聚酰胺6/蒙脱石纳米复合材料的紫外光老化

聚合物 /层状硅酸盐纳米复合材料的研究十分活跃 [1～ 4 ] .聚酰胺 6/蒙脱石 ( PA6/MMT)纳米复合材料与纯聚酰胺 6( PA6)相比 ,模量和强度明显提高 ,耐热性能提高尤为显著 .光氧化行为材料科学领域的重要研究课题 .Admas等 [5]报道在紫外光照射下 ,聚丙烯 /粘土纳米复合材料的氧化速度要比纯聚丙烯的快 .对于 PA6/MMT纳米复合材料的光老化研究尚未见报道 .本文以傅里叶变换红外光谱定量研究手段 ,对比分析了 PA6/MMT纳米复合材料与 PA6的紫外光氧化性能 .1　实验部分　　采用熔体插层技术 ,将 PA6( Honeywell B1 0 0 MP)和有机蒙…     

PA6/HIPS/PP-g-(GMA-co-St)反应共混体系的研究

通过扫描电镜、热分析、熔体流动速率、熔融扭矩和力学性能等测试方法研究了甲基丙烯酸缩水甘油酯(GMA)和苯乙烯(St)多单体熔融接枝聚丙烯[PP-g-(GMA-co-St)]对PA6/HIPS共混物的熔融流变性能、结晶行为、相形态和力学性能的影响.结果表明,在熔融共混过程中,PP-g-(GMA-co-St)中的环氧基与PA6的端氨基原位生成的接枝共聚物有效地降低了共混物的界面张力,提高了共混物的界面粘着力,使共聚物的流动速率降低,熔融扭矩提高;PA6分子链的规整性降低,结晶完善性变差.在PP-g-(GMA-co-St)的质量分数为10%时,共混物分散相的尺寸明显减少,力学性能得到较大提高;其中冲击强度超过纯PA6,达到HIPS水平.通过反应共混,制备了力学性能均衡的PA6/HIPS/PP-g-(GMA-co-St)共混物合金.     

滑石粉及混炼顺序对PA6/PP/MAPP合金相形态及力学性能的影响

通过挤出和注射成型制备了滑石粉(Talc)填充的尼龙6/聚丙烯/马来酸酐接枝聚丙烯(PA6/PP/MAPP)合金, 研究了Talc和混炼顺序(一步法和PA6母料法)对合金相形态和力学性能的影响. 场发射扫描电镜(FESEM)分析结果表明, 添加Talc后注射样条中心部分的PP相由球状转变为沿流动方向取向的有分支的条状结构, 且用PA6母料法制样比用一步法制样的相形态更为精细. 溶解PA6相后对PP相进行热重分析(TGA), 确定了Talc在PA6相和PP相中的分布比例, Talc选择性分布于PA6相中. PA6母料法中Talc的分散好于一步法. 研究了材料的拉伸、 弯曲、 冲击、 热变形温度和动态力学性能, Talc的添加能够明显提高材料的刚性, 且母料法样品的性能优于一步法样品.     

高温尼龙PA10T改性研究最新进展

聚对苯二甲酰癸二胺(PA10T)是我国自主开发的一种新型生物基耐高温尼龙,具有优异的力学性能、耐热性、耐磨性、尺寸稳定性、耐化学腐蚀性、抗水解性和良好的加工性能,且吸水率低,应用前景广阔,是近几年发展较快的一种特种工程塑料。对PA10T的改性研究一直是学术界和产业界关注的重点,本文综述了2015——2020年间国内外关于PA10T改性研究最新发展情况。主要从制备方法(原位共聚、熔融共混、协同改性)和性能(结晶、力学、热氧老化、阻燃、流变、透光和综合性能)等方面重点阐述,详细分析了PA10T科研和产业发展现状,并展望了PA10T的未来改性发展方向和潜在应用领域。     

PP-g-(GMA-co-St)对PA6/PC共混物的反应增容作用

用红外、扫描电镜、熔体流动速率和力学性能等测试方法,研究了甲基丙烯酸缩水甘油酯(GMA)和苯乙烯(St)多单体熔融接枝聚丙烯[PP-g-(GMA-co-St)]对PA6/PC共混物的反应增容作用.研究结果表明,在熔融共混过程中,PP-g-(GMA-co-St)中的环氧基与PA6的端氨基及PC的端羟基原位生成的接枝共聚物有效地降低了共混物相间的界面张力,明显提高了共混物相界面的粘着力.少量的PP-g-(GMA-co-St)就能使PA6和PC的相容性得到显著改善.当PP-g-(GMA-co-St)的质量分数为10%时,共混物分散相的相区尺寸细化到0.2μm,其力学性能也有较大提高.PA6/PC/PP-g-(GMA-co-St)共混物的力学性能均衡,达到了弹性体增韧体系难以达到的效果.即使PP-g-(GMA-co-St)组分含量为20%时,共混物仍能保持较好的力学性能,特别是在共混物的韧性得以提高的同时,其强度和伸长率也提高.     

