HIPS／改性氢氧化镁晶须复合材料的研究

采用乙烯基硅烷在氢氧化镁(MH)晶须表面引入乙烯基后与苯乙烯进行原位聚合,得到了聚苯乙烯改性的氢氧化镁晶须(MMH).将MMH与高抗冲聚苯乙烯(HIPS)熔融复合制备了HIPS/MMH复合材料,研究了复合材料的微观结构和力学性能.结果表明,聚苯乙烯包覆在MH表面,并形成了共价键结合;原位聚合改性改善了MH在HIPS基体中的分散性,增强了MH和HIPS的界面相互作用,显著提高了HIPS/MMH复合材料的拉伸强度与冲击韧性.     

玻璃纤维改性尼龙复合材料现状

玻璃纤维(GF)改性尼龙(PA)复合材料是一种高性能工程塑料,其应用范围十分广泛。对影响PA/GF复合材料性能的重要因素进行综述。阐述了GF与PA基体界面作用力、GF的直径、挤出机螺杆组合及GF与其他无机填料的协同作用对PA/GF复合材料性能的影响规律。结果表明,对GF进行有机化改性或在PA基体中添加其他改性剂能显著提升PA和GF界面作用力,从而提高PA/GF复合材料的力学性能。GF的直径越小,PA/GF复合材料的力学性能越好。螺杆组合对PA/GF复合材料中GF的长度和分散性具有重要影响,联合使用齿形盘、反向齿形盘与啮合块,制备的PA/GF复合材料性能更好。与单独采用GF改性的PA复合材料相比,当其他无机填料与GF协同使用时,PA/GF复合材料的力学性能较好。最后,对未来GF改性PA复合材料的研究方向进行了展望。     

玻璃纤维增强尼龙6的研究进展

优化玻璃纤维(GF)的种类和用量、尼龙6(PA6)与GF的复合工艺,改善PA6与GF的界面结合情况,均有利于改进PA6/GF复合材料的性能。利用第三组分和GF对PA6进行协同改性也是改善PA6/GF复合材料性能的重要手段。综述了PA6/GF复合材料性能的影响因素、复合材料的复合工艺、界面处理方法和第三组分与GF对PA6的协同改性等方面的研究进展。     

原位聚合改性滑石粉/PP复合材料的微观结构和力学性能

通过熔融共混制备了丙烯酸丁酯(BA)原位聚合改性滑石粉/聚丙烯(PP)复合材料。研究了原位聚合改性对滑石粉/PP复合材料形貌、晶型结构、结晶熔融行为和力学性能的影响。结果表明,PP和滑石粉在熔融共混过程中,剪切力的作用使层叠的滑石粉剥离成不同厚度的片层,BA原位聚合改性改善了滑石粉与PP之间的界面粘结,有利于滑石粉在PP基体中的剥离;滑石粉的原位聚合改性,促进了β-晶型PP的生成,提高了滑石粉/PP复合材料中PP相的熔点、结晶速率和结晶度,降低了PP相的结晶温度。同时显著提高了滑石粉/PP复合材料的冲击强度,且存在一最佳的BA用量。     

GF增强PP/苎麻纤维复合材料的制备及其性能研究

采用非织造-模压工艺,以苎麻纤维为增强体和聚丙烯(PP)纤维制备了PP/苎麻纤维复合材料,然后添加玻璃纤维(GF)对PP/苎麻纤维复合材料进行增强改性。分别研究了不同含量苎麻纤维、GF对复合材料弯曲性能、剪切性能及吸水性能的影响,并采用扫描电子显微镜(SEM)研究了改性前后复合材料界面结合的微观形貌变化。结果表明,当PP/苎麻纤维复合材料中苎麻纤维体积分数为40%时,复合材料的弯曲、剪切性能最优;当添加体积分数为5%的GF和35%的苎麻纤维时,PP/GF/苎麻纤维复合材料弯曲强度、弯曲弹性模量、层间剪切强度分别增加18.48%,10.22%和31.41%,且复合材料吸水率最小。     

