环氧树脂/有机累托石纳米复合材料的研究

用十二烷基二甲基苄基氯化铵对累托石进行有机化处理，采用不同量的有机累托石与环氧树脂进行原位插层聚合，制得环氧树脂／有机累托石纳米复合材料，采用红外光谱分析、X射线衍射分析、扫描电镜分析、差示扫描量热分析和力学性能测试研究了有机累托石在环氧树脂中的分散性、纳米复合材料的力学性能和热性能。结果表明，有机累托石含量为3份时纳米复合材料的综合性能最佳，冲击强度和弯曲强度分别提高40％和33％；热变形温度和玻璃化转变温度分别提高30℃和11．5℃；而其热稳定性与纳米累托石粒子的分布和界面作用有关。     

聚碳酸亚丙酯/纤维素复合材料的制备和性能

采用双螺杆挤出机制备了完全可生物降解的聚碳酸亚丙酯/纤维素复合材料,并对复合材料的性能进行表征和研究。研究结果表明:聚碳酸亚丙酯和纤维素之间的相容性较差,纤维素含量较少时,可以均匀分散在聚碳酸亚丙酯基体中;当纤维素含量增加时,纤维素会大量团聚。聚碳酸亚丙酯/纤维素复合材料的热稳定性、玻璃化转变温度和力学性能等随着纤维素含量的增加也随之提高。纤维素质量分数为30%时,复合材料的T5%、T50%和Tmax分别达到256.6、313.1和308.0℃,比纯PPC提高了约50℃;复合材料的玻璃化转变温度为48℃,与纯PPC相比提高了16℃。另外,复合材料的拉伸强度为45 MPa,大约是聚碳酸亚丙酯的5.6倍,同时复合材料的维卡软化点为43℃,比聚碳酸亚丙酯提高了11℃。     

纳米纤维素对聚碳酸亚丙酯力学性能的影响研究

将自制的纳米纤维素与聚碳酸亚丙酯通过熔融共混制备成纳米复合材料,考察纳米纤维素的添加量对复合材料力学性能的影响。全反射傅里叶红外光谱分析结果表明,聚碳酸亚丙酯与纳米纤维素仍具有各自的化学结构,二者并没有发生化学变化。扫描电镜结果显示,随着纳米纤维素含量的增加,复合材料的相形态由"海-岛"结构变为纤维状聚集结构;当纳米纤维素的含量在1.5%时,复合材料的拉伸强度可达38.33 MPa,较聚碳酸亚丙酯提升了288%,断裂伸长率为原来的1.6%,复合材料由韧性断裂转为脆性断裂。实验表明,纳米纤维素的加入能显著增强聚碳酸亚丙酯的力学性能。     

苎麻纤维增强聚碳酸亚丙酯复合材料的工艺与性能研究

采用苎麻纤维和聚碳酸亚丙酯制备了可降解复合材料,讨论了苎麻长度、含量对苎麻/聚碳酸亚丙酯复合材料机械性能的影响,并借助扫描电子显微镜对复合材料的冲击断口形貌进行了观察.结果表明:苎麻经碱液处理后,苎麻/聚碳酸亚丙酯复合材料的拉伸性能和冲击性能有了明显提高.     

累托石/NR纳米复合材料的结构与性能研究

研究乳液法和熔体法制备的累托石／NR纳米复合材料的结构与性能。结果表明,乳液法累托石／NR纳米复合材料为层间无高分子插入的隔离型纳米复合材料,熔体法累托石／NR纳米复合材料为典型的插层型纳米复合材料;当应变小于100％时,熔体法制备的复合材料应力较大,当应变大于100％时,乳液法制备的复合材料应力较大;当累托石用量较小时,乳液法制备的复合材料撕裂强度高于熔体法制备的复合材料;乳液法和熔体法制备的两种复合材料热稳定性差别不大,均好于纯NR。     

累托石在聚合物纳米复合材料中的应用

介绍了一种用于聚合物纳米复合材料的新型层状硅酸盐材料——累托石粘土,从矿物的结构特点分析了它用于聚合物纳米复合材料的改性、插层、剥离的可行性及性能特点,还介绍了用累托石改性的尼龙6、聚丙烯、聚氨酯弹性体等纳米复合材料,其综合性能优于同类聚合物／蒙脱石纳米复合材料,     

MAH改性PPC对PLA形状记忆与力学性能的影响

采用马来酸酐(MAH)作为封端剂与聚碳酸亚丙酯(PPC)进行接枝反应,制备了MAH改性聚碳酸亚丙醋(M-PPC).将M-PPC用于聚碳酸亚丙酯/聚乳酸(PPC/PLA)复合材料中,考察了MAH对PPC/PLA复合材料的力学性能、形状记忆性能和热稳定性的影响.扫描电镜(SEM)观察到M-PPC对复合材料界面影响显著,力学...     

