共查询到19条相似文献,搜索用时 93 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
《塑料工业》2017,(1)
采用挤出方式分别制备尼龙6/氯化钙(PA6/Ca Cl_2)、尼龙6/氯化钙/玻璃纤维(PA6/Ca Cl_2/GF)复合材料。利用差示扫描量热仪(DSC)研究了氯化钙和玻璃纤维对两种复合材料非等温结晶行为的影响,并用Jeziorny法、Mo法对复合材料结晶动力学进行研究。结果表明,Ca Cl_2的络合作用使PA6/Ca Cl_2复合材料起始结晶温度、结晶速率降低;而GF提高了PA6/Ca Cl_2结晶的起始温度,减小其总结晶时间,对于PA6/Ca Cl_2/GF复合材料,GF起到了成核作用。X射线衍射仪(XRD)研究表明,与金属离子诱导PA6生成α晶型不同,GF诱导其生成γ晶型。 相似文献
9.
10.
铸型PA 6/TiO2纳米复合材料的非等温结晶行为 总被引:3,自引:0,他引:3
采用差示扫描量热法(DSC)研究了铸型聚酰胺(PA)6/TiO2纳米复合材料在不同冷却速率下的非等温结晶行为,并用Jeziomy法、Ozawa法和Mo法对DSC测定结果进行了处理。结果表明:纳米TiO2对铸型PA6起到异相成核的作用,提高了铸型PA6的结晶速率和结晶峰温,缩短了半结晶时间。3种方法对比后发现:Ozawa法不适用于铸型PA6及其纳米复合材料非等温结晶动力学的处理,Jeziomy法基本适合,而Mo法最适合。采用Kissinger法计算出铸型PA6及其TiO2纳米复合材料的结晶活化能,发现纳米粒子提高了铸型PA6的结晶活化能.说明纳米TiO2阻碍了铸型PA6的分子链在结晶时的运动。 相似文献
11.
基于利福平结晶反应机制,考察反应体系的溶媒配比对利福平结晶反应的影响,并通过对比静态结晶与动态结晶结果,来确定利福平结晶反应体现的最佳反应条件。 相似文献
12.
用DSC(差示扫描量热法)研究了3种聚乙烯(PE)管材专用料在等温和非等温条件下的熔融、结晶行为。结果表明所研究的PE管材专用料的结晶度比较低,其等温和非等温结晶过程都是分2段进行的,二次结晶的现象比较明显。非等温结晶的结果用莫志深的方法处理可以得到较好的线性关系。3种PE管材专用料的结晶度以及结晶难易程度并不完全相同,其中PE80等级的聚乙烯管材专用料的结晶比PE100等级的困难。 相似文献
13.
Jun-wei Li 《Polymer-Plastics Technology and Engineering》2013,52(12):1204-1208
The Poly(vinylidene fluoride)/Hollow glass microspheres(PVDF/HGMs) composites were prepared by the method of solution blending. The non-isothermal crystallization of the PVDF and its composites were investigated with a differential scanning calorimeter (DSC). The results showed that the crystallization peaks shifted to a lower temperature and became wider with an increasing cooling rate. The HGMs caused to increase in crystallization temperature and initial crystallization temperature. In addition, the Jeziorny and the Mo methods were used to analyze the non-isothermal crystallization kinetics. The results showed that the crystallization rate rose with the cooling rate rising, however, the HGMs decreased the crystallization rates of the PVDF. 相似文献
14.
