HPMA/OMMT和HPMA/CPMI/OMMT纳米复合材料的制备与表征

通过甲基丙烯酸羟丙酯(HPMA)单体与N-(4-羧基苯基)马来酰亚胺(CPMI)单体在有机蒙脱土(OMMT)中经原位插层自由基聚合反应制备了聚合物-无机纳米复合材料.OMMT由钠基蒙脱土通过十六烷基溴化铵插层处理制备.通过XRD和TEM对复合材料结构进行了表征,证实HPMA单体和HPMA/CPMI共单体在OMMT中原位插层共聚得到的复合材料均为剥离型纳米复合材料.OMMT含量为3 wt%的PolyHPMA/OMMT纳米复合材料起始分解温度为250℃,比相应的纯聚合物的热分解温度提高30℃.随着OMMT含量的增加,热分解温度进一步提高.但在测试温度范围内,PolyHPMA/OMMT纳米复合材料均没有出现明显的玻璃化转变温度.     

漆酚钛聚合物/蒙脱土纳米复合材料的制备、结构与性能

用溶液插层聚合方法制备漆酚钛聚合物/蒙脱土纳米复合材料(PUTi/OMMT),并用XRD、TEM和TG等对其结构、性能进行测试与表征.XRD结果表明,通过溶液插层,PUTi分子链进入了OMMT片层间,从而使片层间距增大.TEM观察表明OMMT片层在PUTi聚合物中基本达到纳米级分散.与PUTi相比,PUTi/OMMT纳米复合材料具有更好的耐热性能和抗紫外光性能.     

聚碳酸1,2-丙二酯/蒙脱土复合材料的制备与性能

利用阳离子交换法,以十六烷基三甲基溴化铵(HTAB)改性钠基蒙脱土制备了有机改性蒙脱土(OMMT),OMMT的层间距达到了2nm,比普通的钠基蒙脱土增加了0.74nm.采用熔融插层法制备了插层-絮凝型PPC/OMMT复合材料,当复合材料中OMMT含量为5wt%时,复合材料的杨氏模量较纯PPC树脂大幅度提高了61.8%,同时玻璃化温度(Tg)提高了2.4℃,热分解温度提高了32.3℃.因此,OMMT对大幅度提高PPC的杨氏模量具有很大的潜力.     

偏氯乙烯共聚物/层状双金属氢氧化物纳米复合材料的制备与表征

通过硝酸根插层层状双金属氢氧化物(LDH)与可逆加成-断裂链转移(RAFT)试剂S,S’-对(α,α’-二甲基-α″-乙酸)三硫代碳酸酯(CTA)阴离子的离子交换制备CTA阴离子插层LDH,再通过原位RAFT活性自由基聚合制备偏氯乙烯-丙烯酸甲酯(VDC-MA)共聚物/LDH纳米复合材料.采用傅里叶变换红外光谱、元素分析和X-射线衍射、透射电子显微镜、凝胶渗透色谱仪和热失重仪表征了CTA阴离子插层LDH和纳米复合材料的结构和性能.结果表明,CTA阴离子可以置换硝酸根阴离子插入到LDH层间,LDH层间距由0.89 nm增大到1.50 nm;在原位RAFT聚合过程中,LDH逐渐剥离,LDH以纳米层板形式分散在VDC-MA共聚物基体中;VDC-MA共聚物数均分子量随加入的插层CTA阴离子含量增加而减小,聚合具有活性特征.此外,含量LDH的引入可明显提高VDC-MA共聚物的热稳定性.     

界面作用对PMMA/MCM-41/OMMT复合材料性能的影响

通过单体插层原位本体聚合的方法, 制备了多种不同含量的聚甲基丙烯酸甲酯(PMMA)/蒙脱土/介孔分子筛(无模板剂)复合材料. 研究了不同结构填料与基体间的界面作用, 以及不同结构填料的比例变化对复合材料性能的影响. 研究结果表明: 有机蒙脱土(OMMT)与介孔分子筛MCM-41(无模板剂)共同作为填料, 与基体发生较强的界面效应, 形成新型网络复合结构, 两种粒子起到了协同增强作用|当有机蒙脱土(OMMT)/介孔分子筛(MCM-41)混合填料(比例为1∶1)含量为0.5%时, PMMA基纳米复合材料的拉伸强度达到最大值49.0 MPa, 比PMMA提高了15%|同时添加OMMT和MCM-41的PMMA基纳米复合材料的热稳定性高于单独添加OMMT或MCM-41的PMMA基复合材料.     

