聚丙烯/纳米钛合金复合材料力学性能的研究

将经有机化处理的纳米钛合金粉体与聚丙烯通过熔融共混制得了聚丙烯/纳米钛合金复合材料;利用XRD对聚丙烯及其复合材料的结晶形态以及复合材料中钛合金粉体的粒径进行了分析;研究了钛合金粉体对复合材料拉伸模量、拉伸强度、断裂伸长率、冲击强度及屈服强度的影响。结果显示,纳米钛合金粉体的加入有利于聚丙烯基体形成具有良好冲击强度的β型晶体;在钛合金粉体用量适当时,复合材料的拉伸模量、拉伸强度、断裂伸长率和冲击强度均有所提高,其中冲击强度和断裂伸长率提高尤其显著。     

高性能芳纶浆粕/HNBR复合材料的制备及性能研究

试验研究预处理方法对芳纶浆粕在橡胶基体中分散性及芳纶浆粕／HNBR复合材料性能的影响。结果表明，芳纶浆粕预处理改善了其在复合材料中的分散效果；白炭黑预处理复合材料的定伸应力和拉伸强度提高，拉断伸长率减小，高温下物理性能稍有改善；共沉法预处理改善效果不明显；白炭黑预处理芳纶浆粕用量增大，混炼时间不变，复合材料物理性能提高，但高温下撕裂强度减小；芳纶浆粕／HNBR复合材料中，芳纶浆粕容易取向；芳纶浆粕用量增大，复合材料挤出性能改善。     

马来酸酐化液体聚丁二烯对天然橡胶/芳纶短纤维复合材料性能的影响

研究马来酸酐化液体聚丁二烯(MLPB)对芳纶短纤维(SAF)补强天然橡胶(NR)复合材料性能的影响。结果表明:SAF和炭黑对NR的补强有协同作用,加入相容剂MLPB提高了橡胶基体与纤维的界面粘合性能,复合材料静态和动态力学性能明显提高;随着MLPB用量的增大,复合材料100%定伸应力增大,拉伸强度、拉断伸长率和撕裂强度在MLPB用量为4.5份时达到最大值。     

短纤维种类和用量对短纤维/EPDM复合材料物理性能的影响

研究未处理棉短纤维(SCF)、锦纶短纤维(DN66)和木质纤维素短纤维(E-140)用量对短纤维补强EPDM复合材料(SFRC)物理性能的影响。结果表明,在0~15份用量范围内,随着短纤维用量的增大,SFRC的硬度、100%定伸应力和撕裂强度呈增大趋势,拉伸强度和拉断伸长率呈下降趋势,其中填充DN66的SFRC 100%定伸应力和撕裂强度明显增大,拉伸强度下降较小,填充SCF的SFRC拉断伸长率下降较小。扫描电镜观察发现,未处理SCF在EP-DM基质中团聚严重,与基体的界面粘合性能较差。     

炭黑/再生橡胶复合填料对天然橡胶补强性能的影响

针对传统橡胶基补强填料在补强橡胶基体时容易发生团聚,形成缺陷结构,降低橡胶制品的综合性能问题,研究了炭黑/再生橡胶(CB/RR)和炭黑/胶粉(CB/GTR)复合填料填充天然橡胶(NR)硫化胶的物理机械性能和动态力学性能,分别探讨了不同用量比的CB/RR以及CB/GTR复合填料对NR综合性能的影响。结果表明,当CB/GTR并用时,随着GTR用量增加,并用胶拉伸强度、拉断伸长率、硬度、储能模量和损耗模量均逐渐降低;与CB/GTR并用相比,CB/RR并用填充NR的硫化速率慢,损耗因子低,拉伸强度、拉断伸长率、硬度、储能模量和损耗模量更高。当CB/RR填料并用质量比为30/30时,NR硫化胶的物理机械性能和界面相容性较好,NR硫化胶表面光滑平整,其拉伸强度最大可达22.5MPa,比同比例下CB/GTR填充胶的拉伸强度提高了10.6MPa。     

氧化镁填充导热硅橡胶的性能研究

对氧化镁填充导热硅橡胶的性能进行研究.结果表明,氧化镁用量在200份以下时,小粒径氧化镁填充硅橡胶的热导率和拉伸强度大于大粒径氧化镁填充硅橡胶,而拉断伸长率则相反;大粒径氧化镁/小粒径氧化镁并用比为100/100时硅橡胶的热导率最大;添加适量的硅烷偶联剂有利于提高硅橡胶的热导率,其最佳用量约为大粒径氧化镁用量的0.5%.     

