偶联剂对nano-ZnO/HDPE复合材料性能的影响

通过熔融共混法制备出不同硅烷偶联剂(KH550,KH560)改性的nano-ZnO/HDPE复合材料,并考察了偶联剂及ZnO含量对复合材料性能的影响。结果表明:改性nano-ZnO对HDPE基体起到了明显的增强增韧的效果,当改性nano-ZnO含量为0.2%～0.5%时,复合材料的力学性能最好。此外,nano-ZnO在HDPE中起异相成核剂的作用,从而使体系的熔融温度、结晶温度和结晶度升高。经KH560处理的nano-ZnO/HDPE复合材料的力学性能和结晶性能均优于经KH550处理的nano-ZnO/HDPE复合材料的性能。     

不同增容剂对玻璃纤维增强聚甲醛复合材料性能的影响研究

采用硅烷偶联剂γ?氨丙基三乙氧基硅烷(KH550)、γ?(2,3?环氧丙氧)丙基三甲氧基硅烷(KH560)和高分子増容剂M分别对玻璃纤维增强聚甲醛复合材料(POM/GF)进行增容改性,并通过力学性能测试、扫描电子显微镜、旋转流变仪以及差示扫描量热仪探究增容剂类型及其含量对POM/GF复合材料的力学性能、界面形貌、流变行...     

不同增容剂对PUR-T/亮氨酸复合材料性能的影响

采用硅烷偶联剂KH–560、环氧树脂E44两种不同的增容剂改性热塑性聚氨酯(PUR-T)/亮氨酸(Leu)复合材料,利用核磁共振氢谱(1H-NMR)仪、傅立叶变换红外光谱(FTIR)仪对PUR-T的结构进行表征,通过万能试验机、X射线衍射(XRD)仪和热重(TG)分析仪对复合材料的性能进行测试。结合分子模拟技术,探讨了PUR-T与Leu的界面作用。研究结果表明,FTIR谱图中出现PUR-T的特征峰,说明合成的PUR-T为目标产物,1H-NMR谱图中的化学位移也证明了这一结果。当PUR-T/Leu=80/20,KH–560,E44添加量均为1%时,两种改性复合材料的力学性能显著提高,断裂伸长率分别提高了14.7%,5.3%,拉伸强度分别提高了6.1%,7.7%。此外,KH–560和E44中的—OH与Leu中的—OH形成H—O…H—O,同时与PUR-T相互吸附,形成C=O…H—O氢键作用,促使PUR-T与Leu间的界面结合增强,KH–560和E44增容改性的PUR-T/Leu复合材料的混合能和Flory-huggins相互作用参数均低于未改性复合材料,体系可混合性明显提高。     

不同偶联剂对PA6/硬石膏粉复合材料性能的影响

采用硅烷偶联剂KH560和钛酸酯偶联剂NDZ201对硬石膏粉进行表面改性,将其与聚酰胺6(PA6)共混,利用双螺杆挤出机制备出相应的PA6/硬石膏粉复合材料,研究了不同偶联剂对复合材料力学性能、熔融与结晶行为及热稳定性的影响。结果表明:KH560和NDZ201均以化学键的形式接枝到硬石膏粉的表面;与未改性硬石膏粉相比,改性后的硬石膏粉能更好地提高复合材料的力学性能,其中KH560对硬石膏粉的表面改性效果优于NDZ201;改性前后硬石膏粉的加入,不仅提高了PA6的结晶温度和结晶度,使PA6从α晶型向γ晶型转变,还有利于提高PA6的热稳定性。     

一种高效无卤阻燃PBT复合材料的制备及性能

以次磷酸盐类复合物TF9309为主阻燃剂,三聚氰胺氰尿酸盐(MCA)为协效阻燃剂,采用增韧剂AX8900、偶联剂KH–560和30%的玻璃纤维对聚对苯二甲酸丁二酯(PBT)进行共混挤出改性,研究了无卤阻燃剂用量和不同复配比例对PBT燃烧行为和综合性能的影响,考察了增韧剂和偶联剂对复合材料力学性能的影响。结果表明,当TF9309与MCA两者复配比例为4∶1,总含量为15%,AX8900含量为2%,加入适量偶联剂KH–560时,30%玻纤增强PBT复合材料的阻燃性能和力学性能最佳。     