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.     

插层聚合制备聚丙烯/蒙脱土纳米复合材料及其结构性能表征

将插层聚合的概念引入烯烃聚合,制备了聚丙烯／蒙脱土（PP／MMT）纳米复合材料。X射线衍射和TEM分析结果表明,蒙脱土在聚丙烯基体中达到了纳米级的分散,动态力学性能研究结果表明,在高于Tg的温度区域内PP／MMT纳米复合材料的储能模量（E′）成倍增加,加入8％的蒙脱土（MMT）,PP／MMT的E′提高近3倍。PP／MMT的玻璃化转变温度Tg有一定程度的提高,随蒙脱土含量的增加,PP／MMT的热分解温度和热变形温度（HDT）都有大幅度提高。     

尼龙6/石墨纳米导电复合材料的制备与性能

通过原位插层聚合制备了尼龙 6 /石墨纳米导电复合材料 ,其室温导电渗滤阈值为 =0 75vol% ,远远低于常规导电粒子填充的聚合物复合材料 .当石墨体积分数为 2 0vol%时 ,室温电导率可达 10 -4 S/cm .透射电镜研究表明 :由于石墨经高温膨胀后其片层被剥离导致了片状石墨粒子具有巨大的径厚比 ,经原位插层聚合其片层厚度进一步被剥离为几十个纳米 ,同时原位插层聚合使得石墨粒子能够均匀分散在尼龙 6基体中 ,因而导致了该导电复合材料的低渗滤阈值和高导电性能 .     

粘土/聚烯烃纳米复合材料研究进展

原位聚合;插层复合;粘土/聚烯烃纳米复合材料研究进展     

The Research Progress of Polymer/Graphene Nanocomposites

石墨烯以其优异的力学、光学、电学和热学性能,得到日益广泛的关注和研究。本文介绍了石墨烯的结构、性能和特点,并对石墨烯的改性方法进行了概括。本文着重综述了高分子／石墨烯纳米复合材料的研究现状和进展,并介绍了高分子／石墨烯纳米复合材料的三种制备方法,即原位插层聚合法、溶液插层法和熔融插层法。此外,还对高分子／石墨烯纳米复合材料的应用前景进行了展望,并对石墨烯复合材料研究存在的问题和未来的研究方向进行了讨论。     

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…     

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结构与性能

用溶液复合法成功地制备了插层型PHBV／蒙脱土纳米复合材料。采用X射线衍射（XRD）和透射电子显微镜（TEM）研究了复合材料的结构，硅酸盐片层间距从1.8nm升至2.4nm左右。同时研究了复合材料的结晶，熔融，动态力学行为和力学性能，发现有机蒙脱土的加入，可以加快PHBV的结晶,降低熔融温度，使基体的玻璃化转变温度升高，提高了材料的力学性能，有机蒙脱土含量在3％时，其综合性能最佳。     

Structure and properties of rubber/organic montmorillonite nanocomposites prepared by in situ anionic intercalation polymerization

Polybutadiene (PB), polyisoprene (PI), and styrene–butadiene rubber/organic montmorillonite (OMMT) nanocomposites (NCs) were prepared by in situ anionic intercalation polymerization. The intercalation structure, chemical constitution, and morphology of the rubber/OMMT NCs were characterized with X‐ray diffraction, H NMR spectroscopy, and transmission electron microscopy; the thermal and dynamic mechanical properties of the rubber/OMMT NCs were characterized with differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis. The mechanical properties of PB/OMMT NC were also tested. The results showed that a certain extent of exfoliated rubber/OMMT could be prepared by anionic in situ intercalation polymerization. The incorporation of OMMT obviously changed the microstructure content of PB and PI: the concentrations of the 1,2‐unit, 3,4‐unit, and trans‐1,4‐unit increased dramatically with an increasing concentration of OMMT, and the concentration of the cis‐1,4 structure decreased. The addition of OMMT‐DK1B and OMMT‐DK4 had little effect on the molecular weight and molecular weight distribution, but the addition of OMMT‐DK1 reduced the molecular weight of rubber, and the molecular weight distribution became broad. The glass‐transition temperature, weight‐loss temperature, storage modulus, and loss modulus of the NCs evidently increased, but tan δ decreased. OMMT apparently enhanced the rubber matrix; for example, the breaking strength and hardness of PB/OMMT NC crosslinked rubber increased greatly, but the tear strength and permanent deformation did not change much. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1344–1353, 2005     