聚丙烯酸-腐植酸-累托石复合吸附剂的制备方法

正申请(专利权)人:江苏科技大学申请日期:2012.04.26申请(专利)号:CN201210125575主分类号:B01J20/30;C02F1/28;B01J20/28本发明公开了一种聚丙烯酸-腐植酸-累托石复合吸附剂的制备方法,它是采用有机季铵盐与累托石发生阳离子交换反应形成有机累托石,然后使丙烯酸原位聚合于有机累托石的纳米层间,形成插层型聚合物/粘土复合材料,同时负载上腐殖酸,制得聚丙烯酸-腐殖酸-累托石复合吸     

在超临界CO2中制备生物可降解PEC/OMMT纳米复合材料

将聚碳酸亚乙酯(PEC)与有机蒙脱土(OMMT)在超临界CO2(sc-CO2)中溶胀并混合,制备了生物可降解PEC/OMMT纳米复合材料。采用X射线衍射仪、热失重分析仪、差示扫描量热仪及万能电子拉力机等对PEC/OM-MT纳米复合材料的性能进行表征和分析。结果表明,70℃下制备的PEC/OMMT复合材料为插层型纳米复合材料;该复合材料的热稳定性和玻璃化转变温度都得到较大改善;加入少量OMMT,复合材料的拉伸性能得到明显提高。与熔融插层法和溶液插层法相比,sc-CO2法既可以解决PEC在熔融插层中面临的热降解问题,也可以避免溶液插层中使用大量有机溶剂造成的污染问题,是制备PEC/OMMT纳米复合材料的一种新方法。     

累托石纳米复合材料的结构和性能

以具有层状硅酸盐结构的累托石(REC)为主体、烷基季铵盐为改性剂合成了有机累托石(OREC)，以有机累托石和环氧树脂复合制备纳米复合材料。累托石含量在0.8％(w)时，纳米复合材料具有最佳力学和热学性能，其中冲击强度增加120％，断裂伸长率增加330％，玻璃化转变温度提高28℃。用X-小角衍射法、透射电镜和红外吸收光谱研究了材料的微观结构，结果表明层状累托石和环氧树脂发生了化学反应，并观测到层状累托石完全剥离和插层两种结构形态。累托石在低含量时容易形成剥离型。     

Synthesis and characterization of UV-curing epoxy acrylate coatings modified with organically modified rectorite

Epoxy acrylate (EA) coatings modified with organically modified rectorite (OREC) were synthesized employing the ultraviolet-curing technique. Two kinds of alkyl ammonium ions, octadecyltrimethylammonium chloride (OTAC) and [2-(methacryloyloxy)ethyl]trimethylammonium chloride (MAOTMA), were used to modify rectorite (REC). The methacrylate functionalities of MAOTMA were capable of reacting with the acrylate groups of EA. The structure of OREC was characterized by FTIR and XRD and the results indicated that the surfactants were successfully intercalated into the REC interlayers via cation exchange process. The morphology of nanocomposites was investigated by SEM and TEM. OREC showed better dispersion in EA matrix compared with unmodified REC. The T _g of neat EA obtained by DMA was 75.6°C, while for 5 wt% EA/MAOTMA-REC and EA/OTAC-REC nanocomposites it increased to 76.5 and 80.8°C, respectively. The nanocomposite with 3 wt% loading of OTAC-REC had the highest T _g (89.7°C). TGA revealed that the thermal stability of nanocomposites was enhanced by OTAC-REC and MAOTMA-REC and the thermal stability of EA/MAOTMA-REC nanocomposites was better than that of EA/OTAC-REC nanocomposites. The mechanical properties of nanocomposites containing OTAC-REC and MAOTMA-REC were better than those of nanocomposites containing unmodified REC. With increasing OREC content, the adhesive force of nanocomposites decreased slightly and the flexibility increased significantly.     