梯度GF/SAN复合材料的制备

酸性条件下，使用强氧化剂、正硅酸乙酯（TEOS）和苯基三乙氧基硅烷（PTES）依次对短玻璃纤维（GF）表面进行改性，制备了梯度GF／苯乙烯-丙烯腈共聚物（SAN）复合材料，利用光学显微镜和红外光谱（FTIR）对梯度GF和普通GF进行了对比分析。结果表明，改性后的GF表面形成了由无机相向有机相逐渐过渡的梯度结构，GF／SAN复合材料冲击强度测试和断面的场发射扫描电镜（FESEM）分析表明梯度GF与SAN树脂具有很好的相容性和更好的冲击性能。     

偶联剂对玻纤增强PP复合材料力学性能的影响

选取5种不同型号的偶联剂,采用湿法改性对玻纤表面进行处理,制备聚丙烯/玻纤(PP/GF)复合材料。通过PP/GF的界面行为表征,分析了不同偶联剂对PP/GF复合材料的影响规律。结果表明:GF经偶联剂改性的PP/GF复合材料与未改性的相比,材料力学性能得到大幅度提高。其中以偶联剂KH560改性效果最理想,拉伸强度达到59.14 MPa,压缩强度为70.69 MPa,冲击强度为10.14 kJ/m2。     

增容剂对GF增强SAN复合材料性能的影响

玻璃纤维(GF)增强苯乙烯-丙烯腈塑料(SAN)复合材料采用熔体浸渍工艺制备,研究了不同增容剂对GF增强SAN复合材料性能的影响。结果表明,添加增容剂的GF增强SAN复合材料的缺口冲击强度、拉伸强度和弯曲强度均有提高,加入增容剂苯乙烯-丙烯腈接枝甲基丙烯酸缩水甘油酯(SAG)时,复合材料的综合性能最优,其缺口冲击强度、拉伸强度和弯曲强度分别为23.09 k J/m2,103.48 MPa,174.92 MPa;复合材料的储能模量最大,损耗因子峰值最小。加入SAG的GF增强SAN复合材料的相容性比加入苯乙烯接枝马来酸酐(SMA)的复合材料的好。扫描电子显微镜分析表明,GF增强SAN复合材料中的GF没有被拔出,且表面包覆一层基体树脂。     

PA66/GF复合材料研制及应用

研究了不同单纤维直径的玻璃纤维(GF)增强尼龙(PA)66复合材料的力学性能,通过扫描电子显微镜研究了PA66/GF复合材料的微观形貌结构.结果表明,GF直径减小,其与PA66的界面结合程度变好,PA66/GF复合材料的力学性能逐渐提高,但增幅不尽相同,直径为11 μm的GF制得的PA66/GF复合材料的力学性能与GF直径为10 μm的力学性能相当、微观结构也相似.采用直径为11 μm的GF制得的PA66/GF复合材料具有更高的性价比,已广泛应用于汽车行业.     

聚酰胺6/纳米二氧化硅复合材料的制备和界面研究

采用原位聚合法制备了聚酰胺6/纳米二氧化硅（PA6/nano-SiO2）复合材料,用力学性能测试、 扫描电镜和差示扫描量热法对纳米SiO2粒子和PA6基体之间的界面黏结性进行了表征和研究。结果表明：利用经验公式和力学性能数据计算得知PA6/改性SiO2纳米复合材料的界面参数B值都比PA6/未改性SiO2纳米复合材料的大;SEM观察表明在PA6中加入纳米SiO2,材料的微观结构发生了变化,改性SiO2与PA6基体之间形成了较好的界面结合;分散于PA6基体中的纳米SiO2粒子起到了异相成核作用,改性后的SiO2和PA6基体之间形成柔性界面层有利于PA6基体的结晶。     

界面改性方法对玻纤增强聚丙烯复合材料力学性能的影响

在对玻璃纤维的偶联剂处理,基体接枝改性的基础上,考察不同界面改性方法对玻纤增强聚丙烯力学性能的影响,并通过扫描电镜对玻纤增强聚丙烯的界面进行研究。结果表明,经偶联剂表面处理的玻纤与未经接枝改性的聚丙烯不能形成有效的界面粘结,力学性能较差,而与接枝改性的聚丙烯界面粘结较好,力学性能也有较大幅度的提高;经偶联剂处理的玻纤能与改性聚丙烯形成良好的界面粘结,改善复合材料的力学性能,偶联剂种类的变化在一定程度上能够改善复合材料的性能。     

