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     

尼龙6/蒙脱土纳米复合材料的制备、结构与力学性能的研究

未经处理及经１１ 氨基酸处理的蒙脱土由于己内酰胺的引入而发生膨胀．己内酰氨可以在蒙脱土的硅酸盐片层间聚合，形成尼龙６／蒙脱土纳米复合材料．经１１ 氨基酸处理的蒙脱土和尼龙６分子间有很强的化学相互作用．与未经处理的蒙脱土相比，其所构成的纳米复合材料具有很好的力学性能．     

聚苯乙烯/蒙脱土熔融插层复合的研究

用熔融法制备了聚苯乙烯／蒙脱土插层复合材料，用Ｘ 射线衍射、ＤＳＣ等手段研究了复合材料的结构与性能．聚苯乙烯熔体不能插层于钠基蒙脱土中，但能插层于经有机化合物处理过的蒙脱土中．     

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     

丙烯酸树脂／蒙脱土纳米复合材料的制备研究

采用离子交换法,用十六烷基三甲基溴化铵对钠基蒙脱土(Na-MMT)进行改性制备了有机蒙脱土(OMMT).用丙烯酸(AA)、硫酸化蓖麻油、乳化剂OP-10、过硫酸钾为原料进行水溶液聚合制得丙烯酸树脂.将丙烯酸树脂与改性蒙脱土通过聚合插层制备了丙烯酸树脂/ 蒙脱土纳米复合材料.通过傅立叶变换红外(FTIR)和X-射线衍射 (XRD)等手段对复合材料的结构进行了表征,结果表明:丙烯酸树脂插层进入有机蒙脱土内可形成插层型或剥离型的纳米复合材料.蒙脱土含量及蒙脱土与丙烯酸树脂的反应温度、反应时间均对复合材料的剥离行为产生影响,在蒙脱土含量为树脂固含量的7%、温度为70℃、反应4h的条件下可得到完全剥离的纳米复合材料.     

静电自组装聚电解质/有机染料插层蒙脱土光致变色纳米复合膜

从构筑静电自组装聚电解质／有机染料插层蒙脱土光致变色纳米复合膜所必需 的基本纳米构件--有机染料插层蒙脱土光致变色纳米复合物的设计出发，制备了具有光致 变色功能的蒙脱土／阳离子偶氮染料（GTL）均插层纳米复合物现，插人蒙脱土层 间的GTL热稳定性大幅度提高．由于GTL在纳米受限空间的超分子有序结构共轭，使 偶氮基发生了高达91 nm的显著红移．使用该插层纳米复合物构件与阳离子聚电解 质（PDAC）通过静电自组装得到了生长均匀、排列规整有序的光致变色聚电解质／ 阳离子偶氮染料插层蒙脱土纳米复合膜.     

间规聚苯乙烯/尼龙6/磺化间规聚苯乙烯/蒙脱土纳米复合材料的研究

以磺化间规聚苯乙烯（SsPS)为增容剂，将间规聚苯乙烯（sPS)和尼龙6／改性蒙脱土纳米复合物（PA6－MTA）共混，得到综合性能优良的新型多组分聚合物／蒙脱土纳米复合材料（sPS/PA6/SsPS/MTA)。用DSC、DMA、WAXD及力学性能测试仪研究了纳米复合材料的结构与性能。TEM测定证明了蒙脱土在基体中的层厚分布为10－50nm。     

光诱导聚合蒙脱土插层纳米复合材料的研究

用两种光聚合法研究了蒙脱土插层复合材料的制备 .用小角X光衍射技术对产物内蒙脱土的结构进行表征 ,结果表明 ,蒙脱土经改性后能很好地使聚合单体及预聚物插入黏土层内并在光照下“就地”聚合生成光聚合复合材料 .对光聚合法制备蒙脱土纳米复合材料的优缺点进行了初步讨论     

聚乳酸/蒙脱土纳米复合材料的结构和热性能

聚乳酸/蒙脱土纳米复合材料的结构和热性能;聚乳酸;蒙脱土;纳米复合材料;插层     

悬浮缩聚法制备酚醛树脂/蒙脱土纳米复合材料

采用悬浮缩聚方法在酸性催化剂作用下制备了酚醛树脂/蒙脱土纳米复合材料。以三种不同的蒙脱土：天然土、带有脂肪链季铵盐修饰蒙脱土和带有苯环基团的插层剂修饰的蒙脱土为原料制备了纳米复合材料,并考察了不同插层剂对纳米复合材料形貌的影响,发现带有苯环的插层剂修饰的蒙脱土与酚醛树脂的相容性能更好;研究了固化过程对纳米复合材料形貌的影响,XRD和TEM的结构表明固化过程可以促进带有脂肪链季铵盐修饰的蒙脱土进一步剥离,对其他两类的影响不大;此外还用TGA研究了纳米复合材料的热性能。     

