模压成型ABS微孔发泡材料的研究

采用化学交联模压法制备了丙烯腈-苯乙烯-丁二烯共聚物(ABS)微孔发泡材料,研究了发泡温度、发泡压力、发泡时间等加工参数对泡孔性能的影响,采用力学测试方法、扫描电子显微镜(SEM)研究了ABS微孔发泡材料的力学性能和泡孔形态。研究结果表明,当发泡温度为170℃、发泡压力为10 MPa、发泡时间为12 min时,制得的ABS微孔发泡材料泡孔尺寸、泡孔密度适中,表观密度最小,同时具有较好的冲击强度。在此模压工艺参数下,材料的平均泡孔直径约为50μm,泡孔密度约为3.2×108个/cm3,满足工业上微孔发泡材料泡孔密度的要求。     

注射温度对ABS复合材料发泡行为及力学性能的影响

利用型腔体积可控注塑发泡装备制备丙烯腈-丁二烯-苯乙烯(ABS)发泡材料,分析了不同注射温度下发泡ABS复合材料的发泡行为,并对其力学性能进行研究。结果表明:随着注射温度的升高,泡孔结构先变好,后趋于恶化。当注射温度为175℃时,ABS发泡材料的发泡质量较理想,其泡孔平均尺寸和泡孔密度分别为20.3μm、2.2×106个/cm3。就力学性能而言,注射温度为175℃时,拉伸强度发生小范围下降,而冲击强度增加到14.2 k J/m2,综合力学性能较为理想。     

摩托车金属连接件ABS轻量化设计与FDM增材制造

针对摩托车金属连接件轻量化需求,对金属连接件进行了两次轻量化优化设计,第一次是在满足连接件使用性能的条件下更改连接件材料,由铝合金更改为丙烯腈-丁二烯-苯乙烯塑料(ABS)塑料,此次更改,实现60%的减重;第二次也是在满足连接件使用性能的基础上采用Altair Inspire软件对其进行拓补优化、几何重构及强度校核,得到适合于3D打印的结构,相对第一次优化后的结构实现79%的减重效果,通过两次轻量化优化设计后连接件相对于原始金属连接件实现了92%的减重,然后通过切片软件设置切片层厚、连接件摆放位置等参数对连接件三维数据进行前处理,最后通过3D打印机实现摩托车连接件FDM快速制造,为摩托车金属零件轻量化设计与制造提供了一种新的思路。     

SBS在低光泽ABS材料中的应用研究

通过3种不同弹性体对丙烯腈-丁二烯-苯乙烯共聚物(ABS)材料的消光效果进行了比较,筛选出了合适的弹性体消光剂,考察其用量对ABS材料光泽度和性能的影响,并与无机粉体消光剂作了比较。结果表明,相比弹性体POE-g-MAH和乙烯-甲基丙烯酸甲酯共聚物接枝甲基丙烯酸缩水甘油酯,苯乙烯-丁二烯-苯乙烯共聚物(SBS)不仅能显著降低ABS材料的光泽度,而且表面无分层,效果较好;随着SBS用量的增加,ABS材料的光泽度逐渐降低,当SBS用量超过10%(质量分数,下同)后,材料的光泽度下降趋于平缓;加入SBS可改善材料的加工性能,但材料的力学性能,特别是冲击强度下降较快,添加一定量的本体法ABS可明显提高材料的冲击强度;与无机粉体消光剂比较而言,相同光泽度情况下冲击性能保持得较好,性价比高。     

新能源汽车轻量化的关键技术

汽车轻量化是目前汽车节能减排最有效途径之一。以新能源汽车轻量化为目标,对新能源汽车轻量化进行关键技术的探索和研究。研究表明:通过采用纤维增强热塑性材料的全塑车身、纤维增强集成地板以及铝制轻量化车身框架等技术,可以有效减轻新能源汽车的整车质量,使整车质量降至850 kg(包括电池),可改善新能源汽车的驾驶性能和行驶里程,并通过模块化旋塑模具实现全塑车身成型制造。     

ABS/PCM-PET合金的性能研究

采用共混的方法制备了丙烯腈-丁二烯-苯乙烯(ABS)/回收聚对苯二甲酸乙二醇酯(PCM-PET)合金材料。分别研究了ABS树脂、共聚酯、扩链剂、增韧剂等对合金材料性能的影响。结果表明:用高冲击ABS替代中冲击ABS或加入共聚酯后合金的韧性提高明显;扩链剂可增加材料的强度,断裂伸长率的增加较明显,但材料的熔体质量流动速率明显降低;采用苯乙烯接枝改性剂(S-g-M),将其加入ABS/PCM-PET合金中可使韧性显著改善,材料的缺口冲击强度从14.8 kJ/m2提升至19.5 kJ/m2。     