硅烷偶联剂改性酸性硅溶胶对PP性能的影响

研究了未改性酸性硅溶胶(Sol)、硅烷偶联剂(KH550和KH560)改性Sol作为成核剂对聚丙烯(PP)结晶行为、力学性能及光学性能的影响。结果表明:同其他两种Sol(未改性和KH560改性)相比,KH550改性Sol(Sol/KH550)对PP的异相成核作用更明显,对PP球晶具有更好的细化效果,使PP具有更优异的力学性能和光学透明性;另外在几种成核体系中,PP/Sol/KH550具有最高的结晶度、结晶温度和熔融温度,分别达到48.95%、119.87℃和163.16℃。     

高性能聚氯乙烯复合材料的研究

以聚氯乙烯(PVC)为基体、热塑性聚氨酯弹性体(PUR–T)为增韧剂、连续玻璃纤维(GF)为增强剂,通过熔体浸渍挤出工艺制备高性能PVC复合材料,并对其力学性能、耐热性能和动态力学性能进行研究。结果表明,随着PUR–T或连续GF含量增加,复合材料的力学性能和耐热性能均得到提高,当PUR–T/PVC质量比为2/8,连续GF质量分数为30%时,复合材料的拉伸强度、缺口冲击强度、弯曲强度、弯曲弹性模量、维卡软化温度分别为83.42 MPa,19.81 k J/m2,106.33 MPa,8 823.36 MPa和74.1℃;随着连续GF含量增加,复合材料的储能模量和玻璃化转变温度提高,损耗因子降低;扫描电子显微镜测试结果表明连续GF在PVC中保持了较长的长度,分散性良好。     

废胶粉、滑石粉改性PA66/GF复合材料的制备与性能

采用硅烷偶联剂KH560表面改性废胶粉(WRP)、环氧树脂E44改性滑石粉(Talc),以尼龙(PA)66/玻璃纤维(GF)复合材料为基体,制备了WRP,Talc及两者协同改性的PA66/GF复合材料,研究了WRP,Talc及两者协同作用对复合材料力学性能、结晶性能和热稳定性能的影响。结果表明,当3份WRP经过1份KH560处理后,其与PA66/GF基体间的界面粘结性明显得到改善,其改性的复合材料弯曲强度和冲击强度最高,分别比PA66/GF基体提高了11.09%和2.05%。当1份Talc经过3份E44处理后,其在基体中具有良好的分散性,改性的复合材料弯曲强度和冲击强度达到最大,分别比基体材料提高了13.89%和8.42%。WRP与Talc均能促进复合材料的结晶,但两者协同作用对复合材料结晶性能没有明显的影响。采用1份KH560处理的3份WRP协同3份E44处理的1份Talc对复合材料进行改性,可使弯曲强度和冲击强度相比基体分别提高16.97%和6.25%,且使复合材料具有良好的热稳定性能,达到了低成本WRP和Talc改性制备高性能橡塑复合材料的目的。     

PEK-CN/SiC复合材料的制备及热学性能

以酚酞聚芳醚腈酮(PEK-CN)为基体、碳化硅(SiC)为导热填料，用硅烷偶联剂(KH550,KH560及KH570)对SiC进行表面改性，通过静电纺丝技术和高温模压法制备了PEK-CN/SiC复合材料，研究了SiC含量和不同偶联剂改性SiC对PEK-CN/SiC薄膜的微观形貌、PEK-CN/SiC复合材料的导热性能和热稳定性的影响。结果表明：偶联剂改性SiC后以及随着SiC含量的增加，PEK-CN/SiC复合材料的导热性能与热稳定性均有所改善。当经KH560表面改性的SiC质量分数为25%时，复合材料的导热系数最大，达到了0.586 W/(m·K),比PEK-CN导热系数提高了133.5%,玻璃化转变温度、失重5%及30%时的温度较PEK-CN分别提升了3.79,0.37,225.76℃。     