聚丙烯/玻璃纤维的界面改性研究(Ⅲ)界面改性的复合效应

研制高性能的玻璃纤维增强聚丙烯复合材料的关键是提高非极性的聚丙烯和极性的玻璃纤维的界面粘结强度。我们认为双马来酰亚胺与聚丙烯 -马来酸酐接枝共聚物并用具有较好的协同效应 ,这与它们之间形成了某种IPN结构有关 ,IPN结构的形成强化了聚丙烯基体的强度 ,也强化了玻璃纤维与聚丙烯基体的界面粘结 ,从而最大程度地提高了复合材料的力学性能     

Effective surface treatments for enhancing the thermal conductivity of BN‐filled epoxy composite

To improve the thermal conductivity of BN‐filled epoxy composite, admicellar polymerization was used to coat polystyrene and polymethyl methacrylate on the BN surface to improve the interfacial adhesion in the composite. The treated surface was characterized by FTIR and contact angle measurements. The results show that the admicellar treatment led to improved wettability of epoxy resin on the treated surface. Thermal conductivity of the composite increased from 1.5 W/mK for untreated BN to 2.69 W/mK when the admicellar‐treated BN was used, indicating improvement in the interfacial adhesion between BN and epoxy resin in the composite. The mechanical properties of the composite also improved significantly. The surfactant : monomer molar ratio of 1 : 10 was found to be the optimum condition for the admicellar polymerization process. The solubility parameter concept was used to explain the difference in the effectiveness of polystyrene and polymethyl methacrylate. When compared to the more conventional silane treatment, admicellar treatment was found to be more effective in improving the interfacial adhesion between the BN particles and epoxy resin. SEM micrographs of the fractured surface of the composite further confirm the improvement in the interfacial adhesion after the admicellar treatment. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

原位聚合PLA/HA复合材料的性能研究

采用原位聚合法和超声波辅助分散溶液共混法，分别制备了羟基磷灰石质量分数为30％的聚乳酸（PLA）／羟基磷灰石（HA）生物可降解复合材料，对其结构与力学性能进行了研究。结果表明，HA的存在对乳酸的聚合有一定的影响，使其摩尔质量降低、分布变宽。与共混法相比，原位聚合法改善了HA在复合材料中的分散性，在PLA与HA之间形成了较强的结合界面，从而提高了PLA玻璃化温度和力学性能。     

聚丙烯/玻璃纤维的界面改性研究(Ⅳ)--玻璃纤维增强聚丙烯复合材料的界面结构特征

研制高性能的玻璃纤维增强聚丙烯复合材料的关键是提高非极性的聚丙烯和极性的玻璃纤维的界面粘结强度。文章运用溶剂抽提ＦＴ－ＩＲ、ＤＳＣ、ＳＥＭ等分析测试手段对ＦＲＰＰ的理化性能进行了表征,提出玻璃纤维增强聚丙烯复合材料体系的最突出的界面特征是界面剂接枝物与玻璃纤维的相互作用和界面剂接枝物与聚丙烯基体树脂的共结晶。     

Oligomer and random copolymer layer in relation to enhancement of interfacial adhesion at polystyrene/poly(styrene‐co‐acrylonitrile) interface

This study examines the interfacial adhesion between poly(styrene) (PS) and poly(styrene‐co‐acrylonitrile) (SAN) interfaces reinforced with poly(styrene‐co‐vinyl phenol) (PS‐ran‐PSPh) random copolymers using an asymmetric double‐cantilever beam (ADCB) test. The effects of oligomer and copolymer composition on interfacial adhesion were investigated. The results showed that the interfacial adhesion of the PS/SAN interface was increased significantly after removing the residual oligomer from the SAN. The interfacial adhesion was also measured for five‐purified SAN materials in the range 17–31 wt%. The highest level of PS/SAN adhesion was observed for 17% AN (acrylonitrile) materials. In addition, the interfacial adhesion of a mixture of diblock and random copolymer was measured in order to investigate which is the most effective method. The results showed that mixture systems are more cost‐effective with higher adhesion, which is independent of temperature. Atomic force microscopy showed that a single craze ahead of the crack is a possible failure mode during PS/SAN interface fracture. Copyright © 2004 Society of Chemical Industry     

Largely enhanced crystallization of semi-crystalline polymer on the surface of glass fiber by using graphene oxide as a modifier