室温离子液体催化合成碳酸丙烯酯

碳酸丙烯酯(PC)是一种性能优良的高沸点高极性有机溶剂,在有机合成、化妆品、气体分离、电池介电质[1]及金属萃取[2]等领域得到广泛的应用. 近年来,许多尿素生产厂家将其用作脱碳剂,使其需求量大增. PC合成方法主要有光气法、酯交换法、氯丙醇法及环氧丙烷(PO)与CO2环加成等. 其中, 以PO与CO2为原料环加成制PC是一条低污染、环境友好的路线. 已报道的用于PO与CO2环加成的催化剂有碱、季铵盐、金属盐[3]、配合物[4～6]以及MgO[7], MgO-Al2O3[8], KI/ZnO[9],KI/冠醚和KI/聚乙二醇[10]等. 尽管品种繁多,但仍存在催化剂活性不高,产物分离及催化剂回收困难等问题.     

氯化镁/氯化1-丁基-3-甲基咪唑改性淀粉/聚丁二酸丁二醇酯共混材料的结构与性能

用氯化镁/氯化1-丁基-3-甲基咪唑([BMIM]Cl)复合增塑剂改性淀粉/聚丁二酸丁二醇酯(PBS)共混材料,采用红外光谱(FTIR)、扫描电子显微镜(SEM)、差示扫描量热分析(DSC)、X射线衍射分析(XRD)及力学性能测试等方法研究了氯化镁/[BMIM]Cl改性淀粉/PBS共混材料的结构和性能.结果表明,氯化镁能与淀粉及PBS形成较强的相互作用,从而破坏淀粉及PBS原有的氢键,导致淀粉/PBS共混体系结构和性能的改变.与[BMIM]Cl改性体系相比,氯化镁/[BMIM]Cl改性体系能进一步增强淀粉与PBS的界面结合力,提高共混体系的相容性;使淀粉/PBS的熔融焓、结晶度及结晶温度降低,冷结晶温度升高;提高共混体系的力学强度和断裂伸长率,抑制[BMIM]Cl因高效增塑产生的强度降低作用.采用氯化镁/[BMIM]Cl改性淀粉/PBS可制备出具有良好力学性能的淀粉/PBS共混材料.     

sPS/PA6/蒙脱土纳米复合材料的制备与性能

讨论了间规聚苯乙烯 (sPS) 尼龙 6(PA6) 磺化间规聚苯乙烯 (SsPS H) 蒙脱土纳米复合材料的制备技术和新材料的结构与性能特征 .蒙脱土经层间改性处理后 (MTN) ,可分别将SsPS H和aPS(无规聚苯乙烯 )插入其纳米层间 ,制备出插层型纳米复合物MTN SsPS和MTN aPS .在sPS/PA6/SsPS H三组分共混体系中加入MTN SsPS或MTN aPS ,进行四组分熔融共混即可制备出sPS/PA6/SsPS H/蒙脱土纳米复合材料 .TEM测定证实了蒙脱土在基体中的层厚分布约为 5 0nm .此外 ,采用DSC、DMA、XRD及力学性能测试仪等现代分析方法对sPS/PA6/SsPS H/蒙脱土纳米复合材料的结构与性能进行了详细研究 .研究结果表明这种纳米复合材料具有优良的综合性能     

酸碱处理蒙脱土与磷酸酯阻燃剂复配阻燃PC/ABS合金

采用酸碱处理法对蒙脱土进行有机化改性, 再将酸碱处理的蒙脱土与磷酸酯阻燃剂复配, 作为聚碳酸酯/丙烯腈-丁二烯-苯乙烯三元共聚物(PC/ABS)合金的阻燃体系, 并表征了酸碱处理蒙脱土对合金的热稳定性和阻燃性能. 结果表明, 间苯二酚双(二苯基磷酸酯)改性的蒙脱土(BDP-MMT)使阻燃PC/ABS合金的起始分解温度降低, 而酸碱处理蒙脱土却使合金的起始分解温度有所提高; BDP-MMT的加入会恶化碳层的阻隔性能, 而酸碱处理蒙脱土却可以增加碳层的稳定性, 使第二热释放峰值出现的时间延迟, 且适合的酸浓度处理蒙脱土可以使合金通过UL-94 V-0级检验.     