Effect of silver nanoparticles on the dynamic crystallization behavior of nylon‐6

The effect of introducing silver nanoparticles on the rheological properties and dynamic crystallization behavior of nylon‐6 was investigated. The nanocomposites showed slightly higher viscosity than pure nylon‐6 in the low‐frequency range even at an extremely low loading level of the silver particles (0.5–1.0 wt %). The nanoparticles had a more noticeable effect on the storage modulus than on the loss modulus of a nylon‐6 melt and reduced its loss tangent. They increased the crystallization temperature of nylon‐6 by about 14 °C and produced a sharper crystalline peak. The silver nanoparticles promoted the crystallization of nylon‐6, and their effect on the dynamic crystallization of nylon‐6 at 200 °C was more notable at a lower shear rate and at 190 °C at a higher frequency. Nylon‐6 produced large spherulitic crystals, but the nanocomposites showed a grainy structure. In addition, the silver nanoparticles reduced the fraction of the α‐form crystal but increased that of the γ‐form crystal. The nanocomposites crystallized at 190 °C showed a lower melting temperature than nylon‐6 by about 3 °C, whereas the nanocomposites crystallized at 200 °C showed almost the same melting temperature. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 790–799, 2004     

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     

Nonisothermal crystallization behavior of syndiotactic polystyrene/montmorillonite nanocomposites

X‐ray diffraction methods and differential scanning calorimetry were used to investigate the crystalline structure and crystallization kinetics of syndiotactic polystyrene (sPS)/clay nanocomposites. X‐ray diffraction data showed the presence of polymorphism in sPS/montmorillonite (MMT) nanocomposites, which was strongly dependent on the processing conditions (premelting temperature and cooling rate) of the sPS/MMT nanocomposites and on the content of MMT in the sPS/MMT nanocomposites. The α‐crystalline form could be transformed into β‐crystalline forms at higher premelting temperatures. The nonisothermal melt‐crystallization kinetics and melting behavior of the sPS/MMT nanocomposites were also studied at various cooling rates. The correlation of the crystallization kinetics, melting behavior, and crystalline structure of the sPS/MMT nanocomposites was examined. The results indicated that the addition of a small amount of MMT to sPS caused a change in the mechanism of nucleation and the crystal growth of the sPS crystallite. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 560–570, 2003     

Thermal,physical and mechanical properties of hydrogenated dimer acid-based Nylon 636/Nylon 66 copolymers

Hydrogenated dimer acid-based Nylon 636/NyIon 66 copolymers were synthesized by in situ polymerization.The effects of Nylon 66 contents on the copolymers were characterized by intrinsic viscosity measurements,attenuated total reflection-Fourier transform infrared spectroscopy,X-ray diffraction,differential scanning calorimetry,tliermogravimetric analysis and mechanical tests.The results showed that incorporation of Nylon 66 into hydrogenated dimer acid-based Nylon had no significant effect on the glass transition or melting temperatures.However,the crystallization temperature,crystallinity degree and the maximum rate of decomposition temperature from derivative thermogravimetry measurements vary.Mechanical testing data revealed that with increasing Nylon 66 concentrations,the tensile strength of copolymers increased,while the elongation at break point and notched izod impact strength decreased.The physical and mechanical properties of HN-40,HN-50 and HN-60 are similar to those of the current PA11,PA1212,and PA1111 Nylon products.     

Preparation and nonisothermal crystallization behavior of polyamide 6/montmorillonite nanocomposites

Polyamide 6 (PA6)/montmorillonite (MMT) nanocomposites were prepared via melt intercalation. The structure, mechanical properties, and nonisothermal crystallization kinetics of PA6/MMT nanocomposites were investigated by X‐ray diffraction (XRD), tensile and impact tests, and differential scanning calorimetry (DSC). Before melt compounding, MMT was treated with an organic surfactant agent. XRD traces showed that PA6 crystallizes exclusively in γ‐crystalline structure within the nanocomposites. Tensile measurements showed that the MMT additions are beneficial in improving the strength and the stiffness of PA6, at the expense of tensile ductility. Impact tests revealed that the impact strength of PA6/MMT nanocomposites tended to decrease with increasing MMT content. The nonisothermal crystallization DSC data were analyzed by Avrami, Ozawa, modified Avrami‐Ozawa, and Nedkov methods. The validity of these empirical equations on the nonisothermal crystallization process of PA6/MMT nanocomposites is discussed. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2878–2891, 2004     