不同粒径球形氧化铝粉体填充硅橡胶热导率研究

采用不同粒径的球形ɑ-Al2O3粉体填充甲基乙烯基硅橡胶,研究了粉体粒径和粉体体积填充率对复合材料热导率的影响;并用理论模型与实验数据进行拟合,揭示出导致复合材料热导率差别的微观机理。研究结果表明:球形氧化铝粉体作为复合材料增强相,其体积填充率越大,复合材料的热导率越高;对于某一固定的体积填充率,随着粉体粒径的增大,复合材料的热导率也增大,而且体积填充率越高,这种差异越明显。     

硫酸钡粉体在PVC-U复合材料中的应用

对硫酸钡粉体应用于PVC—U复合材料进行了初步研究，着重论述了各组分对复合材料的力学性能和相对密度的影响，利用激光粒度测试仪对硫酸钡粉体进行了测试，得到了粒径分布曲线和累计曲线。结果表明，PVC树脂质量对复合材料的力学性能影响很大，对相对密度影响不大：当硫酸钡用量相同时，硫酸钡的活化与否与粒径大小对复合材料的相对密度影响不大；当硫酸钡用量增加时，复合材料拉伸强度降低，相对密度增加；随着DOP用量的增加，复合材料的拉伸强度降低，断裂伸长率显著增大，相对密度下降。     

活化粉煤灰/NR复合材料的制备与性能研究

采用硅烷偶联剂对粉煤灰进行活化处理,制备活化粉煤灰/NR复合材料并对其性能进行研究.结果表明,与未活化粉煤灰/NR复合材料相比,活化粉煤灰/NR复合材料的邵尔A型硬度、拉伸强度和拉断伸长率明显增大;活化粉煤灰用量为20份时,复合材料的拉伸强度和拉断伸长率达到最大值.随着活化粉煤灰用量的增大,活化粉煤灰/NR复合材料的耐热性能明显提高,燃烧速率减慢,阻燃性能逐渐提高.活化粉煤灰作为橡胶填料,可部分替代炭黑降低橡胶制品生产成本,同时有利于环保.     

氧化石墨烯/聚氨酯复合材料的制备及性能研究

采用溶液共混浇注成膜法制备氧化石墨烯/热塑性聚氨酯(TPU)复合材料,并对其结构和性能进行研究。结果表明:氧化石墨烯在TPU基体材料中分散较好;随着氧化石墨烯用量(0～5份)的增大,氧化石墨烯/TPU复合材料的拉伸强度增大,拉断伸长率未明显下降;当相同用量(均为1份)的氧化石墨烯、碳纳米管、石墨和炭黑分别填充TPU时,氧化石墨烯/TPU复合材料物理性能提高幅度最大,补强性能最好。     

不同种类短纤维对天然橡胶/丁苯橡胶复合材料性能的影响

分别以尼龙66短纤维、芳纶短纤维及聚酯短纤维作为增强剂,天然橡胶（NR）和丁苯橡胶（SBR）作为基体制备了短纤维增强NR/SBR（短纤维/NR/SBR）复合材料,采用正交实验方法研究了短纤维种类、长度及用量对短纤维/NR/SBR复合材料的拉伸性能、硬度、撕裂强度的影响。结果表明,经过浸渍处理后的尼龙66短纤维与NR/SBR基体之间的结合最为紧密;浸渍处理后的尼龙66短纤维可以有效提高NR/SBR复合材料的拉伸强度,在一定范围内,随着短纤维长度和用量的增加,短纤维/NR/SBR复合材料的拉伸强度有所提高;短纤维的加入提高了NR/SBR复合材料的撕裂强度和硬度,但扯断伸长率则有所下降。     

Studies on Mechanical,Thermal, and Flame Retarding Properties of Polybutadiene Rubber (PBR) Nanocomposites

An effect of nanosize CaCO₃ on physical, mechanical, thermal and flame retarding properties of PBR was compared with commercial CaCO₃ and fly ash filled PBR. CaCO₃ at the rate of 9, 15, and 21 nm were added in polybutadiene rubber (PBR) at 4, 8 and 12 wt.% separately. Properties such as swelling index, specific gravity, tensile strength, Young's modulus, elongation at break, modulus at 300% elongation, glass transition temperature, decomposition temperature, flame retardency, hardness, and abrasion resistances were determined. The swelling index decreased and specific gravity increased with reduction in particle size of fillers in PBR composites. There was significant improvement in physical, mechanical, thermal and flame-retarding properties of PBR composites due to a reduction in the particle size of fillers. Maximum improvement in mechanical and flame retarding properties was observed at 8 wt.% of filler loading. This increment in properties was more pronounced in 9 nm size CaCO₃. The results were not appreciable above 8 wt.% loading of nano fillers because of agglomeration of nanoparticles. In addition, an attempt was made to consider some thermodynamically aspects of resulting system. The cross-linkage density has been assessed by Flory-Rehner equation in which free energy was increased with increase in filler content.     