硅烷改性纳米ZrO2对镁锂合金表面环氧树脂涂层耐蚀性能的影响

采用涂覆法在镁锂合金表面制备了含双-[3-(三乙氧基硅)丙基]四硫化物(KH-69硅烷)改性纳米ZrO₂的环氧树脂涂层. 通过傅里叶变换红外光谱(FTIR)、 扫描电子显微镜(SEM)和电化学阻抗谱(EIS)等手段表征了该涂层. 考察了KH-69硅烷改性纳米ZrO₂浓度对环氧树脂涂层耐蚀性能的影响. 结果表明, KH-69硅烷改性纳米ZrO₂能显著提高镁锂合金表面环氧树脂涂层的耐腐蚀性能, 其中1.0%(质量分数) KH-69硅烷改性纳米ZrO₂环氧树脂涂层具有较好的耐蚀性能. 在NaCl溶液中浸渍528 h后的低频阻抗值为1.6×10⁹ Ω·cm², 相比在NaCl溶液中浸渍240 h的纯环氧树脂涂层提高约5个数量级.     

界面改性剂对刚性粒子增韧尼龙6熔体流变行为的影响

研究了界面改性剂对高岭土增韧尼龙６熔体流变行为的影响,并与硅烷偶联剂ＫＨ５５０进行了比较．结果表明,ＫＨ５５０的加入明显降低了高岭土填充尼龙６熔体的粘度和弹性,而界面改性剂显著地增强了它的粘度和弹性．这一差别应归因于同ＫＨ５５０相比,界面改性剂更有效地增强了高岭土与尼龙６基体之间的界面结合和其自身的回弹性能．同时,界面改性剂的用量对高岭土填充尼龙６流变行为具有很大影响．当界面改性剂的用量为高岭土和尼龙６总量的２％时,界面改性剂在高岭土表面上趋于“饱和”,再增加界面改性剂的用量,对流变行为的影响不大．     

Preparation of core‐shell structured particle and its application in toughening PA6/PBT blends

Combining the excellent mechanical strengths of polyamide 6 (PA6) with the low water absorption of poly(butylene terephthalate) (PBT) was supposed to be a feasible way to prepare a high comprehensive performance material. However, the poor compatibility between PA6 and PBT resulted in low‐notched impact strength of PA6/PBT blends. Poly(n‐butyl acrylate)/poly(methyl methacrylate‐co‐methacrylic acid) (PBMMA), a core‐shell structured modifier with controlled particle sizes, was prepared by seed emulsion polymerization and confirmed by Transmission electron microscope (TEM). The PBMMA particles as toughening modifier and compatilizer were employed to toughen PA6/PBT blends. The notched impact strength of the PA6/PBT blends was significantly increased and the water absorption was reduced with the addition of PBMMA particles. With 23.0 wt% modifier loading, the notched impact strength of the blends was 25.66 kJ/m², which was 4.04 times higher than that of pure PA6/PBT. Meanwhile, the water absorption of the blends was only 1.3%, dropping 53.6% compared with pure PA6 and reducing by 26.6% than PA6/PBT. Scanning electron microscope results showed that the PBMMA particles were dispersed in the PA6/PBT blends homogeneously, and the toughening mechanism was the cavitation of rubber particles and shear yielding of the matrix. Thermo‐gravimetric analysis analysis demonstrated that the compatibility between PA6 and PBT was improved with the addition of core‐shell PBMMA particles. The core‐shell particles could be used as an effective modifier to achieve the high toughness and low water absorption for PA6/PBT blends. Copyright © 2016 John Wiley & Sons, Ltd.     

