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...     

PREPARATION AND CHARACTERIZATION OF POLYAMIDE 11/CLAY NANOCOMPOSITES

INTRODUCTIONIn recent years, polymer/clay nanocomposites have attracted great interest from researchers since they frequentlyexhibit unexpected hybrid properties synergistically derived from the two components. Compared to their microcounterparts and the pristine polymer matrix, polymer/clay nanocomposites exhibit improved tensile strength andmodulus, decreased thermal expansion coefficient, decreased gas permeability, increased swelling resistance,enhanced ion conductivity, and reduced fl…     

聚氨酯/蒙脱土纳米复合材料的制备与性能研究

纳米复合材料由于其纳米尺寸效应 ,表面效应以及纳米粒子与基体界面间强的相互作用 ,具有优于相同组分常规复合材料的力学 ,热学等性能 ,引起了人们的广泛关注 .用纳米材料改性聚合物 ,制备纳米复合材料是获得高性能高分子复合材料的重要方法 ,采用较多的是插层复合法 ,可分为两类 ,一是单体预先插层于层状结构填料的晶片层间 ,然后聚合 ;二是聚合物溶液或熔体直接插层于层状结构填料的晶片层间 .聚氨酯 (PU)是由多异氰酸酯与多元醇通过加聚反应而形成的高聚物 ,其重复结构单元是氨基甲酸酯链段( R2 OCONHR1NHCOO) .PU弹性体具有耐磨…     

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     

羧甲基纤维素钠/蒙脱土纳米复合膜的制备及性能

用溶液插层法制备出了剥离型羧甲基纤维素钠 蒙脱土纳米复合物 .X射线衍射结果中蒙脱土d0 0 1 峰的消失证实了纳米复合物的生成 ,透射电镜观察表明硅酸盐片层在羧甲基纤维素钠基体中达到了纳米级的分散 .红外测试表明 ,羧甲基纤维素钠分子上的醚键和蒙脱土分子上的硅氧键、铝氧键之间强的作用力是插层的驱动力 .加入蒙脱土后 ,提高了羧甲基纤维素钠膜的拉伸强度、热稳定性 ,降低了其水蒸汽透过系数 .     

硅橡胶/蒙脱土复合材料的制备、结构与性能

用溶液法和熔融法制备了硅橡胶／蒙脱土复合材料，测定了力学性能、耐热性、耐溶剂性等性能．并与通常采用的２＃气相法白碳黑填充补强硅橡胶的性能作了对比．实验表明，溶液法能使蒙脱土更好地分散在硅橡胶基体中，所得到的复合物的性能有了很大的提高，与２＃气相法白碳黑填充补强的硅橡胶性能相当．     

Preparation and characterization of nylon 66/montmorillonite nanocomposites with co-treated montmorillonites

In this paper, a new type of organophilic montmorillonites, co-treated by octadecylammonium and aminoundecanoic acid, were synthesized and applied to prepare nylon 66/montmorillonite nanocomposites via melt compounding in a twin extruder. WAXD and TEM characterization indicate that a disordered structure was derived and the montmorillonite platelets dispersed in nanoscale in the nylon 66 matrix. The nanocomposites with co-treated montmorillonite display comparatively higher strength and modulus compared to nylon 66 matrix.     

聚氨酯弹性体/蒙脱土纳米复合材料的合成与性能

采用聚氨酯本体预聚法 ,利用原位插层聚合合成了聚氨酯 蒙脱土纳米复合材料 .通过X 射线衍射(XRD)和Molau实验研究了蒙脱土在复合材料中的分散情况 .红外分析 (IR)表明随着蒙脱土含量的增加 ,复合材料羰基氢键减少 .动态力学分析 (DMA)以及差热分析 (DSC)结果说明随着蒙脱土含量的增加 ,材料的玻璃化温度降低 .聚氨酯纳米复合材料的拉伸强度和断裂伸长率同时提高 ,表现出较好的力学性能 .     

熔体插层制备尼龙6/蒙脱土纳米复合材料的性能表征

通过熔体插层成功地制备了尼龙６／蒙脱土纳米复合材料，测试了力学性能、耐热性能和耐溶剂性．通过ＴＥＭ、ＷＡＸＤ、ＤＳＣ等手段，研究了结构与结晶行为，并与插层聚合的尼龙６／蒙脱土纳米复合材料进行了对比．实验表明通过熔体插层可使尼龙６基体插层于蒙脱土中，所得到的复合物的性能较尼龙６有很大提高，且与插层聚合的尼龙６／蒙脱土纳米复合材料的性能相当．     