橡胶含量对ABS树脂性能的影响

采用聚丁二烯接枝苯乙烯-丙烯腈共聚物(PB-g-SAN)与苯乙烯-丙烯腈共聚物(SAN)熔融共混,制备了一系列丙烯腈-丁二烯-苯乙烯共聚树脂(ABS),考察了橡胶含量对该ABS树脂物理力学性能的影响。结果表明:随着橡胶含量的增加,ABS树脂的拉伸强度、弯曲强度、弯曲模量、熔体流动速率、热变形温度、密度和硬度均有所降低,而缺口冲击强度和断裂伸长率提高。因此可通过调节橡胶含量来制备具有不同物理力学性能的ABS树脂,以满足不同的应用需要。     

PC/改性ABS复合材料的制备与性能

在传统的丙烯腈-丁二烯-苯乙烯共聚物(ABS)乳液接枝聚合中加入甲基丙烯酸甲酯(MMA),制得了改性ABS,然后与聚碳酸酯(PC)共混挤出，制得了PC/改性ABS复合材料。研究了MMA用量对PC/改性ABS复合材料的熔体流动速率(MFR)、维卡软化温度、力学性能的影响。结果表明：随着MMA用量的增加，PC/改性ABS复合材料的MFR、拉伸强度、弯曲强度和缺口冲击强度均先升高后降低。当MMA质量分数为20%时，PC/改性ABS复合材料的拉伸强度和弯曲强度均达到最大，分别为48.9 MPa和63.2 MPa;当MMA质量分数为30%时，PC/改性ABS复合材料的缺口冲击强度为41.0 kJ/m²;当MMA质量分数不高于30%时，与PC/ABS复合材料相比，PC/改性ABS复合材料的维卡软化温度更高。     

ABS/Nano-ZnO/CCA复合材料的制备及抗菌性能研究

以丙烯腈-丁二烯-苯乙烯共聚物(ABS)为基体树脂、纳米氧化锌(Nano-ZnO)为抗菌剂、叶绿素铜酸(CCA)为光敏化剂,采用熔融共混法制备了ABS/Nano-ZnO/CCA复合抗菌材料,并研究了该复合材料的抗菌性能和力学性能。结果表明:ABS/Nano-ZnO复合材料具有良好的抗菌性,添加CCA后,复合材料的抗菌性能进一步提升,其抗菌率接近100%,达到强抗菌材料的要求。Nano-ZnO和CCA的加入对基体材料的拉伸强度、弯曲强度影响不大,材料的冲击强度则有所下降。     

ABS及PS-g-GMA对回收PET的改性研究

以回收聚对苯二甲酸乙二醇(酯rPET)为基体材料,丙烯腈-丁二烯-苯乙烯共聚(物ABS)为增强材料,甲基丙烯酸缩水甘油酯接枝聚苯乙烯(PS-g-GMA)为增容剂,制备了rPET/ABS共混物。采用SEM、DSC等方法对共混物的形态结构、结晶性能和力学性能进行了表征。结果表明:与纯rPET相比,ABS增韧后的rPET缺口冲击强度和断裂伸长率分别提高了54.0%和47.2%,弯曲强度和拉伸强度略有下降,熔融温度下降了1.27℃,结晶温度升高了31.22℃,结晶速度明显加快;PS-g-GMA的加入改善了rPET/ABS共混物的两相界面结合力,细化了两相结构;与纯rPET相比,含1%PS-g-GMA的rPET/PS-g-GMA/ABS共混物的缺口冲击强度提高了72.5%断,裂伸长率提高了71.7%。     

免烧轻集料的研究现状和发展综述

免烧轻集料或冷粘轻集料,能够大量回收利用工业废弃物,且无需烧结,具有良好的经济效益、环境效益和社会效益。本文归纳了免烧轻集料的制备技术和产品达到的性能,综述了免烧轻集料的养护方式及其在混凝土和其他领域中的应用。免烧轻集料产品具有密度偏高、吸水率偏大、比强偏低等问题,本文归纳了降低密度的措施和壳层强化技术,如引气、使用轻质材料和采用核壳结构,提出核壳结构是免烧轻集料轻质高比强和功能化的发展方向,并论述了实现免烧轻集料轻质高比强和功能化中亟待解决的问题。     