Mechanical properties and processibilty of glass‐fiber‐, wollastonite‐, and fluoro‐rubber‐reinforced silicone rubber composites

The reinforcement of silicone rubber (SR) imparted by different types of fillers was investigated. Glass fiber (GF), wollastonite and fluoro rubber (FR) as nontraditional filler for rubber were compounded SR and mechanical properties of the prepared composites were evaluated. The addition of silane pretreated GF and wollastonite into SR, tensile strength, abrasion resistance and tear strength of the composites improved considerably. The improvement in the properties was assigned to an increased interaction between the filler and the polymer matrix. For the SR/FR composites system, the elongation at break was increase with increasing concentrations of FR due to sponge like structure resulting from poor compatibility between the two components. To investigate the production potential of extrusion processing method, prepared composites were extruded in a rod type sample. During the curing stage, GF, wollastonite and FR lead to the formation of void in the matrix resin. When GF and wollastonite were treated with silane, the void formations were reduced significantly. The silane treatment process improves not only mechanical strength but also processibility of SR composites in dry conditions. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Preparation and characterization of γ‐irradiated crosslinked silicone rubber/organoattapulgite composites

Silicone rubber (SR)/organoattapulgite (OAT) composites were prepared with γ‐irradiation crosslinking at a dose range varied from 30 to 300 kGy. Natural fibrillar silicate attapulgite (AT) was modified by silane coupling agent, and the obtained OAT was used as reinforcing fillers in SR. The effect of irradiation doses on the degree of crosslinking of SR/OAT composites was determined by solvent swelling method. It was found that the molecular weight between crosslinks (M_c) reduced with the increase in irradiation doses. Moreover, the addition of OAT to SR matrix promoted an increase in the crosslinking density of the composites because of the presence of the active crosslinking sites of OAT. The mechanical properties of the SR/OAT composites including tensile strength, elongation at break, and Shore A hardness subjected to various irradiation doses were studied. The experimental results showed that the tensile strength, elongation at break, and Shore A hardness were all improved significantly in the presence of OAT, which indicated that OAT was an alternative reinforcing filler of SR. In addition, the effect of various irradiation doses on the mechanical properties of SR and SR/OAT composites was also investigated. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers     

Mechanical Properties of Melt-processed Blend of Amorphous Corn Flour Composite Filler and Styrene-Butadiene Rubber

The corn flour composite fillers were prepared by blending corn flour with rubber latex, dried, and cryogenically ground into powders, which were then melt-blended with rubber polymers in an internal mixer to form composites with enhanced mechanical properties. The composites prepared with melt-blending method were compared to those prepared with a freeze-drying method. The composite fillers prepared with styrene-butadiene were compared to those made with carboxylated styrene-butadiene matrix. Dynamic effects showed that the corn flour composite fillers produced composites with good tensile strength, elongation ratio, and toughness at 500 mm/min strain rate. Tear resistance of different composites was also studied.     

聚磷酸铵/氢氧化镁复配填充阻燃硅橡胶的研究

分别采用聚磷酸铵（APP）、氢氧化铝（ATH）和APP/ATH复配阻燃剂填充甲基乙烯基硅橡胶,制成阻燃型硅橡胶。研究了APP、ATH和APP/ATH用量及复配方式对硅橡胶阻燃性能、介电性能和力学性能的影响。结果表明,硅橡胶的阻燃性能随APP、ATH用量的增加而增加,同等填充量下,APP/ATH复配阻燃剂填充硅橡胶的阻燃性能比单一APP或ATH填充硅橡胶更佳;随着APP/ATH复配阻燃剂用量的增加,硅橡胶的拉伸强度与拉断伸长率降低,邵尔A硬度、介电常数和介质损耗因数增加。当100份硅橡胶中加入80份APP/ATH复配阻燃剂（APP与ATH的质量比为3∶2）时,硅橡胶的氧指数达44%,拉伸强度、拉断伸长率、邵尔A硬度、介电常数及介质损耗因数分别为6.8 MPa、438%、62度、3.92、249%。     

