Characterization Of The 1212 Structure And Properties Of The Oil And Fermented Nylon

The crystal structure of petroleum fermentation nylon1212 (nylon!212) was studied by means of X-ray diffraction. The results show that the nylon!212 crystallizes in the triclinic system, with lattice dimensions: a=0.490nm, b= 0.520 nm, c=3.25 nm, a = 50, p =77, y =64.5, and the unit cell contains one monomeric unit and the space group is P1. From above results, the unit cell density Pc was calculated to be 1.126g/ cm3. The crystal transitions of nylon!212 crystallized and drawn at different temperature with different drawing ratios (? were investigated by WAXD. The form of nylon1212 would not change when nylon!212 drawn at the same temperature with different drawing ratios. The a -form of nylon!212 could be transformed from the P form with the drawing temperature increasing. The a -form of nylon!212 could be transformed from the 3 form when nylon1212 crystallized from low temperature to high temperature. And the property of nylon1212 was also investigated by Fourier Transform infrared (FTIR) spectroscopy. The band assignments of nylon!212 were determined by FTIR. From infrared spectroscopy, we confirmed that the a -form of nylon 1212 could be transformed from the P form with the crystalline temperature increasing. The bands at 686 cm-1,1188 cm-1,1419 cm-1are crystalline bands, and the bands at 961cm-1,1079 cm-1are noncrystalline bands by the method of density-IR. The degree of crystallinity was calculated by WAXD, density and IR method, and the results were identical.The glass transition temperature (Tg), equilibrium melting point temperature and equilibrium heat of fusion of nylon!212 were determined by means of differential scanning calorimetry (DSC) and density measurement techniques. Tg of nylon1212 is to be 43 C by DSC. The equilibrium melting point temperature of nylon1212 is to be 188.2C from the Hoffman's method. The equilibrium heat of fusion of nylon1212 is estimated to be 120.87J/g plotting Hm of specimens with different crystallinity against their corresponding specific volumes Vsp. The size and position of the endothermic peaks were strongly related to crystallized temperature. In the DSC heating curves of isothermally melt crystallized from cold quenching, Peak I, II were imperfect crystals, peak III was the more perfect crystal. In melting endotherms of nylon 1212, recorded at the heating rate of 10C/min, after isothermal crystallization, Peak I is to be microcrystallite formation in the boundary layer between the largercrystallites. Peak II is the major crystal in the isothermal crystallization process. Peak III is the ultimate metastable crystal in given condition. The TG results of nylon 1212 indicate that the thermal degradation process of nylon1212 is one-step reaction. The activation energy of the solid-state process was determined using Kissinger and Flynn - Wall - Ozawa methods, resulting to be 227.5 ~ 228.2KJ/mol. Analysis of experimental results suggests the actual reaction mechanisms nylon!212 of is Deceleration type.Isothermal and nonisothermal crystallization kinetics of nylon!212 were investigated by DSC. The commonly used Avrami equation and that modified by Jeziorny were used, respectively, to fit the primary stage of isothermal and nonisothermal crystallizations of nylon 1212. The Avrami exponent n was evaluated, and was found to be in the range of 1.56 to 2.03 for isothermal crystallization, and of 2.38 to 3.05 for nonisothermal crystallization. The activation energies (AE) were determined to be 284.5KJ/mol and 102.63KJ/mol, respectively, for the isothermal and nonisothermal crystallization processes by the Arrhenius' and the Kissinger's methods.The morphology of melting-crystallization nylon1212 was observed by PLM. There are eight kinds of spherulite as crystalline temperature changed.The dynamic mechanical properties of nylon1212 were investigated by dynamic mechanical analysis (DMA). The peak at 65C-35C and - 116C were to be a relaxation, 3 relaxation and Y relaxation of nylon1212, respectively.Rheological properties of Nylonl212 have been studied by mean...