Morphology and thermal properties of polyhedral oligomeric silsesquioxane/polybutadiene nanocomposites prepared by anionic polymerization

The morphology and thermal properties of Allylisobutyl Polyhedral Oligomeric Silsesquioxane (POSS)/Polybutadiene (PB) nanocomposites prepared through anionic polymerization technique were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results of XRD, SEM and TEM showed that the aggregation of POSS in PB matrix occurred obviously, forming crystalline domains and the size of POSS particles increased with increasing POSS content. The DSC and TGA results indicated that the glass transition temperature (T _g) of the nanocomposites was significantly increased and the maximum degradation temperature (T _dmax) of nanocomposites was slightly increased compared with pure PB, implying an increase in thermal stability.     

Structure Characterization and Thermal Properties of PMMA／Montmorillonite Nanocomposites via Emulsion Polymerization

Montmorillonite(MMT) modified with sodium silicate can change the arrangement of its layers fromedge-face and edge-edge to face-face. With the fine dispersion of the modified MMT in water, the cation-ex-change reaction was carried out with cetyltrimethyl ammonium bromide (CTAB) to obtain organo-montmoril-lonite (OMMT). As OMMT was uniformly dispersed in methyl methacrylate (MMA) monomer, PMMA/OMMT nanocomposites were formed via a common emulsion polymerization. The products were extractedwith hot acetone and characterized by FTIR, molecular weight, X-ray diffraction(XRD), transmission elec-tron microscopy(TEM), DSC and TGA. These results show that most of the OMMT layers have been exfo-liated, while the thermal stability is increased obviously. By means of FTIR spectral analysis, the ratios ofthe macromolecular radicals‘ termination of disproportionation patterns to combination are increased with theaddition of OMMT. This result further confirms the increase of the thermal degradation temperatures andglass transition temperatures of the PMMA/OMMT nanocomposites.     

本质阻燃聚苯乙烯/蒙脱土纳米复合物的制备及性能

通过原位聚合法制备了本质阻燃聚苯乙烯[P(St-co-AEPPA)]/有机改性蒙脱土(OMMT)纳米复合物[P(St-co-AEPPA)/OMMT], 并用普通聚苯乙烯/有机改性蒙脱土(PS/OMMT)复合物作为对比实验, 研究了含磷、氮单体丙烯酸羟乙基-苯氧基-二乙基磷酰胺(AEPPA)和OMMT等添加物对本质阻燃聚苯乙烯性能的影响.用X射线衍射仪(XRD)和透射电子显微镜(TEM)分析了复合材料的结构与形貌, 并对OMMT在基体中的分散机理进行了讨论.用差示扫描量热仪(DSC)、热重分析(TGA)和微型量热仪(MCC)研究了材料的热性能和燃烧性能.结果表明, AEPPA和OMMT能够显著提高基体的热稳定性和阻燃性.     

Preparation and characterization of poly(propylene carbonate)/montmorillonite nanocomposites by solution intercalation

Poly(propylene carbonate) (PPC) is a new biodegradable aliphatic polycarbonate. However, the poor thermal stability and low glass transition temperatures (T_g) have limited its applications. To improve the thermal properties of PPC, organophilic montmorillonite (OMMT) was mixed with PPC by a solution intercalation method to produce nanocomposites. An intercalated-and-flocculated structure of PPC/OMMT nanocomposites was confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The thermal and mechanical properties of PPC/OMMT nanocomposites were investigated by thermal gravimetric analysis (TGA), differential scanning calorimetric (DSC), and electronic tensile tester. Due to the nanometer-sized dispersion of layered silicate in polymer matrix, PPC/OMMT nanocomposites exhibit improved thermal and mechanical properties than pure PPC. When the OMMT content is 4 wt%, the PPC/OMMT nanocomposite shows the best thermal and mechanical properties. These results indicate that nanocomposition is an efficient and convenient method to improve the properties of PPC.     

熔融法制备EVA/OMMT纳米复合材料及其热性能和动态力学性能

熔融法制备EVA/OMMT纳米复合材料及其热性能和动态力学性能;乙烯-醋酸乙烯酯共聚物;蒙脱土;动态储能模量