Hybridized reinforcement of natural rubber with silane‐modified short cellulose fibers and silica

Natural‐rubber‐based hybrid composites were prepared by the mixture of short cellulose fibers and silica of different relative contents with a 20‐phr filler loading with a laboratory two‐roll mill. The processability and tensile properties of the hybrid composites were analyzed. The tensile modulus improved, but the tensile strength and elongation at break decreased with increasing cellulose fiber content. The scorch safety improved with the addition of 5‐phr cellulose fiber in the composites. The Mooney viscosity significantly decreased with increasing cellulose fiber content. To modify the surface properties of the cellulose fiber and silica fillers, a silane coupling agent [bis(triethoxysilylpropyl)tetrasulfide, or Si69] was used. The effects of Si69 treatment on the processing and tensile properties of the hybrid composites were assessed. We found that the silane treatment of both fillers had significant benefits on the processability but little benefit on the rubber reinforcement. The strength of the treated hybrid composite was comparable to that of silica‐reinforced natural rubber. Furthermore, to investigate the filler surface modification and to determine the mixing effects, infrared spectroscopic and various microscopic techniques, respectively, were used. From these results, we concluded that the fillers were better dispersed in the composites, and the compatibility of the fillers and natural rubber increased with silane treatment. In conclusion, the hybridized use of short cellulose fibers from a renewable resource and silica with Si69 presented in this article offers practical benefits for the production of rubber‐based composites having greater processability and more environmental compatibility than conventional silica‐filler‐reinforced rubber. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Physico-mechanical and dynamic mechanical studies of nanographite reinforced chlorobutyl nanocomposites

Abstract

Nanographite reinforced chlorobutyl elastomer (CIIR) nanocomposites were prepared. The dispersion of the nanographite in the CIIR matrix has been investigated by scanning electron microscopy. The effect of increasing nanographite loadings (2, 4, 6 and 8 phr) on mechanical properties like tensile strength, hardness, elongation at break and modulus (100, 200 and 300%) has been studied. The study shows increase in tensile strength, hardness and modulus and decrease in elongation at break with nanographite loading, which can be attributed towards better CIIR–nanographite interaction. The above explanation was again verified from bound rubber measurements. It shows increase in bound rubber contents with nanographite loading. Dynamic mechanical analysis was used to study their relaxation behaviour as a function of temperature (?100 to 100°C) at frequency 1 Hz and 1% strain. The effect of increasing nanographite loadings on glass transition temperature was marginal in all the composites, and Tg value was in the range of ?10 to 10°C, which has been explained on the basis of relaxation dynamics of polymer chains in the vicinity of fillers. The effects of variation in nanographite loading and temperature on dynamic mechanical properties like loss tangent, storage and loss modulus have been reported. The effect of solvent (chloroform, benzene and tri-chloroethylene) on swelling properties at different periods of time (15, 30, 45 and 60 min) shows that the degree of swelling increases with time and decreases with concentration of nanographite loading.     

Thermoplastic Elastomer Composites of Palm Ash-Filled Ethylene Vinyl Acetate/Natural Rubber Blends: Effects of Palm Ash Loading and Size

Thermoplastic elastomer composites of ethylene vinyl acetate (EVA)/natural rubber (NR) blends filled with palm ash were prepared by melt-mixing using a Haake Rheomix Polydrive R600/610 at 120°C with rotor speed of 50 rpm for 10 minutes. Increase in palm ash loading in composites resulted in increase the value of stabilization toque, Young's modulus and swelling resistance of the composites, but decreased the tensile strength and elongation at break. Scanning electron microscope micrographs revealed that higher filler loading resulted in agglomeration of palm ash in the composites. When smaller particle size of palm ash was used, further improvement in tensile strength, elongation at break, swelling resistance and stabilization torque value were observed.     

A study on effect of mineral additions on the mechanical,thermal, and structural properties of poly(butylene terephthalate) (PBT) composites

Fillers play a major role in determining the properties and behavior of polymer composites. In this study a series of polybutylene terephthalate composites are fabricated using mica and talc particles as filler materials. The effects of these two different minerals on the mechanical, thermal and structural properties of composites are investigated. Comparative analysis shows that both the fillers have different effect on tensile strength and elongation at break. The experimental results when compared with theoretical predictions reveal high level of interfacial interaction in both the composite systems. The interaction parameter B derived using Pukanszky equation is found to be higher in mica filled composites which is in agreement with its better mechanical response. Microscopic observation by SEM reveals that both fillers exhibit different fracture micromechanics leading to different reinforcing effects in PBT.