Study On The Development And Application Of Pet Fiber Modified By Iso-Sorbide

Polyester fibers may be the biggest consumption variety in Oil resources. As renewable biological resources, sorbitol manufacturing costs is very low. Sorbitol’s price is only one-third of ethylene glycol’s. there are abundant raw sorbitol in the northeast of China. This paper explored the possibility of the use of iso-sorbide as the raw materials for polyester fibers industry in order to explore the ways of the sustainable development of China’s polyester fibers industry and provide project basis for revitalizing the Northeast Industry. First of all, this paper discussed the preparation and conversion rate of iso-sorbide. Then, this research synthesized polyester (PESIT) by copolymerizing iso-sorbide, terephthalate and ethylene glycol. On the basis of the success of the 1L copolymerization in the laboratory, this study completed 30L-10kg-class pilot copolymerization experiment. Finally, with the 10kg-class from the PESIT, the high-speed spinning test was completed on the existing polyester POY spinning equipment. The spinning process of the PESIT, the spinnability of fibers and the performance of the PESIT fibers were preliminarily evaluated.Sorbitol to iso-sorbide preparation is a dehydration change. After testing several methods, ultimately, industrialization treatment using oil of vitriol as catalyst was used to prepare iso-sorbide. Through analyses of the MS, IR, UV and NMR, the product dehydrated was identified as iso-sorbide, at the same time, the maximum yield of iso-sorbide was identified as 30%.This research discussed the polymerization process of the PESIT in which iso-sorbide content was 3%, 5%, 10% and 20%. The copolymerization structure of the PESIT was confirmed by NMR and FT-IR; thermal property of the PESIT was analyzed by DSC and TG; viscosity analysis was finished by intrinsic viscosity method.For importing iso-sorbide, the analysis of DSC illustrated that the improve performance by copolymerization can descend the flexibility of macromolecular chain of co-polyester as well as increasing the temperature of glass transition and crystallization. On the contrary, the analysis of TG illustrated that with the increasing of iso-sorbide structural units, thermal decomposition temperature decreased, which was due to the easy oxidation of ether bond in iso-sorbide.The testing results of X-ray diffraction, sound-velocity-oriented instrument, electronic tensile testing machine and scanning electron microscope (SEM) were as follows. Degree of crystallization and degree of orientation of the PESIT fibers were lower than those of the PET fibers, and decreased with concentration increasing; mechanical analysis of the PESIT fibers showed that: breaking strength and breaking elongation had risen markedly compared with conventional PET, which was consistent with low end breakage rate observed in the process of spinning, so the PESIT slices had better spinnability than the PET; uptake rate test showed that: the dyeing rate of the PESIT fibers improved slightly compared with the PET fibers.This paper included four parts of experiment: the preparation of iso-sorbide, the polymerization of the PESIT, the spinning of the PESIT fibers and the testing of the fiber performance. The result of whole experiment indicated that we can take use of existing polymerizing equipment and spinning equipment to prepare the PESIT fibers; the PESIT fibers had better spinnability than the PET fibers and similar properties with the PET fibers; as long as iso-sorbide can achieve large-scale industrialization and lower manufacturing costs, the PESIT fibers will be one of the potential alternative varieties of the PET fibers; iso-sorbide in the copolymer fibers content was up to 20 percent, thus, the development of iso-sorbide was a possible avenue to reduce our dependence on oil resources; the bottleneck of this industrial chain was that there was low yield of the existing process using sorbitol to prepare iso-sorbide, therefore, to find a high conversion rate of iso-sorbide manufacturing process may also be one of sustainable development approaches of China’s polyester fibers industry.