the transparency of blend membranes is improved; SEM photos showed that PTT/TPU blend system, with the increase of TPU content of two phase separation system has certain improvement.Secondly, the rheological properties of the PTT, TPU and PTT/TPU blend were studied, the results shows that PTT, TPU and PTT/TPU blend logistics are pseudoplastic fluid, PTT had higher non-newtonian index than TPU, shows that PTT non-newtonianism more weak, which indicated PTT was more sensitive to shearing rate than TPU; The rheological properties of PTT/TPU blend was studied, which shows that the non-newtonian index is more and more smaller with the increase of the content of TPU, so the blend logistics become more and more sensitive to shearing rate, in the processing process we can appropriately adjust the shear rate and temperature. The mechanical properties of blend system was studied shows that the elastic modulus of the blend reduced, elongation at break increased with the increase of content of TPU, the addition of TPU can toughen PTT.Finally, blend fiber based on different proportions of the PTT/TPU were prepared by melt spinning, the mechanical properties and thermal properties was studied, the elastic modulus decreases slightly with the increase of draw ratio, and the PTT fiber had obvious yield point after hot stretch, elongation at break increased; The mechanical properties of the blend system analysis shows that the elastic modulus decreased, elongation at break increased, fracture strength drop with the increase of content of TPU, the addition of TPU can toughen PTT, made the blend materials become more soft and tough; Thermal analysis for fiber shows that crystallinity reduced and reduced crystalline perfection with the increase of the content of TPU, because the addition of TPU destroyed the regularity of the molecular chain, lowered the molecular inter-atomic forces. The DSC analysis shows that the crystallinity decreeased with the increase of TPU content. The crystallinity increase of the fiber after thermal stretch, because the tensile lead to molecular chain orientation induced crystallization.