原位插层聚合制备聚丁二烯/蒙脱土纳米复合材料的结构与性能研究

聚合物 /粘土纳米复合材料由于具有常规复合材料所没有的结构、形态及更优异的力学、热学、阻燃、阻隔等性能 ,自 1 987由日本丰田公司首次报道了制备尼龙 6 粘土纳米复合材料以来 ,立刻引起人们的普遍关注[1～ 17] .目前报道的聚合物 /粘土纳米复合材料主要集中在以树脂为基体 ,例如 ,聚酰胺[1～ 4] 、聚苯乙烯[5～ 8] 、聚甲基丙烯酸甲酯[9,10 ] 、聚丙烯[11,12 ] 等 .制备以橡胶为基体的橡胶/粘土纳米复合材料研究较少 ,采用的方法多为通过橡胶大分子插层 ,如熔融插层法[1 3] 、溶液插层法[14 ] 、乳液法[15,16] 等 ,这些方法均存在插层…     

聚萘并噁嗪/蒙脱土纳米复合材料的制备与表征

用原位插层反应法地制备了聚萘并嗪 蒙脱土纳米复合材料 .采用X ray衍射 (XRD)及透射电镜(TEM)研究复合材料中蒙脱土硅酸盐片层间距 ,发现硅酸盐片层间距由 1 2 6nm扩增至 5 88nm以上 .同时研究了该复合材料的耐热性 ,并探讨了复合材料的结晶行为     

SYNTHESIS AND CHARACTERIZATION OF COMB-SHAPED POLYBUTADIENES

Polybutadiene (PB) was chlorinated with t-BuOCl without chain crosslinking and degradation togive chlorinated polybutadiene (Cl--PB) with active allylic chlorine atoms on the backbone. Comb-shaped PB was prepared by coupling of Cl--PB with "living" PB anions in a mixed solvent of cyc-lohexane and tetrahydrofuran. Characterization by GPC and osmometry showed that purifiedproducts were welldefined comb-shaped PB composed of low polydispersity backbone chain andrandomly distributed grafts of uniform length. The averagr number of branches could be variedin a wide range to meet the needs of structure-properties relationship studies.     

双单体原位接枝插层法制备聚丙烯纳米复合材料的研究Ⅰ.制备、表征及力学性能的研究

用有机插层剂处理蒙脱土原土 ,制得有机蒙脱土 (O MMT) .采用双单体 (马来酸酐和苯乙烯 )原位接枝插层法 ,制备了聚丙烯 蒙脱土纳米复合材料母料 .将母料与聚丙烯基体在双螺杆上共混挤出 ,制得聚丙烯 蒙脱土纳米复合材料 (PP Montmorillonetenanocomposites,PMNC) .这是制备聚合物纳米复合材料的一种新方法 .通过X 射线衍射测试 (XRD)表明 ,有机蒙脱土片层 0 0 1面间距从原土的 1 4 9nm扩大到 2 96nm ,复合材料中蒙脱土片层 0 0 1面间距由有机蒙脱土的 2 96nm扩大到 4 0nm .力学性能测试表明 ,复合材料的力学性能明显优于PP基体 ,在提高材料拉伸强度的同时 ,缺口冲击强度也得到很大的提高 .用扫描电镜 (SEM)对材料的冲击断面形貌进行了研究 ,并从理论上分析了断裂机理 .随着蒙脱土含量的增加 ,冲击断裂形式逐渐从脆性断裂变成韧性断裂     

原位插层聚合制备聚丁二烯/蒙脱土纳米复合材料及其结构与性能研究

采用负离子引发原位插层聚合法制备了聚丁二烯(PB)/有机蒙脱土(OMMT)纳米复合材料(NC).对OMMT纯化方法、OMMT种类和溶剂等因素对聚合反应的影响进行了研究.不同方法纯化的OMMT消耗的BuLi量相差一倍;采用OMMT-DK1制备的NC具有较宽的分子量分布,而采用OMMT-DK1B和OMMT-DK4制备的NC则具有较窄的分子量分布;OMMT在环己烷中不溶解,在甲苯和二甲苯等溶剂中可形成均匀溶液.采用XRD、TEM和H-NMR等仪器对PB/OMMT NC的插层结构、化学结构和形态进行了分析;采用DSC、TGA和DMA等仪器对PB/OMMT NC的Tg、热学性能和动态力学性能进行了研究,结果表明,采用负离子原位插层聚合可得到剥离型PB/OMMT纳米复合材料;与OMMT插层复合明显改变了PB的微观结构组成,在OMMT含量为6.2wt%时,1,2-结构含量增加了近一倍,Tg和Tdc分别增加了10 K和16 K;E′、E″均明显提高,而tanδ下降.     

SYNTHESIS AND CHARACTERIZATION OF TITANOCENE POLYMER DERIVATIVES

Titanocene polymer derivatives with potential antitumor properties were synthesized by interfacial condensation. The preformed polymers used are PAA (polyacrylic acid), CPSMA (1:1 alternating copolymer of styrene and maleic anhydride) and DVEMA (1:2 copolymer of divinyl ether and maleic anhydride). The ratio of practical and theoretical titanium content is 73.6%, 92.2% and 86.2% for PAA, CPSMA and DVEMA polymer derivatives respectively. The IR spectra of the polymer derivatives possess the characteristic absorptions of titanocene. XPS (X-ray photoelectron spectroscopy) of O_(1s) and Ti_(2p3/2) supports the existence of Ti-O bonding.     