Influence of SEBS-g-MA on morphology, mechanical, and thermal properties of PA6/PP/organoclay nanocomposites

Polyamide 6/polypropylene (PA6/PP = 70/30 parts) blends containing 4 phr (parts per hundred resin) of organically modified clay (organoclay) toughened with maleated styrene-ethylene-butylene-styrene (SEBS-g-MA) were prepared by melt compounding using co-rotating twin-screw extruder followed by injection molding. X-ray diffraction (XRD) and transmission electron microscope (TEM) were used to characterize the structure of the nanocomposites. The mechanical properties of the nanocomposites were determined by tensile, flexural, and notched Izod impact tests. The single edge notch three point bending test was used to evaluate the fracture toughness of SEBS-g-MA toughened PA6/PP nanocomposites. Thermal properties were studied by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). XRD and TEM results indicated the formation of the exfoliated structure for the PA6/PP/organoclay nanocomposites with and without SEBS-g-MA. With the exception of stiffness and strength, the addition of SEBS-g-MA into the PA6/PP/organoclay nanocomposites increased ductility, impact strength and fracture toughness. The elongation at break and fracture toughness of PA6/PP blends and nanocomposites were increased with increasing the testing speed, whereas tensile strength was decreased. The increase in ductility and fracture toughness at high testing speed could be attributed to the thermal blunting mechanism in front of crack tip. DSC results revealed that the presence of SEBS-g-MA had negligible effect on the melting and crystallization behavior of the PA6/PP/organoclay nanocomposites. TGA results showed that the incorporation of SEBS-g-MA increased the thermal stability of the nanocomposite.     

COMPARISON OF POLYAMIDE 66/MONTMORILLONITE NANOCOMPOSITES PREPARED FROM POLYAMIDE 6 AND POLYAMIDE 66 BASED MASTER-BATCHES

Two master-batches,polyamide 66 (PA66)/organo-montmorillonite (OMMT) and polyamide 6 (PA6)/OMMT, prepared by melt compounding with methyl methacrylate (MMA) as co-intercalation agent,have been used to prepare nearly exfoliated PA661montmorillonite (MMT) nanocomposites.The resulting nanocomposites are compared in view of their morphology and properties.Nano-scale dispersion of OMMT is realized in both types of nanocomposites,as revealed by XRD,TEM and Molau tests.PA66/MMT nanocomposites having superior me...     

Enhanced performance of biodegradable poly(butylene succinate)/graphene oxide nanocomposites via in situ polymerization

Poly(butylene succinate) (PBS)/graphene oxide (GO) nanocomposites were facilely prepared via in situ polymerization. The properties of the nanocomposites were studied using FTIR, XRD, and (1)H NMR, and the state of dispersion of GO in the PBS matrix was examined by SEM. The crystallization and melting behavior of the PBS matrix in the presence of dispersed GO nanosheets have been studied by DSC and polarized optical microscopy. Through the mechnical testing machine and DMA, PBS/GO nanocomposites with 3% GO have shown a 43% increase in tensile strength and a 45% improvement in storage modulus. This high performance of the nanocomposites is mainly attributed to the high strength of graphene oxide combined with the strong interfacial interactions in the uniformly dispersed PBS/GO nanocomposites.     

Polymorphic behavior in syndiotactic polystyrene/clay nanocomposites

X‐ray diffraction methods were used in an investigation of the structural changes in syndiotactic polystyrene (sPS)/clay nanocomposites. sPS/clay was prepared by the intercalation of sPS polymer into layered montmorillonite. Both X‐ray diffraction data and transmission electron microscopy micrographs of sPS/clay nanocomposites indicated that most of the swellable silicate layers were exfoliated and randomly dispersed in the sPS matrix. The X‐ray diffraction data also showed the presence of polymorphism in the sPS/clay nanocomposites. This polymorphic behavior was strongly dependent on the thermal history of the sPS/clay nanocomposites from the melt and on the content of clay in the sPS/clay nanocomposites. Quenching from the melt induced crystallization into the α‐crystalline form, and the addition of montmorillonite probably increased heterophase nucleation of the α‐crystalline form. The effect of the melt crystallization of sPS and sPS/clay nanocomposites at different temperatures on the crystalline phases was also examined. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 736–746, 2002