改性锦纶66短纤维/天然橡胶复合材料性能研究

对锦纶66（PA66）短纤维进行紫外光照射和浸渍液体橡胶物理改性,以及接枝化学改性共同处理,制备改性PA66短纤维/天然橡胶（NR）复合材料,并研究PA66短纤维改性方式对复合材料性能的影响。结果表明：与未改性的PA66短纤维/NR复合材料相比,改性PA66短纤维/NR复合材料的拉伸强度降低、撕裂强度提高;其中先接枝再紫外光照的PA66短纤维/NR复合材料的100%定伸应力变化不大,300%定伸应力提高,拉断伸长率变化不大;先紫外光照再接枝的PA66短纤维/NR复合材料的100%定伸应力和300%定伸应力明显提高,拉断伸长率明显降低。综合来看,经紫外光照4 min＋接枝乙烯基三甲氧基硅烷＋浸渍2 g液体橡胶处理的改性PA66短纤维/NR胶料的物理性能、粘合性能和尺寸稳定性最好。     

短切碳纤维增强天然橡胶/丁苯橡胶复合材料性能研究

用聚丙烯腈短切碳纤维(Carbon fiber,简称CF)作为增强剂,天然橡胶(NR)与丁苯橡胶(SBR)作为基相制备了CF/NR/SBR橡胶复合材料,研究了短切碳纤维用量对CF/NR/SBR复合材料的硫化特性、拉伸强度、邵尔硬度、撕裂强度、阿克隆磨耗及导热系数等性能的影响。研究结果表明,随着CF用量的增加,复合材料拉伸强度逐渐减小,最大损失量达到16%,复合材料的硬度逐渐增大,最大增加量达到36%;复合材料的撕裂强度先增加后降低,在碳纤维用量为5份时达到最大值,最大增加量达到37%;复合材料的导热性能逐渐提高,最大增加量达到43%。     

纳米氧化锌在槟榔纤维素短纤维/天然橡胶复合材料中的应用

研究纳米氧化锌在槟榔纤维素短纤维（BCF）/天然橡胶（NR）复合材料中的应用。结果表明：与普通氧化锌相比,纳米氧化锌在BCF/NR复合材料中分散均匀,无明显团聚现象;随着纳米氧化锌用量增大,BCF/NR复合材料的硫化速率和交联密度提高,耐溶胀性能、拉伸性能和撕裂强度先提升后降低;纳米氧化锌用量为4份时,BCF/NR复合材料的拉伸性能、撕裂强度、耐溶胀性能和耐老化性能最好。     

长玻璃纤维增强尼龙66力学性能的研究

采用自行研制的熔体浸渍包覆长玻纤装置,制备了长玻纤增强尼龙66(LFT-PA66)复合材料.研究了玻纤用量、预浸料粒料长度和相容剂聚丙烯接枝马来酸酐(PP-G-MAH)对长纤维增强尼龙66的拉伸强度和冲击强度的影响.结果表明:长玻纤增强尼龙66的力学性能明显优于短玻纤增强尼龙66(SFT-PA66),相容剂PP-G-MAH的加入增强了界面黏结强度,提高了长玻纤增强尼龙66复合材料的拉伸强度和冲击强度.     

两种橡胶/有机累托石纳米复合材料的结构与性能

比较了用熔体法制备的有机累托石(OR)/丁苯橡胶(SBR)以及有机累托石(OR)/天然橡胶(NR)2种纳米复合材料的结构与性能.TEM和XRD对材料的分析显示,由于橡胶基体的性质差异,OR/SBR为典型的插层型结构,而OR/NR为插层型和部分剥离型混合结构.应力应变行为的研究表明,随着OR用量的增加,OR/SBR的拉伸强度和拉断伸长率均增大,这主要是分子链滑移和填料的取向造成的.对于拉伸结晶型橡胶NR,由于部分剥离型填料的增强作用,NR的定伸应力随填料用量的增加而逐渐提高.由于对结晶的阻碍作用,当OR用量为20份时,OR/NR的拉伸强度有所降低.纳米累托石的加入可以显著提高SBR和NR的硬度和撕裂强度.热失重分析表明,OR/橡胶纳米复合材料与相应的纯橡胶相比,热稳定性提高,在NR体系中更为显著.     