Melting behavior, nonisothermal crystallization and isothermal crystallization kinetics of polypropylene (PP) with metallocene‐catalyzed linear low density polyethylene (mLLDPE) were studied by differential scanning calorimetry (DSC). The results show that PP and mLLDPE were partially miscible. The Avrami analysis was applied to analyze the nonisothermal and isothermal crystallization kinetics of the blends, the Mo Z.S. method was used to take a comparison in nonisothermal kinetics. Values of Avrami exponent indicate the crystallization nucleations of both pure PP and PP in the blends were heterogeneous, the growth of spherulites is tridimensional and the spherulites in the blends were more perfect than that in pure PP. The crystallization activation energy was estimated by Kissinger method and Arrhenius equation and the two methods draw similar results. The mLLDPE increased the crystallization rate of PP in nonisothermal crystallization process and decreased it in isothermal process. The results from nonisothermal crystallization and isothermal crystallization kinetics were not consistent because the two processes were completely different. Addition of minor mLLDPE phase favors to increase the overall crystallinity of PP, showing the mLLDPE entered the PP crystals. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
15.
采用差示扫描量热仪研究了超高相对分子质量聚乙烯(PE-UHMW)对高密度聚乙烯(PE-HD)非等温结晶行为的影响。通过Jeziorny法和莫志深法研究了PE-UHMW/PE-HD共混物的非等温结晶动力学,并利用Kissinger方程和Takhor法计算了体系的非等温结晶活化能。结果表明,PE-UHMW是PE-HD的一种有效成核剂,提供了更多的活化晶核,起到了异相成核的作用;添加PE-UHMW后,PE-HD的结晶起始温度(To)、结晶峰值温度(Tp)和结晶速率均提高;当PE-UHMW含量为10 %(质量分数,下同)时,共混物结晶的活化能最小,结晶速率最大。 相似文献
16.
Xiang-Feng Wu Yong-Ke Zhao Ze-Hua Zhao Yang Sun Han Zhang Mai-Tuo Yu 《Polymer-Plastics Technology and Engineering》2017,56(5):556-562
The crystallization behaviors of graphene oxide–carbon nanotube hybrids/polyamide 66 composites were characterized by using differential scanning calorimetry. The results of nonisothermal crystallization showed that the halftime of crystallization and crystallization enthalpy increased with an increase in filler loading. The results of isothermal crystallization showed that the halftime of crystallization was affected not only by the filler loading but also the crystallization temperature. Moreover, it decreased with an increase in filler loading at 243°C, while decreased first and then increased at 245 or 247°C. In addition, when the filler loading was 0.6?wt%, it reached the minimum value. This was the same as the isothermal crystallization activation energy. 相似文献
17.
18.
For some polymers such as PTFE, the crystallization is so rapid that it is difficult to observe isothermal crystallization by differential scanning calorimetry (DSC). In this investigation, first, isothermal crystallization kinetics of PTFE was followed by DSC and the results were analyzed by the Avrami method, which showed that PTFE crystallizes one‐dimensionally from preexisting nuclei, presumably impurities. Furthermore, the crystallization activation energy, the equilibrium melting point, and the nucleation rate parameter Kg were calculated in the isothermal crystallization. Second, nonisothermal crystallization was also studied and the result was in accordance with the results of isothermal crystallization. Then, the Kissinger method was used to investigate the activation energy of PTFE in the nonisothermal crystallization. Third, the effect of glass fiber (used as filling) was investigated on crystallization of PTFE matrix. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 990–996, 2002 相似文献
19.
通过熔融共混法制备了尼龙11/碳化硅(PA11/SiC)复合材料,利用差示扫描量热仪(DSC)研究了该复合材料的非等温结晶过程,且采用Avrami方程修正的Jeziorny法和Mo法对其非等温结晶动力学进行了研究,并计算得到相关非等温结晶动力学参数。结果表明:Jeziorny法和Mo法都适用于处理PA11及PA11/SiC复合材料的非等温结晶过程,其分析结果均显示,SiC的加入影响了PA11复合材料的非等温结晶行为,少量(1%)SiC的加入促进了PA11复合材料的成核及晶体生长,提高了结晶速率;由Jeziorny法可知,PA11及其复合材料的非等温过程可分为初期结晶和二次结晶两个阶段,在二次结晶阶段,结晶方式为一维线性、二维盘状和三维球晶生长并存。 相似文献