Preparation And Structural Properties Of Bio-based Long Carbon Chain Nylon Fibers

At present, the main production of nylon fiber used in the market is the nylon 6 and nylon 66. The production is mainly based on the petroleum process. Along with the further development of the society, the production of the traditional nylon fiber has led to a growing burden to the environment. Bio-based material is a kind of renewable resources for many high performance materials with single source and it represents the future direction of nylon development. The bio-based long carbon chain nylon polymer is synthesized by bio-based binary acid and bio-based diamine, which greatly reduced the emissions of carbon in the production process and had good environmental benefits. Now there are fewer researches about bio-based long carbon chain nylon fibers at home and abroad, especially the research of bio-based long carbon chain nylon 5X has not been reported. The structure of the subject of bio-based long carbon chain nylon polymers were studied by using melt spinning method, and the structure and properties of the fibers and the corresponding fabrics style has been systematically studied. It is expected that the paper has a good reference guide for the research testing and subsequent mass production of bio-based long carbon chain nylon fibers. The main contents and results of the research are as follows.(1) The structure of the polymer was characterized by 1H NMR, IR, and elemental analysis. The results showed that the structure of the bio-based long carbon chain nylon is consistent with the theory.(2) The thermal properties of PA510、 PA512、 PA612 were tested, which used to provide reference for the setting of the melt spinning process parameters. The results showed that the melting point of long carbon chain PA510, PA512 and PA612 was about 220℃, and the crystallization temperature range from 149 ℃ to 177 ℃ and the thermal decomposition temperature is 410℃. This suggests that long carbon chain nylon has a wide range of processing and can meet the spinning requirements.(3) DSC used to test the non-isothermal crystallization kinetics of PA510, PA512 and PA612 polymers and POM was used to observe the growth of grain in non-isothermal crystallization conditions. The results show that there is heterogeneous nucleation during crystallization and the growth is three-dimensional mode.(4) The three kinds of nylon fibers were prepared by melt spinning and the spinning temperature range from 265℃ to 285℃, the spinning speed is 800m/min. The fibers’ aggregation structure were studied by XRD technique. The mechanical properties of the fibers at different draw ratio were tested by using the yarn strength and elongation tester, the results showed that the fracture strength were 4.3~6.9c N/dtex, the initial modulus was 33~42c N/dtex, the elastic recovery rates were above 90% under 10% elongation, the three kinds of nylon fibers had good mechanical properties and elastic recovery properties. In addition, their boiling water shrinkage rates were 12.9% to 17.4% and the moisture regain were 1.6~2.1%. The hydrophilic properties of PA5 X fibers were better than PA612.(5) The fabric style of PA510, PA512, PA612 fabric were studied by using KES fabric style instrument. The basic style and comprehensive style of the thick coat fabrics were calculated. Three kinds of fabric stiffness values were greater than 5, the fullness value of PA56 was above 5 and the others were close to 5, slippery waxy values were 4.1 and the integrated style value was about 3.The results showed that the bio-based long carbon chain PA510, PA512 and PA612 fabric can used to make cloths.