尼龙和聚酯短纤维的长度对其与天然橡胶氯丁橡胶复合材料性能的影响

本就尼龙，聚酯短纤维的长度对尼龙－天然橡胶以及聚酯－氯丁橡胶复合材料的物理性能和溶胀性能的影响进行了理论研究。实验结果表明：这两种短纤维橡胶复合材料的撕裂强度，２０％定伸应力随短纤维长度增加而增大，抗溶胀能力增强，拉伸强度则在短纤维最佳长径比条件下最好。尼龙，聚酯短纤维经Ｄ法预处理后，其复合材料的各基性能均有较大提高。     

抗裂口树脂AD-1600对NR/SBR并用胶性能的影响

研究了补强树脂种类及抗裂口树脂AD-1600用量对天然橡胶/丁苯橡胶（NR/SBR）并用胶性能的影响。结果表明,抗裂口树脂AD-1600、补强树脂OD-60均可提高NR/SBR硫化胶的拉伸强度、撕裂强度及耐磨耗性等性能;随AD-1600用量增加,拉伸强度和撕裂强度先增大后减小,DIN磨耗体积先减小后增大,呈单峰型变化规律,但各项性能达到最佳值时AD-1600用量不一致。     

有机硅乳液用量对天然橡胶/丁苯橡胶并用胶性能的影响

研究有机硅乳液用量对天然橡胶（NR）/丁苯橡胶（SBR）并用胶性能的影响。结果表明：随着有机硅乳液用量的增大,NR/SBR并用胶的门尼粘度和FL减小,表明有机硅乳液可改善并用胶的加工性能;NR/SBR并用胶的t10和t90缩短,表明有机硅乳液会降低并用胶的加工安全性,但可提高并用胶的硫化速率;NR/SBR并用胶的拉伸强度、拉断伸长率和撕裂强度和DIN磨耗量先增大后减小,Payne效应先增强后减弱。当有机硅乳液用量为6.8份时,NR/SBR并用胶的物理性能、耐磨性能和炭黑分散性最好。     

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。     

锦纶短纤维/天然橡胶复合材料的性能研究

制备锦纶66短纤维/天然橡胶(NR)复合材料,并研究锦纶短纤维用量对复合材料性能的影响。结果表明:锦纶短纤维可以提高胶料的定伸应力和撕裂强度,当锦纶短纤维用量为4份时,锦纶短纤维/NR复合材料的综合物理性能最好;添加锦纶短纤维增大了填料有效体积,提高了对橡胶分子链的束缚,使橡胶分子在剪切作用力下运动受阻,提高了抵抗外力变形的能力;锦纶短纤维降低了NR胶料的玻璃化转变温度,有利于NR胶料在低温下使用。     

Tear and processing behaviour of short sisal fibre reinforced styrene butadiene rubber composites

The tear failure and processing characteristics of short sisal fibre reinforced styrene butadiene rubber (SBR) composites were investigated. Tear strength was examined with special reference to the effects of fibre length, fibre orientation, fibre concentration and bonding agent. It was observed that the tear strength depends on all the above factors. The tear failure mechanism was analysed from fractographs taken using a scanning electron microscope (SEM). During tear testing, the composites failed by a shearing process. Microscopic examination of cracks propagating in SBR composites revealed that the amorphous SBR matrix developed cracks, leaving ligaments of rubber attached to the broken fibres. The rubber particles were stretched as the crack opened and failure occurred at large critical extensions. It was observed that an increase in the concentration of fibres increased the tear strength in both longitudinal and transverse directions. The tear strength values were almost three to four times higher than those of the unfilled vulcanizates under similar conditions. In order to analyse the processing behaviour, the green strength, mill shrinkage and Mooney viscosity of the compounds were determined. Finally, the polymer–filler interaction was studied using the Lorenz–Park and Kraus equations.     

熔体法制备有机黏土/橡胶纳米复合材料的结构及性能

将有机黏土(OC)分别加入到天然橡胶(NR)、丁苯橡胶(SBR)、丁基橡胶(IIR)和三元乙丙橡胶(EPDM)中,通过熔体法制备了纳米复合材料。探讨了橡胶黏度及其分子结构对OC在复合材料中分散状况的影响,研究了复合材料的力学性能。结果表明,在以NR为基体的复合材料中。OC片层分散均匀,且剥离程度较高;在SBR,IIR,EPDM中,OC以插层结构为主,且插层效果从大到小的顺序依次为SBR,IIR,EPDM。与相应的纯胶相比,OC／NR纳米复合材料的定伸应力提高,拉伸强度和扯断伸长率有所下降;OC／SBR,OC／IIR,OC／EPDM纳米复合材料的定伸应力变化不大,拉伸强度和扯断伸长率明显提高,且OC／SBR和OC／EPDM复合材料的撕裂强度提高。     

Oil Palm Fibre-reinforced Rubber Composite: Effects of Concentration and Modification of Fibre Surface

The effects of concentration and modification of fibre surface in oil palm fibre-reinforced rubber composites have been studied. Modification of the fibre surface increased the physical properties of the rubber composites. Increasing concentration of oil palm fibre in the rubber matrix resulted in reduction of tensile strength properties and tear strength, but increased modulus and hardness of the composites. Scanning electron micrograph studies showed that for rubber composites filled with untreated fibre, the adhesion between the fibre and matrix is poor, while for treated fibre improved adhesion between the fibre and rubber matrix is evident. © 1997 SCI.     