DISPERSION AND TENSILE BEHAVIOR OF POLYPROPYLENE/MONTMORILLONITE NANOCOMPOSITES PRODUCED VIA MELT INTERCALATION

Most of the anicles on polymer nanocomposites focus on the importance of chemistry used to modify the surfaceof the clay, usually montmorillonite (MMT), and characterization of the nano-scale structure obtained. The role andimportance of processing were also discussed recently. However, few papers concerning the correlation between morphologyof MMT and mechanical properties were published. In order to understand the tensile behavior of PP/Montmorillonite(MMT) nanocomposites better, and to further improve the reinforcement efficiency, we first prepared the PP nanocompositesvia direct melt intercalation using conventional twin-screw extrusion. The dispersion and tensile property of the compositeswere then investigated by SEM, XRD, TEM and a video-controlled tensile set-up. The macroscopic and microscopicdispersion of MMT in PP matrix was verified by XRD and TEM, combined with SEM. The tensile properties were obtainedby video-controlled tensile set-up, which gives true stress-strain curve. It was found that a partly intercalated and partlyexfoliated structure (also called incomplete exfoliation) existed in the system. Though the tensile strength of PPnanocomposites is not much improved in engineering stress-strain curves, more than 20% increase of true stress was found ina true stress-strain experiment at high true strain, which indicates that only oriented silicate layers can have a big effect ontensile properties. Not only orientation of silicate platelets but also the degree of exfoliation is a key factor to determine thereinforcement efficiency. The reinforcement efficiency of MMT has been discussed based on the "continuum" Halpin-Tsaiequations. A good agreement was found between experimental data and theoretical prediction by changing N value (number of platelets per stack) which corresponding to different state of the dispersion of MMT in PP matrix.     

尼龙66/蒙脱土复合材料结晶行为的研究

在密炼机中采用熔融共混法制备蒙脱土重量分数为 2 5 %、4 5 %的尼龙 6 6 /蒙脱土复合材料 .通过DSC法对非等温结晶行为及在 2 2 8～ 2 4 0℃范围内的等温结晶行为进行研究 ,并与纯尼龙 6 6进行比较 .从其等温和非等温结晶行为的研究表明 ,蒙脱土起成核剂的作用 ,它的填入使尼龙 6 6结晶速率提高 ,但填料与基体间的相互作用使其链段运动困难 ,结晶活化能提高 ;在研究的填料含量变化范围内 ,结晶行为变化不大 ,并且找到该复合材料在 2 2 8～ 2 34℃范围结晶对温度的不敏感区 ;对非等温结晶过程分析 ,刘结平 莫志深方程是适用的 ,而Ozawa方程则是不适用的 .     

RHEOLOGICAL BEHAVIOR OF POLYPHENYLENE SULFIDE/POLYAMIDE-66 BLENDS

Blends of polyphenylene sulfide (PPS) containing trace amounts of branching and/orcross-linking in chain and Polyamide-66(PA-66) have been prepared by melt blending. Therheological behavior of PPS/PA-66 blends has been studied by means of capillary rheo-meter, and compared with PPS. The effects of shear rate, shear stress and temperature onthe flow of PPS/PA-66 blends and PPS are discussed. The non-Newtonian indexes andthe activation energies of viscous flow are obtained. The results show that the apparentviscosity of PPS/PA-66 blends is not sensitive to shear rate and stress, but decreases withthe elevation of temperature. On the contrary, the apparent viscosity of the PPS decreasesobviously with the increasing of shear rate and shear stress, but it is increased by theelevation of temperatue.     

STUDIES ON THE INTERFACIAL ADHESION BETWEEN FUNCTIONALIZED POLYPROPYLENE AND POLYAMIDE 1010*

The interface behavior of polyamide 1010 (PA1010) and polypropylene (PP) was studied. In orderto improve their interfacial adhesion, functional PP was prepared by means of grafting glycidyl methacrylate(GMA) on PP main chains and used instead of plain PP. Several technological characterizations wereperformed here on their interfaces. ESCA was used to confirm that some kind of reaction occurred betweenend groups of PA1010 and epoxy species of PP-g-GMA. The peel test was adopted to measure interfacialadhesion. It was found that the fracture energy of interfaces between PA1010 and PP-g-GMA wasdramatically increased with the content of GMA. Their interfaces were observed as being blurred by usingSEM and TEM and a crack that could be seen in the case of the interfaces of the PA1010 and the plain PPdisappeared.     

SYNTHESIS AND CHARACTERIZATION OF DVE-CO-MA DERIVATIVES OF CIS- PLATINUM COMPLEXES

Copolymer of divinyl ether and maleic anhydride (DVE-co-MA) derivatives of cis-platinum complexes were synthesized and characterized by elementary analysis, IR and XPS ( X-ray photoelectron spectroscopy). The behavior of the products in biological environment was also studied. UV-visible and fluorescence spectra show that these polymer derivatives are able to exchange ligands with selected nucleophilic groups in biological environment.