PA‐6 and EVA alloy/clay nanocomposites as char forming agents in poly(propylene) intumescent formulations

This study investigates the influence of nylon‐6 (PA‐6) and ethylene‐vinyl acetate copolymer (EVA) alloy/clay nanocomposites on the properties of the flame‐retardant (FR) poly(propylene). Cone calorimetry and scanning electron microscopy (SEM) techniques were used to investigate the effect of PA‐6 and EVA alloy nanocomposites on the fire properties and dispersion of intumescent flame‐retardants (IFRs). The experimental results show that PA‐6 and EVA alloy nanocomposites improve the fire and mechanical properties of the FR poly(propylene). It is also shown that the improvement of the properties mainly depends on the weight ratio of PA‐6 and EVA in the alloys. The probable mechanisms are discussed in this paper. Copyright © 2005 John Wiley & Sons, Ltd.     

INTERFACIAL MOLECULAR DESIGN OF A RIGID- PARTICLE TOUGHENED POLYAMIDE 6 COMPOSITE

The effects of interfacial modifier on the mechanical properties of kaolin-filled polyamide 6 (PA6) have been studied. The interracial interaction between polyamide 6 and kaolin has been character ized by means of infrared spectroscopy (IR) and scanning electron microscopy (SEM). The results show that the role of the interracial modifier lies in forming an elastic interlayer with good adhesion between kaolin and PA 6. A composite with high impact strength, high tensile strength and high elastic modulus can be obtained by inserting the elastic interfacial modifier into the rigid-particle-filled polymer system.     

PP/PP-g-MAH/PA6共混物结构与可纺性研究

运用DSC、SEM、纺丝成形等手段研究了增容剂聚丙烯接枝马来酸酐 (PP g MAH)对聚丙烯 聚酰胺 6(PP PA6 )共混物结构和性能的影响 .结果表明 ,共混物呈典型海岛型两相结构 ;增容剂PP g MAH与PA6之间的在位反应改善了PP PA6共混体系的相容性 ,使共混物中PA6的热结晶峰消失 ,PP的结晶生长速率和成核速率降低 ,可纺性提高     

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...     

Maleic Anhydride Polyethylene Octene Elastomer Toughened Polyamide 6/Polypropylene Nanocomposites: Mechanical and Morphological Properties

A series of polyamide 6/polypropylene (PA6/PP) blends and nanocomposites containing 4 wt% of organophilic modified montmorillonite (MMT) were designed and prepared by melt compounding followed by injection molding. Maleic anhydride polyethylene octene elastomer (POEgMAH) was used as impact modifier as well as compatibilizer in the blend system. Three weight ratios of PA6/PP blends were prepared i.e. 80:20, 70:30, and 60:40. The mechanical properties of PA6/PP blends and nanocomposite were studied through flexural and impact properties. Scanning electron microscopy (SEM) was used to study the microstructure. The incorporation of 10 wt% POEgMAH into PA6/PP blends significantly increased the toughness with a corresponding reduction in strength and stiffness. However, on further addition of 4 wt% organoclay, the strength and modulus increased but with a sacrifice in impact strength. It was also found that the mechanical properties are a function of blend ratio with 70:30 PA6/PP having the highest impact strength, both for blends and nanocomposites. The morphological study revealed that within the blend ratio studied, the higher the PA6 content, the finer were the POEgMAH particles.     

Preparation of ZnO nanoparticle‐reinforced polyamide 6 composite by in situ‐coproduced method and their properties

Polyamide 6/ZnO nanocomposites (noted as PA6/ZnO) were prepared by an in situ co‐producing method, during which Zn₂(OH)₂CO₃ decomposed into nano‐ZnO in the process of the opening‐ring polymerization of caprolactam at high temperature. Transmission electron microscopy, X‐ray diffraction, thermogravimetric analysis, and differential scanning calorimetry were used to analyze the size and dispersive properties of nano‐ZnO, the crystallization and melting properties, the thermal properties, and crystal structure of PA6/ZnO composite, respectively. The results showed that the nano‐ZnO derived from Zn₂(OH)₂CO₃ via in situ polymerization of PA6‐ZnO was uniformly dispersed in PA6 matrix. However, the overall nano‐ZnO crystallization rate and crystal size in the PA6 matrix were hindered by the bulky PA6 molecular chains. The mechanical properties were evaluated using universal tensile and impact testing instruments. The results revealed that PA6/ZnO composite with 0.2% nano‐ZnO content possessed excellent tensile strength, enhanced by 75% in comparison with the pure PA6. The nano‐ZnO had little influence on the impact strength of PA6. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 165–170