Interfacial crystallization of polymer on the surface of filler not only offers crystallography interest but also has a potential to improve the interfacial interaction, which is a key for the preparation of high-performance polymer/filler composites. In this work, a new method is proposed to improve the interfacial crystallization between semi-crystalline polymer and glass fiber (GF) by introducing graphene oxide (GO) to the surface of amorphous GF. The coating of GO on GF surface is realized via electrostatic self-assembling of the oppositely charged GO and amino coupling agent modified GF (GF-NH₂). After the thermal reduction of the coated GO (RGO), RGO coated GF (GF-RGO) is obtained. The interfacial crystallization of isotactic polypropylene (iPP) and poly(l-lactide) (PLLA) on the surface of raw GF, GF-NH₂, and GF-RGO are investigated using Polarized light microscope (PLM). It is found that raw GF and GF-NH₂ has almost no nucleation ability on the polymers crystallization. However, transcrystalline structure can be successfully induced at the polymers/GF-RGO interface, indicating a significantly improved nucleation ability of GF-RGO for polymer crystallization. This work could provide a new way to control interfacial crystallization, thus the interfacial adhesion of polymer/filler composites, and could also find a new application for GO as well.     

Biofiber-reinforced polypropylene composites

Biofibers, natural lignocellulosics, have an outstanding potential as a reinforcement in thermoplastics. This study deals with the preparation of lignocellulosic composites by reactive extrusion processing in which good interfacial adhesion is generated by a combination of fiber modification and matrix modification methods. PP matrix was modified by reacting with maleic anhydride and subsequently bonded to the surface of the modified lignocellulosic component, in-situ. The fiber surface was modified by reacting it with a silane in a simple and quick aqueous reaction system, similar to that employed for glass fibers. The modified fibers are then extruded with the modified polymer matrix to form the compatibilized composite. The various reactions between the lignocellulosic fiber/filler and modified polymer chains, is expected to improve the interfacial adhesion significantly as opposed to simple mixing of the two components, since new covalent bonds between the fiber surface and matrix are created in the former case. These composite blends were then injection molded for mechanical characterization. Typical mechanical tests on strength, toughness and Izod impact energy were performed and the results are reported. These findings are discussed in view of the improved adhesion resulting from reactions and enhanced polar interactions at phase boundaries.     

热压成型聚丙烯/玻璃纤维复合膜的结构及力学性能

将酸刻蚀后的玻璃纤维（GF）网引入聚丙烯（PP）基体,通过热压成型技术制备PP/GF复合膜。综合利用X射线衍射仪、差示扫描量热仪、扫描电子显微镜和万能材料试验机对PP/GF复合膜的结晶结构、热行为、界面结合形态和力学性能进行表征分析,重点讨论GF含量对微结构及性能的影响。结果表明,经酸刻蚀后GF表面形成许多沟槽,粗糙度增大,提高了GF与PP基体间的界面结合强度;GF网的引入使成核点增多,结晶度增加;GF含量较低时,PP/GF复合膜的力学性能与PP相比显著提高,GF含量为0.2 %（质量分数,下同）时,PP/GF复合膜的拉伸强度和断裂韧性分别提高了33.75 %和41.15 %;随GF含量的增加,拉伸强度和断裂韧性呈减小的趋势。     

Preparation and mechanical properties of poly(vinyl chloride)/bamboo flour composites with a novel block copolymer as a coupling agent

To improve the interfacial adhesion between poly(vinyl chloride) (PVC) and bamboo flour in PVC/bamboo flour composites, a novel coupling agent, poly(styrene‐co‐maleic anhydride)‐block‐poly(styrene‐co‐acrylonitrile) {P[(SMA)‐b‐(SAN)]}, was synthesized through living free‐radical polymerization in a one‐pot reaction. P[(SMA)‐b‐(SAN)] was synthesized by a nitroxide‐mediated polymerization technique in the presence of 2,2,6,6‐tetramethylpiperidin‐l‐oxyl with azobisisobutyronitrile. The conversion of maleic anhydride (>99%) and styrene (>65%) was relatively high and yielded P[(SMA)‐b‐(SAN)] with a narrow molecular weight distribution (weight‐average molecular weight/number‐average molecular weight <1.38). PVC was blended with bamboo flours in the presence of the synthesized coupling agent with a two‐roll mill. P[(SMA)‐b‐(SAN)] was added to the PVC matrix at a concentration of 55 or 20 wt %. As the content of P[(SMA)‐b‐(SAN)] in the wood–polymer composite increased, improved morphological and mechanical behaviors were observed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008