Rectorite/thermoplastic polyurethane nanocomposites. II. Improvement of thermal and oil‐resistant properties

Organ‐rectorite/thermoplastic polyurethane (OREC/TPUR) nanocomposites were synthesized via melt intercalation. The dynamic mechanical properties by dynamic mechanical analysis (DMA), thermal and oil‐resistant properties were investigated. The results show that the storage modulus (E′), loss modulus (E″), and glass‐transition temperature (T_g) of the nanocomposites have an increase to some extent than those of pure TPUR. The thermal stability of nanocomposites was also studied in detail by thermal gravity analysis (TGA), which was higher than that of pristine TPUR matrix when the content of organic REC is at 2 wt %, and the decomposition temperature at 10% weight loss of OREC/TPUR is greatly increased up to 330°C from 315°C. Oil uptake of the composites is also significantly reduced in comparison with TPUR matrix, which is ascribed to the good barrier effect of nanosheets of OREC. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1165–1169, 2005     

Rectorite/thermoplastic polyurethane nanocomposites: Preparation,characterization, and properties

A newly developed kind of layered clay, rectorite (REC), has been used to yield intercalated or exfoliated thermoplastic polyurethane rubber (TPUR) nanocomposites by melt‐processing intercalation. Because of the swollen layered structure of REC, similar to that of montmorillonite, organic rectorites (OREC) can also be obtained through ion‐exchange reaction with two different quaternary ammonium salts (QAS1, QAS2) and benzidine (QAS3). The microstructure and dispersibility of OREC layers in TPUR matrix were examined by X‐ray diffraction and transmission electron microscopy, which revealed not only that the composites with lower amounts of clay are intercalation or part exfoliation nanocomposites, but also that the mechanical properties of the composites were substantially enhanced. The maximum ultimate tensile strength for TPUR/OREC nanocomposites appeared at 2 wt % OREC loading. With increasing OREC contents, the tear strength of the composites increased significantly. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 608–614, 2004     

The excellent gas barrier properties and unique mechanical properties of poly(propylene carbonate)/organo-montmorillonite nanocomposites

Intercalated nanocomposites comprised of poly(propylene carbonate) (PPC) and organo-montmorillonite (OMMT) were prepared via a direct melt blending method. The morphological, thermal, rheological, mechanical, and gas barrier properties of composites were carried out in detail. Results of XRD, TEM, and SEM revealed that OMMT dispersed homogeneously in the polymer matrix, and were intercalated by PPC macromolecules. Compared with neat PPC, the PPC/OMMT nanocomposites showed an enhancement in the 5 wt% weight loss temperature (T _?5%) by near 20 °C with 3 phr OMMT concentration. With the percolation threshold formed, the rheological properties of composites translated from a liquid-like behavior to a solid-like one. Interestingly, PPC/OMMT nanocomposites revealed a concurrent improvement in the modulus, yield strength, and toughness with the addition of homogeneously dispersed clay. The oxygen permeability of well-dispersed PPC/OMMT nanocomposites reduced significantly compared with that of neat PPC. Consequently, this convenient and effective method, which facilitates to prepare PPC/OMMT nanocomposites with superior mechanical properties and excellent gas barrier performances, can be considered to broaden the application of PPC.     

Morphology and thermal/mechanical properties of alkyl‐imidazolium‐treated rectorite/epoxy nanocomposites

A novel organic rectorite (OREC) was prepared by treating the natural sodium‐rectorite (Na‐REC) with ionic liquid 1‐hexadecyl‐3‐methylimidazolium bromide ([C₁₆mim]Br). X‐ray diffraction (XRD) analysis showed that the interlayer spacing of the OREC was expanded from 2.23nm to 3.14nm. Furthermore, two types of OREC/epoxy nanocomposites were prepared by using epoxy resin (EP) as matrix, 2‐ethyl‐4‐methylimidazole (2‐E‐4‐MI) and tung oil anhydride (TOA) as curing agents, respectively. XRD and transmission electron microscope (TEM) analysis showed that the intercalated nanocomposite was obtained with addition of the curing agent 2‐E‐4‐MI, and the exfoliated nanocomposite was obtained with addition of the curing agent TOA when the OREC content was less than 2 wt %. For the exfoliated nanocomposite, the mechanical and thermal property tests indicated that it had the highest improvement when OREC content was 2 wt% in EP. Compared to pure EP, 60.3% improvement in tensile strength, 26.7% improvement in bending strength, 34% improvement in bending modulus, 14°C improvement in thermal decomposition temperature (T_d) and 5.7°C improvement in glass transition temperature (T_g) were achieved. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