不同软段结构对PUR–T性能影响研究

采用4,4′–二苯基甲烷二异氰酸酯为硬段,聚ε–己内酯、聚四氢呋喃醚二醇、聚乙二醇为软段,1,4–丁二醇为扩链剂合成了不同软段结构的热塑性聚氨酯弹性体(PUR–T),并用傅立叶变换红外光谱仪对其结构进行了表征,讨论了不同软段结构、不同软段分子量、不同软段浓度等因素对PUR–T力学性能和热性能的影响。结果表明,合成的PUR–T即为本研究的目标产物;PUR–T软段分子量越小其力学性能越优异,但对其热稳定性影响不大;软段结构对PUR–T的性能影响显著,其中聚酯型PUR–T的力学性能优于聚醚型PUR–T,但热稳定性较聚醚型PUR–T差;随着软段浓度的增加,PUR–T的拉伸强度和撕裂强度都呈先提高后降低的趋势,当软段浓度为60%时达到最高,PUR–T的热稳定性随软段浓度的增加而升高。     

Preparation and properties of epoxy/BN highly thermal conductive composites reinforced with SiC whisker

A simple method is reported to increase the thermal conductivity and improve the poor mechanical properties caused by high filler loadings of epoxy composites, simultaneously. Epoxy composites were prepared with micro‐boron nitride (BN) and silicon carbon whisker (SiCw) chemically treated by 3‐aminopropyltriethoxysilane (KH550) and 3‐glycidyloxypropyltrimethoxysilane (KH560), respectively. Effects of surface modification of BN particles on the thermal conductivity and flexural strength of epoxy/BN composites were investigated. About 3% SiCw particles grafted with KH560 were incorporated into composites with BN grafted with KH550, which led to about 13.8–17.8% increase of the flexural strength as well as a marginal improvement of the thermal conductivity of composites, and they possessed good dielectric properties. In addition, dynamic mechanical analysis results showed that the storage modulus of composites increased significantly with the addition of fillers, while the glass transition temperature exhibited a slight decrease. POLYM. COMPOS., 37:2611–2621, 2016. © 2015 Society of Plastics Engineers     

Effects of the content of silane coupling agent KH‐560 on the properties of LLDPE/magnesium hydroxide composites

Based on traditional idea of molecular coupling effect, surface modifiers were helpful to improve the performances of inorganic/organic composites. However, it was also widely accepted that the content of surface modifier should be controlled in a suitable range, and more or less modifiers could not reach to optimal properties. The intrinsic reason for this phenomenon was not clear until now. In this article, the influences of the content of surface modifier: silane coupling agent KH‐560, on the final performances of linear low‐density polyethylene (LLDPE)/magnesium hydroxide (MH) composites, have been studied. The performance tests of LLDPE/MH composites, including mechanical properties measurements, thermal oxidative stability analysis, and surface morphology observation, all confirmed that there was an optimal content range of surface modifier. However, further morphology investigation of the modified MH by particle size and particle size distribution analyzer showed that, the particle size and particle size distribution of MH both increased as the content of KH‐560 increased. ATR‐FTIR analysis proved that silane grafting was achieved on the MH particle surface, which not only improved the compatibility between MH and LLDPE for molecular coupling effect, but also caused bigger particle size and wider particle size distribution, which were disadvantageous to improve the performances of the composites. The two opposite effects of the surface modifiers mentioned above affected the final performances of the composites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Wood‐thermoplastic composites from wood flour and high‐density polyethylene

High‐density polyethylene/wood flour (HDPE/WF) composites were prepared by a twin‐screw extruder. The effects of WF, silane coupling agents, polymer compatibilizers, and their content on the comprehensive properties of the WF/HDPE composites have been studied in detail, including the mechanical, thermal, and rheological properties and microstructure. The results showed that both silane coupling agents and polymer compatibilizers could improve the interfacial adhesion between WF and HDPE, and further improve the properties of WF/HDPE composites, especially with AX8900 as a compatibilizer giving higher impact strength, and with HDPE‐g‐MAH as a compatibilizer giving the best tensile and flexural properties. The resultant composite has higher strength (tensile strength = 51.03 MPa) and better heat deflection temperature (63.1°C). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Evaluations of PP-g-GMA and PP-g-HEMA as a compatibilizer for polypropylene/clay nanocomposites