The effects of air content on permeability of lightweight concrete

Air entraining agent is used to control the floatation of lightweight aggregate (LWA) in lightweight aggregate concrete (LWAC), therefore reducing the segregation of LWAC. At the same time, using an air entraining agent will affect the water sorption of the concrete. In this paper, two lightweight concrete mixes of density 1000 kg/m³ and air content of 13.5% and 31.9% were compared and the effects of entrained air on the strength, surface sorptivity, and chloride permeability of LWAC are presented. Results show that the use of porous LWA would not lower the permeability resistance of concrete. Entrained air had little effect on sorptivity but a major effect on chloride permeability. The weaker pores' network in the cement paste is the basic cause for the high chloride permeability of concrete than the use of porous LWA. Although chloride permeability of low density LWAC concrete decreased with age of concrete, it was found that the concrete was not dense enough to stop the chloride ion to penetrate through the concrete before the concrete mature at 90 days.     

Impact behavior and fracture morphology of acrylonitrile–butadiene–styrene resins toughened by linear random styrene–isoprene–butadiene rubber

A novel toughening modifier, styrene–isoprene–butadiene rubber (SIBR), was used to improve the impact resistance and toughness of acrylonitrile–butadiene–styrene (ABS) resin via bulk polymerization. For comparison, two kinds of ABS samples were prepared: ABS‐1 was toughened by a conventional modifier (a low‐cis polybutadiene rubber/styrene–butadiene block copolymer), and ABS‐2 was toughened by SIBR. The mechanical properties, microstructures of the as‐prepared materials, and fracture surface morphology of the specimens after impact were studied by instrumented notched Izod impact tests and tensile tests, transmission electron microscopy, and scanning electron microscopy, respectively. The mechanical test results show that ABS‐2 had a much higher impact strength and elongation at break than ABS‐1. The microscopic results suggested that fracture resistance of ABS‐1 only depended on voids, shear yielding, and few crazing, which resulted in less ductile fracture behavior. Compared with ABS‐1, ABS toughened by linear random SIBR (ABS‐2) displayed the synergistic toughening effect of crazing and shear yielding, which could absorb and dissipate massive energy, and presented high ductile fracture behavior. These results were also confirmed by instrumented impact tests. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Non‐traditional lightweight polypropylene composites reinforced with milkweed floss

Lightweight composites are preferred for automotive applications due to the weight restrictions and also due to the presence of inherent voids that can enhance the sound absorption of these composites. The density of the reinforcing materials plays a crucial role in such lightweight composites. Milkweed is a unique natural cellulose fiber that has a completely hollow center and low density (0.9 g cm^?3) unlike any other natural cellulose fiber. The low density of milkweed fibers will allow the incorporation of higher amounts of fiber per unit weight of a composite, which is expected to lead to lightweight composites with better properties. Polypropylene (PP) composites reinforced with milkweed fibers have much better flexural and tensile properties than similar PP composites reinforced with kenaf fibers. Milkweed fiber‐reinforced composites have much higher strength but are stiffer than kenaf fiber‐reinforced PP composites. Increasing the proportion of milkweed in the composites from 35 to 50% increases the flexural strength but decreases the tensile strength. The low density of milkweed fibers allows the incorporation of higher amounts of fibers per unit weight of the composites and hence provides better properties compared to composites reinforced with common cellulose fibers with relatively high density. This research shows that low‐density reinforcing materials can more efficiently reinforce lightweight composites. Copyright © 2010 Society of Chemical Industry     

Chamotte-kaolin insulating bricks with an apparent density of 0.8–0.9 g/c m3

Conclusions Using sandy kaolin raw materials at the Velikoanadaol'sk refractories combine we made lightweight insulants with an apparent density of 0.8 and 0.9 g/cm³, using coke fractions <3 and 5 mm, respectively. In both cases the articles had a relatively high strength and low thermal conductivity.Translated from Ogneupory, No. 1, pp. 15–17, January, 1982.     

Polymere hochleistungs-faserverbundwerkstoffe

Advanced polymer-matrix composites are defined as materials consisting of continuous high strength, high modulus fibers, aligned and embedded in a polymeric matrix. Due to their low density they exhibit specific mechanical properties (i.e., strength/density and stiffness/density) that considerably exceed those of high strength metals, which demonstrates their great potential for lightweight structural components. The primary reinforcement materials are various types of carbon fibers, aramid fibers and glass fibers. While these are commonly combined with epoxy resins, many new matrix systems with distinct property profiles, including heat resistant thermoplastics, have been developed recently. This paper presents an overview of this rapidly developing field covering principles of composite-property improvement, synthesis and processing of the constituent materials, and processing and manufacturing techniques to combine fibers and matrix to produce a composite laminate or part. Several mechanical composite properties critical for structural design and performance are discussed in terms of the contribution of and interaction between the fiber and matrix constituent.     