PLA/PPC/OMMT纳米复合材料的结构与性能研究

采用双螺杆挤出机制备了聚乳酸（PLA）/聚碳酸亚丙酯（PPC）共混物和PLA/PPC/有机改性蒙脱土（OMMT）纳米复合材料,采用偏光显微镜、差示扫描量热仪和力学性能试验机等对共混物和纳米复合材料的相态结构、熔融与结晶行为和力学性能等进行了研究。结果表明,在PPC含量低于30 %时,随着PPC含量的增加,PLA/PPC和PLA/PPC/OMMT体系中PLA的玻璃化转变温度（Tg）均降低,在PPC含量为50 %时出现了明显的相分离;随着PPC含量的增加,PLA/PPC的冲击强度增大;OMMT的含量小于1.5 %时,PLA/PPC/OMMT体系的结晶度、拉伸强度、断裂伸长率和冲击强度均随OMMT含量的增加而增大。     

Synthesis and characterization of poly(propylene carbonate)/modified sepiolite nanocomposites

A series of poly(propylene carbonate) (PPC)/modified sepiolite (mSp) nanocomposites with different mSp contents were prepared via a solution‐based processing method. The modified sepiolite was obtained by fabricating sepiolite with methyl trimethoxysilanes (MTMS) gel. The effect of mSp amount, in the range 1–10 wt%, on the morphology, mechanical properties, and thermal degradation of PPC was investigated by means of scanning electron microscopy (SEM), X‐ray diffractometry (XRD), static strenching analysis, thermogravimetric analyses (TGA), differential scanning calorimetry (DSC). Morphological studies showed the homogeneous dispersion of mSp in the PPC matrix whose structure remains amorphous. The nanoscale dispersion of mSp significantly enhanced the mechanical properties and thermal stability. The thermal motion and degradation of the polymer occur at higher temperature in the presence of mSp because of the strong interfacial adhesion between the two components. POLYM. COMPOS., 21–27, 2016. © 2014 Society of Plastics Engineers     

Nanocomposites of poly(propylene carbonate) reinforced with cellulose nanocrystals via sol‐gel process

Cellulose nanocrystals (CNCs) organogels were first produced from aqueous dispersion through solvent exchange of CNCs to acetone via a simple sol‐gel process. After mixing the organogels with poly(propylene carbonate) (PPC) in dimethylformamide followed by solution casting, green nanocomposites were obtained with CNCs well dispersed in PPC polymer matrix which was confirmed by scanning electron microscopy observations. Differential scanning calorimeter analysis revealed that glass transition temperature of the nanocomposites was slightly increased from 34.0 to 37.4°C. Tensile tests indicated that both yield strength and Young's modulus of CNCs/PPC nanocomposites were doubled by adding 10 wt % CNCs. However, poor thermal stability of PPC occurred after incorporating with CNCs due to the thermo‐sensitive sulfate groups located on the surface of CNCs. Furthermore, PPC became more hydrophilic because of the inclusion of CNCs according to the water contact angle measurement. The enhanced mechanical and hydrophilic properties, coupled with the inherent superior biocompatibility and degradability, offered CNCs/PPC composites potential application in biomedical fields. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40832.     

原位聚合有机累托石/聚甲基丙烯酸甲酯凝胶聚合物电解质的性能

以有机增塑剂聚碳酸丙烯酯(propylene carbonate,PC)为聚合反应溶剂,通过自由基引发原位聚合法制备了有机累托石/聚甲基丙烯酸甲酯(organic-modified rectorite/polymethyl methacrylate,OREC/PMMA)纳米复合凝胶聚合物电解质(nanocomposite gel polymer electrolyte,NGPE).用交流阻抗法分析了凝胶电解质的电性能,并研究了温度对电性能的影响.通过红外光谱分析其组分间的相互作用.用差示扫描量热分析和热失重分析分析凝胶电解质的热稳定性.结果表明:OREC/PMMA组成的NGPE的本体阻抗值随OREC添加量的增加呈现出先减小后增大的趋势,当OREC的添加质量为5%时,NGPE在不同温度下均具有最大的离子电导率(σ).OREC与PC,PMMA及锂盐之间存在一定的相互作用,从结构的角度解释了OREC添加提高体系σ的机理.添加OREC能在一定程度上改善体系的凝胶热稳定性.     

累托石的有机改性及其对凝胶聚合物电解质的影响

用十二烷基二甲基苄基氯化铵改性天然黏土累托石,得到有机改性累托石(organic modified rectorite,OREC),再用OREC改性凝胶聚合物电解质.对OREC进行红外、X射线衍射、偏光显微分析,并对OREC改性的凝胶聚合物电解质体系的X射线衍射结果、离子电导率及热性能进行了分析.结果表明:OREC能作为改性剂用在凝胶聚合物电解质中,在凝胶电解质中达到完全解离,能提高电解质的离子电导率,且改性电解质的玻璃化转变温度随OREC添加量的增加而增大,热稳定性提高.