In this study, we investigated the performances of a hydroxy ethyl methacrylate grafted PP (PP-g-HEMA) and a glycidyl methacrylate grafted PP (PP-g-GMA) as compatibilizers in PP/clay nanocomposites. The compatibilizers were prepared by melt grafting with a radical initiator. Since the PP-g-MA is successfully and widely used in the PP/clay nanocomposites, we also studied three PP-g-MAs containing different amounts of MA and having different molecular weights for a comparison. PP/clay nanocomposites compatibilized by the PP-g-HEMA and the PP-g-GMA show a similar level of the clay interlayer distances with those of the PP-g-MAs. We also investigated the effect of molecular weights of the compatibilizers. In general, the compatibilizer of lower molecular weight was observed to exhibit lower performance as a compatibilizer. It is observed that an increase of polar group content in the modified PP (PP-g-HEMA, PP-g-GMA, and PP-g-MA) always accompanies the molecular weight reduction, which deteriorates the mechanical properties. Thus, we prepared the PP-g-HEMA and PP-g-GMA by incorporation of a styrene comonomer. The compatibilizers (PP-g-HEMA-co-styrene and PP-g-GMA-co-styrene) thus obtained show good performance as a compatibilizer in the PP/clay nanocomposites. We observed that the PP/clay composites containing the PP-g-HEMA-co-styrene and the PP-g-GMA-co-styrene have very well-balanced mechanical properties.     

Pyroelectric performances of 1-3 ferroelectric composites based on barium titanate nanowires/polyvinylidene fluoride

Pyroelectric properties of 1–3 ceramic/polyvinylidene fluoride (PVDF) composites by using barium titanate nanowires (BTnws) and dopamine modified BTnws (DM-BTnws) as inclusions were firstly reported. 0–3 composites based on dopamine modified BT nanoparticles (DM-BTnps)/PVDF were also prepared for comparison. It was found that low contents of DM-BTnws in PVDF are beneficial for achieving high fraction of β-phase content based on the analysis results of X-ray diffraction (XRD), Fourier transform infrared (FTIR) and electric displacement-electric field (D-E) measurements. The enhancement of β-phase content in the DM-BTnws/composited film was believed to originate from strong hydrogen bonds interactions between poly-dopamine and PVDF molecules, which induced phase transition in PVDF from α-phase into β-phase. However, although DM-BTnws improved β-phase content and, accordingly, pyroelectric coefficient of the composites, they deteriorated dielectric performances of PVDF, reducing pyroelectric performances of the composites in terms of voltage and detectivity figures of merit.     

相容剂对PP/PA6/nano-CaCO_3三元复合材料性能的影响

分别以PP-g-MAH和POE-g-MAH为相容剂,制备了聚丙烯/尼龙6/纳米碳酸钙(PP/PA6/nano-CaCO3)三元复合材料。研究了不同相容剂对PP/PA6/nano-CaCO3复合材料力学性能和微观结构的影响,确定了最佳相容剂及其用量。结果表明:相容剂对PP/PA6/nano-CaCO3复合材料具有良好的界面改性效果,其中POE-g-MAH的改性效果较佳。     

改性大洋黏土填充聚乙烯的力学性能研究

为确定大洋黏土的实际应用效果,对北太平洋东部的大洋黏土沉积物进行悬浮扩散提纯、硅烷偶联剂干法改性后,设计了一系列高密度聚乙烯填充实验,利用冲片机制备相应的聚乙烯复合材料进行拉伸实验,结果表明:复合材料的拉伸强度和断裂伸长率随着黏土用量的增加呈现完全相反的变化趋势,填充效果较好的黏土用量约为2%,双辊混炼的效果略胜于单螺杆挤出;同时,添加相容剂和抗氧剂对于改善复合材料力学性能的意义不大。     

高密度聚乙烯／蒙脱土纳米复合材料的制备与性能研究

采用马来酸酐接枝乙烯醋酸乙烯酯（EVA-g-MAH）和马来酸酐接枝低密度聚乙烯（PE-LD-g-MAH）为相容剂，制备了高密度聚乙烯傣脱土（PE-HD／MMT）纳米复合材料。用X射线衍射和扫描电镜对有机蒙脱土和PE-HD／MMT复合材料的结构进行了表征，研究了蒙脱土和相容剂含量对制备的纳米复合材料力学性能及热性能的影响。结果表明，相容剂的加入有利于插层。MMT在复合材料中呈纳米级分散。其层间距可由2．10nm增大至3．85nm。MMT含量为3％（质量分数，下同）、EVA-g-MAH含量为15％时，复合材料的综合力学性能最好，冲击强度和拉伸强度分别较PE-HD提高43．7％和5.8％。