尼龙6/蒙脱土纳米复合材料非等温结晶动力学和透明性研究

将有机化的蒙脱土与尼龙6(PA6)在Haake共混机中共混,制备出尼龙6/蒙脱土纳米复合材料(PA6N);对尼龙6/蒙脱土纳米复合材料和纯尼龙6分别进行差示扫描量热法非等温结晶试验,以了解蒙脱土在尼龙6/蒙脱土纳米复合材料中的成核作用、扩大尼龙6在包装领域的应用范围.与此同时,采用偏光显微镜测定了样品的结晶形态;采用紫...     

聚丙烯/纳米蒙脱土复合材料的结晶动力学研究

采用热分析方法，研究了聚丙烯／纳米蒙脱土复合材料（PP／CLAY）的等温结晶行为，并分别用Avrami方程和赵志英方法对所得数据进行了分析，研究结果表明，纳米蒙脱土微粒对聚丙烯等温和非等温结晶行为均有不同程度的影响，可提高聚丙烯的结晶速率并改善结晶结构。     

聚丙烯/蒙脱土纳米复合材料非等温结晶动力学的研究

用熔融插层法制备聚丙烯 蒙脱土纳米复合材料 ,用DSC手段研究了其非等温结晶行为 ,并与聚丙烯进行了对比 .对所得数据分别用修正Avrami方程的Jeziorny法、Ozawa法和Mo法进行处理 .结果表明 ,用Jeziorny法和Mo法处理非等温结晶过程比较理想 ,而用Ozawa法处理则不太适用 .用Jeziorny法求出的参数Zc和n随冷却速率的增加而增加 ,但复合材料的Zc 和n略大于聚丙烯的Zc 和n ,用Mo法求出的参数F(T)随结晶度的增加而略有增加 ,a几乎未变 ,复合材料的F(T)略小于聚丙烯的F(T) ,复合材料的a约为 1.40略大于聚丙烯的a(其值约为 1.0 4) .按Kissinger方法计算出聚丙烯及聚丙烯 蒙脱土纳米复合材料的结晶活化能分别为 189.37kJ mol,15 5 .6 9kJ mol,说明有机蒙脱土的加入 ,降低了聚丙烯的结晶活化能 ,起到了异相成核的作用     

尼龙6/蒙脱土纳米复合材料的等温结晶动力学研究

用ＤＳＣ法研究了熔体插层制备的尼龙６／蒙脱土纳米复合材料的等温结晶行为．结果表明,加入少量的蒙脱土可明显提高尼龙６的结晶速率,降低球晶径向生长的单位面积表面自由能．从Ａｖｒａｍｉ方程和Ｈｏｆｍａｎ理论出发,得出蒙脱土纳米粒子的存在可明显改变尼龙６的结晶行为     

聚甲醛/蒙脱土纳米复合材料非等温结晶动力学研究

聚甲醛/蒙脱土纳米复合材料非等温结晶动力学研究     

聚甲醛/蒙脱土纳米复合材料非等温结晶动力学研究

聚甲醛/蒙脱土纳米复合材料非等温结晶动力学研究     

蒙脱土对尼龙66熔融与结晶行为的影响

通过DSC方法研究了蒙脱土对尼龙66熔融与结晶行为的影响,探讨了蒙脱土对尼龙66结晶的成核作用。发现有机蒙脱土使尼龙66的熔融峰温度Tm提高5.3℃,使结晶峰温度提高13－24℃,二次熔融多产生双重熔融峰,蒙脱土的加入有利于生成低温峰。     

β-羟基丁酸与β-羟基戊酸共聚物 (PHBV)/蒙脱土纳米复合材料的等温结晶动力学

用差热量热分析（DSC）方法研究了β－羟基丁酸与β－羟基戊酸共聚物（PHBV）／蒙脱土纳米复合材料的等温结晶行为。结果表明，PHBV的Avrami方程指数n、成核机理、结晶生长方式基本不受蒙脱土的影响，加入少量的蒙脱土可明显降低PHBV结晶成核自由能，使其结晶速率增大。     

聚丙烯/聚(丙烯-g-马来酸酐)/蒙脱土纳米复合材料结晶动力学研究

非等温结晶动力学;聚丙烯/聚(丙烯-g-马来酸酐)/蒙脱土纳米复合材料结晶动力学研究     

尼龙6/蒙脱土纳米复合材料的结晶行为

用广角Ｘ 射线衍射（ＷＡＸＤ）、差示扫描量热仪（ＤＳＣ）、小角激光散射（ＳＡＬＳ）等手段研究了尼龙６／蒙脱土纳米复合材料的结晶行为．结果表明分散在尼龙６基体中的蒙脱土纳米粒子起成核剂的作用．蒙脱土的表面改性增加了蒙脱土和尼龙６分子之间的界面粘接，它具有阻碍尼龙６结晶的作用，使结晶活化能增加     

可分散性纳米SiO2对尼龙66结晶行为的影响

可分散性纳米SiO2对尼龙66结晶行为的影响;纳米ＳｉＯ２;尼龙６６;结晶行为     

Effect of Electron Beam Irradiation on the Kinetics of Non-isothermal Crystallization of Nylon 66

The non-isothermal crystallization kinetics was studied by differential scanning calorimetric analysis on nylon 66 and e-beam irradiated nylon 66 at different cooling rates. The Modified Avrami equation, the Ozawa equation and the Combined Avrami-Ozawa equation were applied to study the kinetics of non-isothermal crystallization of nylon 66. The crystallization behavior of pristine nylon 66 polymer was compared with that of e-beam irradiated nylon 66 and observed that the kinetics of non-isothermal crystallization of nylon66 was affected largely upon e-beam irradiation. E-beam irradiation not only decreased the crystallization temperature of nylon 66, but influenced the mechanism of nucleation and crystal growth and reduced the overall crystallization rate of nylon 66 also. The crystallization activation energy calculated by the Kissinger method for irradiated nylon 66 was lower than that of pristine nylon 66.     

