The Preparation And Performance Research Of PA1212and PA1012Toughening Composite Materials

PA1212and PA1012, two nylon species with long carbon chain, have beenwidely used in aerospace, construction, transportation, equipment manufacture and soon. Owing to the limited toughness, there is rare application of PA1212and PA1012in the manufacture of brake and oil hoses for automobile. In order to broaden theirapplication area, toughness-improved PA1212and PA1012fabricated by meltblending are reported in this dissertation. And the main study work is listed below:(1) TPAE, as a toughening agent, was blended with PA1212to preparePA1212/TPAE composite materials. The effect of the kinds of TPAE, the additionamount on the physical and mechanical properties of the composites was studied. Thetoughening mechanism of TPAE was investigated by means of the SEM observationof the cross section morphology. The results show that5k+ED2003is a bettertoughening agent among all the TPAE discussed here. The optimum addition amountof5k+ED2003is60%. At this moment, the elongation at break of the compositeincreases by150%and the notched impact strength is about2.5times of pure PA1212while the retention rate of its tensile strength is still over95%. SEM observationdemonstrates that the toughening mechanism is mainly crazing with shear yielding.(2) TPAE, as a compatibilizaters, was used to prepare PA1212/spandex/TPAEcomposites. The relationship between spandex/TPAE (the ratio and the content) andthe composites’ properties (the mechanical properties and melt crystallizationbehavior) was discussed. When ωspandex∶ωTPAE=3∶1and their content is30%, thecomposite possesses the optimal property. Its elongation at break increases by about40%, and the sample is unbreakable in the notched impact test at room temperature,while a slightly decline is noticed in its tensile strength.(3) PA1012/TPU/TPAE composite materials were prepared. The influence of thekinds and the addition amount of TPU, TPAE, and TPAE block on properties of thecomposite was investigated. When the content of E85is40%and the content ofTPAE is5%，composite with optimal properties is achieved. Its elongation at breakincrease by50%and the sample is also unbreakable in the notched impact test at room temperature. SEM images show that bicontinuous structure is constructed insideafter the addition of three-block-TPAE.Through the study above, the toughness of the modified PA1212and PA1012has been substantively improved. Furthermore, the modifying method is economicand convenient, which has the application prospects in the manufacturing of brakeand oil hoses used in automobile.