The MC nylon 6/ZnO nanocomposite was prepared by using the in-situ polymerizing reaction, and its isothermal crystallization behavior was studied by the differential scanning calorimetry(DSC). The results show that the crystallization rate of both MC

nylon 6 and MC nylon 6/ZnO nanocomposite are controlled by the nucleating process at 188 ℃ to 196 ℃. As compared to MC nylon 6, the crystallization rate G of MC nylon 6/ZnO nanocomposite increases 0.1~0.3 min-1. It is found that the increase of the crystallization rate of MC nylon 6 due to the nano-sized ZnO was used as the heterophase crystal nucleating agents. For both MC nylon 6 and MC nylon 6/ZnO nanocomposite, with increasing the crystallization temperature, the crystallization rate G and its constant k is decreased, the time t1/2 of the half crystallization and that tmax of the maximum crystallization rate is shortened. However, for comparison with MC nylon 6, the decrease content is more obvious for MC nylon 6/ZnO nanocomposite.

A High performance gel permeation chromatography(GPC),evaporative light-scattering detector(ELSD) method were applied to determine the relative molecular weight and its distribution of vacuum gas oil(VGO),adopting linear calibration with kown relative molecular weight calibration standard and complicated mathematics operation. Also the precision of the technique was evaluated and the relative molecular weight between GPC and VPO was compared. The results show that the relative error is less than 1%, comparison with traditional method of VPO the analysical rate is promoted five times, the sample oils less to 1/10. The technique is accurate, fast and high level of automatic operation. 