Multiple melting and crystallization of nylon‐66/montmorillonite nanocomposites

Nylon‐66 nanocomposites were prepared by melt‐compounding nylon‐66 with organically modified montmorillonite (MMT). The organic MMT layers were exfoliated in a nylon‐66 matrix as confirmed by wide‐angle X‐ray diffraction (WAXD) and transmission electron microscopy. The presence of MMT layers increased the crystallization temperature of nylon‐66 because of the heterogeneous nucleation of MMT. Multiple melting behavior was observed in the nylon‐66/MMT nanocomposites, and the MMT layers induced the formation of form II spherulites of nylon‐66. The crystallite sizes L₁₀₀ and L₀₁₀ of nylon‐66, determined by WAXD, decreased with an increasing MMT content. High‐temperature WAXD was performed to determine the Brill transition in the nylon‐66/MMT nanocomposites. Polarized optical microscopy demonstrated that the dimension of nylon‐66 spherulites decreased because of the effect of the MMT layers. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2861–2869, 2003     

Isothermal and nonisothermal crystallization kinetics of irradiated nylon 1212

The crystallization behavior of nylon 1212, irradiated at ⁶⁰Co γ‐rays (50 kGy), was studied by a rheometer, polarized optical microscopy (POM), and differential scanning calorimeter (DSC). The results showed that irradiated nylon 1212 samples exhibited abnormal crystallization behavior during the crystallization process: The Avrami exponent n was calculated and was found to be in the range from 2.06–2.41 for isothermal crystallization, and from 2.67–4.91 for nonisothermal crystallization; the spherulite morphology also changed largely by polarized optical microscopy (POM); the crystallization activation energy ΔE for isothermal and nonisothermal crystallization process of irradiated nylon 1212 are determined to be 57.4 kJ/mol and 78.65 kJ/mol, respectively, which are lower than that of nonirradiated nylon 1212. At the same time, a new method by a combination of the Avrami and Ozawa equations was successfully applied to analyze the noncrystallization process of irradiated nylon 1212. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2326–2333, 2005     

热历史对尼龙1212熔融行为的影响

利用DSC方法研究了不同热历史条件对尼龙1212熔融行为的影响.不同的热历史条件下,在DSC曲线上,观察到尼龙1212产生2个或3个熔融峰,依据聚合物结晶理论,对各峰的来源进行了分析.在160℃下不同温度退火120 min的尼龙1212样品DSC曲线上,低温结晶熔融峰主要由低温结晶形成的一些微晶体或者片晶熔融产生,其晶体完善程度较差,熔融峰值较低,峰面积较小;主熔融峰是由样品在淬火过程中形成的晶体和升温过程中低温结晶形成的晶体的熔融重结晶形成较为完善的晶体熔融所产生,熔融峰值较高,峰面积较大.在不同的升温速率条件下,熔融峰温度有所移动,表明不同升温速率条件下产生的熔融峰的结晶晶型是相同的.在不同结晶时间下结晶,延长结晶时间对较高完善程度晶体的生长有利.在不同温度下依次退火处理的样品,熔融产生两个附加峰,这两个附加峰的峰温都比它们相应的退火温度高,而峰高和峰面积随退火温度降低而减小.根据等温结晶结果,由Hoffman方法确定了尼龙1212的平衡熔融温度为202.8℃.     

Highly improved crystallization behavior of poly(L‐lactide) induced by a novel nucleating agent: substituted‐aryl phosphate salts

In this work, a novel nucleating agent (NA) based on substituted‐aryl phosphate salts was introduced into poly(L‐Lactide) (PLLA). The nonisothermal and isothermal crystallization behaviors of nucleated PLLA samples were investigated through differential scanning calorimetry (DSC), wide angle X‐ray diffraction, and polarized optical microscope (POM). Furthermore, the effect of annealing treatment on the cold crystallization behaviors of nucleated samples was also investigated. The results show that the crystallization of PLLA, whether for the melt crystallization (including nonisothermal and isothermal crystallization process) or for the cold crystallization (including the cold crystallization occurring during the DSC heating process and during the annealing process), is greatly dependent upon the content of NA. At relatively lower NA content (≤0.1 wt%), the nucleation effect of NA is inconspicuous, however, at higher NA content (≥0.2 wt%), it exhibits great nucleation effect for the crystallization of PLLA. Further results show that the double endothermic peak of PLLA depends on the temperature applied for the crystallization. Copyright © 2012 John Wiley & Sons, Ltd.     

聚丁二酸丁二醇酯的自成核结晶行为

利用差示扫描量热仪(DSC)研究了自成核对聚丁二酸丁二醇酯(PBS)的结晶行为的影响. 研究结果表明, PBS的有效自成核温度处理区间为118～120 ℃. PBS经自成核处理后结晶温度提高, 可以在100~118 ℃温度区间内迅速结晶. 同时, 研究了自成核处理后样品在100～104 ℃范围内的等温结晶行为、动力学过程及熔融行为. 结果表明, 随着等温结晶温度的升高, 结晶速率变慢, 熔融曲线出现多重熔融峰. Hoffman-Weeks方程分析结果表明, 自成核处理对PBS的平衡熔点没有影响. Avrami等温结晶动力学方程适合分析自成核处理样品的等温结晶动力学过程, 获得其动力学参数K与n, 其中n值偏大的原因在于自成核的样品结晶生长点增多. 根据Arrhenius方程, 计算获得PBS自成核处理后等温结晶活化能为-286 kJ/mol.