聚环氧酯的合成及其对PC/ABS相容性的影响

以双酚A环氧树脂和己二酸合成了聚己二酸环氧酯,将环氧酯作为相容剂加入到PC/ABS中通过双螺杆挤出机并注射成型制备了合金,与马来酸酐接枝聚苯乙烯（SMA）相容剂增容的合金的力学性能及分散形态进行了对比。结果表明,聚环氧酯对PC相具有良好的相容性,而SMA对ABS相的相容性较好,二者复合使用可以显著改善合金的相容性;聚环氧酯能明显提高PC/ABS合金的拉伸强度和缺口冲击强度,但过量加入会降低合金的冲击强度;SEM结果表明少量的聚环氧酯即可以使ABS分散相分布均匀,与SMA并用可以使分散相尺寸减小,提高相容性。     

Melt strength of polypropylene: Its relevance to thermoforming

The melt strength of homopolymer, copolymer and high melt strength (HMS) grades of polypropylene (PP) was measured to assess the sagging resistance of PP for thermoforming applications. Acrylonitrile-butadiene-styrene (ABS), which can be easily processed during thermoforming, was also studied in this work. A polymer with high melt strength is considered to have a better sagging resistance. The melt strength measurements were carried out using a Gottfert “Rheotens” melt strength tester. The melt strength of the polymers increased with decreasing temperature and increasing extrusion rate. ABS generally had the highest melt strength in the low extrusion temperature region approaching the thermoforming region, indicating that it has a good sagging resistance during thermoforming. The HMS PP had significantly higher melt strength than conventional PP grades; therefore HMS PP is expected to have an improved sagging resistance. For conventional PP, melt strength was higher for the lower melt flow index (MFI) grades. A sharp increase in the melt strength was observed for conventional PP at low extrusion temperature, probably due to flow-induced crystallization of the PP. These results indicate that to minimise the sagging problem with conventional PP, low MFI grades should be used and thermoforming should be performed at temperatures close to the melting point of PP.     

Epoxy/acrylonitrile-butadiene-styrene copolymer/clay ternary nanocomposite as impact toughened epoxy

Epoxy resins have low impact strength and poor resistance to crack propagation, which limit their many end use applications. The main objective of this work is to incorporate both acrylonitrile-butadiene-styrene copolymer (ABS) and organically modified clay (Cloisite 30B) into epoxy matrix with the aim of obtaining improved material with the impact strength higher than neat epoxy, epoxy/clay and epoxy/ABS hybrids without compromising the other desired mechanical properties such as tensile strength and modulus. Impact and tensile properties of binary and ternary systems were investigated. Tensile strength, elongation at break and impact strength were increased significantly with incorporation of only 4 phr ABS to epoxy matrix. For epoxy/clay nanocomposite with 2.5% clay content, tensile modulus and strength, and impact strength were improved compared to neat epoxy. With incorporation of 2.5% clay and 4 phr ABS into epoxy matrix, 133% increase was observed for impact strength. Ternary nanocomposite had impact and tensile strengths greater than values of the binary systems. Morphological properties of epoxy/ABS, epoxy/clay and epoxy/ABS/clay ternary nanocomposite were studied using atomic force microscopy (AFM) phase imaging, scanning electron microscopy (SEM) and wide angle X-ray diffraction (WAXD). New morphologies were achieved for epoxy/ABS and epoxy/ABS/clay hybrid materials. Exfoliated clay structure was obtained for epoxy/clay and epoxy/ABS/clay nanocomposite.     

氧化铝纤维发展现状及应用前景

氧化铝纤维是高性能的新型无机陶瓷纤维,与碳纤维、碳化硅纤维等非氧化物纤维相比,不仅具有高强度、高模量、耐高温等优良性能,还有很好的高温抗氧化性、耐腐蚀性和电绝缘性,且表面活性好,易与树脂、金属、陶瓷基体复合,形成诸多性能优异的复合材料。在工业高温炉窑、航空航天、交通运输及高新科技领域中,氧化铝纤维都有广泛的应用。笔者介绍氧化铝纤维的制取工艺、生产现状、技术进展及应用前景,并对国内今后氧化铝纤维的发展提出了一些建议。