Effect of Impact Modifier Types on Mechanical Properties of Rubber‐Toughened Glass‐Fibre‐Reinforced­ Nylon 66

The effect of adding rubber on the properties of glass‐fibre‐filled nylon 66 was investigated in this study. Styrene‐Ethylene‐Butylene‐Styrene and Ethylene‐Propylene elastomers grafted with maleic anhydride (SEBS‐g‐MA and EP‐g‐MA, respectively) were used to toughen the nylon‐matrix composites. Impact strength and elongation at break were found to increase with increasing rubber content, but flexural strength, tensile strength and stiffness decreased; however, by adding moderate amounts of rubber to glass‐fibre‐reinforced nylon 66, a desirable balance between stiffness and toughness of the material may be obtained. For example, the addition of 10 wt.% of SEBS‐g‐MA to nylon 66 with 23.62 wt.% glass fibre loading resulted in 28.3% and 167% increase in tensile strength and impact strength of the composites, respectively, when compared to neat nylon 66. This suggests that combining both glass fibres and rubber with nylon 66 is a useful strategy to optimize and enhance the properties of nylon 66. The procedure may be used to recycle polyamides, in general, and to develop components for under‐the‐hood automotive applications, in particular.     

Chemically modified starch reinforced natural rubber composites

Chemically modified starch paste (MST) with polybutylacrylate (PBA) graft chains is investigated as a reinforcing filler of rubber through mixing and co-coagulating with natural rubber (NR) latex. The PBA graft chains are designed to prevent hydrogen bonding and crystallization of starch and to improve compatibility between starch and rubber. Through the comparison of mechanical properties and phase morphology, MST is proved to be much superior to unmodified starch paste. Unmodified starch paste acts as essentially inert filler causing a decrease of tensile strength, tear strength and elongation at break. In contrast, optimum MST shows obvious reinforcement effect on NR matrix by increasing tensile strength, elongation at break and tear strength besides modulus and hardness. Moreover, fine starch dispersion and strong interfacial interaction are achieved in NR/MST composites. The observed reinforcement effect is interpreted based on the results of X-ray diffraction (XRD), differential scanning calorimetry (DSC) and scanning electron microscope (SEM) analyses of grafted starch in comparison with natural starch and gelatinized starch.     

白炭黑部分替代莫来石填充丁苯橡胶的性能研究

研究了白炭黑部分替代莫来石填充丁苯橡胶（SBR）对胶料的硫化特性和硫化胶力学性能的影响。结果表明：白炭黑可以减缓莫来石对SBR的促进硫化作用;白炭黑的少量加入可以促使莫来石粉体在SBR基体中的均匀分散,表现为硫化胶除了拉伸永久变形外,拉伸性能、撕裂性能和硬度增加,具有良好的协同效果。     

Mechanical properties of surface‐modified ultra‐high molecular weight polyethylene fiber reinforced natural rubber composites

The mechanical properties of ultra‐high molecular weight polyethylene (UHMWPE) fibers reinforced natural rubber (NR) composites were determined, and the effects of fiber surface treatment and fiber mass fraction on the mechanical properties of the composites were investigated. Chromic acid was used to modify the UHMWPE fibers, and the results showed that the surface roughness and the oxygen‐containing groups on the surface of the fibers could be effectively increased. The NR matrix composites were prepared with as‐received and chromic acid treated UHMWPE fibers added 0–6 wt%. The treated UHMWPE fibers increased the elongation at break, tear strength, and hardness of the NR composites, especially the tensile stress at a given elongation, but reduced the tensile strength. The elongation at break increased markedly with increasing fiber mass fraction, attained maximum values at 3.0 wt%, and then decreased. The tear strength and hardness exhibited continuous increase with increasing the fiber content. Several microfibrillations between the fiber and NR matrix were observed from SEM images of the fractured surfaces of the treated UHMWPE fibers/NR composites, which meant that the interfacial adhesion strength was improved. POLYM. COMPOS., 38:1215–1220, 2017. © 2015 Society of Plastics Engineers     

淀粉/天然橡胶复合材料的研究

将淀粉进行糊化改性,将改性淀粉在乳液状态下与天然胶乳共混,制备淀粉/天然橡胶复合材料。用X-射线衍射（XRD）、差示扫描量热仪（DSC）和扫描电镜（SEM）表征复合材料的结构,并测定了其力学性能。研究结果表明：淀粉经糊化后,复合材料中淀粉粒子的结晶结构消失,粒子在天然橡胶中分散均匀,粒径明显减小。随着淀粉含量的增加,复合材料的硬度、定伸应力、拉伸强度和撕裂强度随之提高,且当其质量分数在20%时,复合材料的综合力学性能最佳。