不饱和聚酯型人造大理石的力学性能

简述了不饱和聚酯(UPR)型人造大理石的制备工艺。研究了质量比为4∶1的Al(OH)3/Ca(OH)2复合填料用量对不饱和聚酯型人造大理石力学性能的影响,对制得的人造大理石的耐腐蚀性进行了测试,采用光学显微镜观察了试样腐蚀前后的表面形貌。结果表明,在复合填料与UPR质量比为1.86∶1时,弯曲强度、压缩强度达到最大,分别为55.88 MPa和96.04 MPa。甲苯对人造石的腐蚀作用最大,氢氧化钠次之,硫酸腐蚀作用较小,腐蚀介质主要对不饱和树脂聚合物产生腐蚀,从而导致人造石力学性能降低。     

新型低收缩性无机填料

<正> 众所周知,低收缩性添加剂和无机填料是不饱和聚酯模塑料SMC、BMC的主要组分,它们对模压制品的质量,尤其是表面外观质量起着举足轻重的作用。热塑性聚合物(聚乙烯粉末或其它热塑性聚合物的苯乙烯溶液)由于热膨胀系数高,在不饱和聚酯交联固化放热过程中产生热膨胀能够部分或全部抵消树脂固化引起的收缩,是常用的低收缩添加剂。无机填料能替代部分树脂,减少树脂的固化收缩,具有控制收缩,改善制品表面质量的作用。最普遍使用的无机填料是碳酸钙。     

漂珠／不饱和聚酯复合材料的耐化学腐蚀性

讨论了漂珠/不饱和聚酯复合材料的耐化学腐蚀性及硅偶联剂处理对复合体系性能影响。浸泡介质选用了沸水、20%盐酸、4.5%和45%氢氧化钠水溶液、饱和食盐水、丙酮、甲苯。测定了浸泡前后拉伸强度和质量变化以及复合材料断面的SEM形貌。结果表明:漂珠/不饱和聚酯体系耐饱和盐水浸蚀性良好,而耐其它几种介质腐蚀不太理想。用偶联剂处理后的复合材料耐沸水、饱和盐水、盐酸腐蚀性有较大改进,而对其它介质则不显著。     

玻纤增强乙烯基酯树脂复合材料在硫酸水溶液中的腐蚀速率研究

用质量变化曲线拟合求导的方法研究不同温度下玻璃纤维增强乙烯基酯树脂(GF/VE)复合材料在40wt%硫酸介质中的腐蚀速率,探讨了介质温度及浸泡时间对腐蚀速率的影响,并对比75℃下乙烯基酯树脂浇注体及玻璃纤维的腐蚀速率,分析了GF/VE复合材料在硫酸中的腐蚀机理.结果表明,乙烯基酯树脂浇注体在硫酸中的腐蚀速率随腐蚀时间的延长逐渐降低,最后基本趋于平衡,玻璃纤维在硫酸中的腐蚀速率随腐蚀时间逐渐增加,但数值很小,而GF/VE复合材料的腐蚀速率随腐蚀时间的延长不断增加,且随温度升高,腐蚀速率增大.结合SEM照片观察得出.GF/VE复合材料在硫酸介质浸泡初始主要是树脂发生腐蚀,后期主要是界面腐蚀起主导作用.     

PVA对碳酸钙、淤泥/不饱和聚酯树脂体系增强的探讨

采用聚乙烯醇(PVA)对碳酸钙、淤泥进行改性并将其作为不饱和聚酯树脂填料。研究了PVA掺量对碳酸钙/不饱和聚酯树脂和淤泥/不饱和聚酯树脂体系力学性能的影响。采用IR、DSC和SEM探讨了PVA对这2类体系的改性机理。实验结果表明:加入5%PVA后,碳酸钙/树脂体系,淤泥/树脂体系弯曲强度分别提高了55.3%和58.4%。PVA对2种体系的改性增强效应均源于PVA与填料和树脂之间氢键的桥梁作用,氢键改善了无机填料与树脂的相容性,这与以往改性剂与碳酸钙反应生成酯酸钙固化物的机理是不同的。     

玻璃纤维/乙烯基酯树脂复合材料在硫酸溶液中的腐蚀机理研究

采用称重法、电感偶合等离子发射光谱(ICP)、近红外光谱(NIR)、扫描电子显微镜(SEM)研究了玻璃纤维/乙烯基酯树脂复合材料(GF/VE)在不同温度的去离子水和硫酸溶液中的质量变化率、离子析出行为、树脂基体的水解行为以及腐蚀相态,并进一步分析了腐蚀机理。结果表明,在硫酸溶液中浸泡1800h时间内,仅在高温75℃浸泡的复合材料切割边缘封边处发现界面腐蚀,其他温度下腐蚀仅仅停留在树脂基体水平,纤维/树脂间界面仍然保持良好状态。     

新型不饱和聚酯—二甲苯不饱和聚酯树脂的制备与应用

本文对二甲苯不饱和聚酯树脂(2608树脂)的合成工艺和性能应用作了介绍。由试验得到二甲苯树脂和马来酸的最佳配比为100:343,在反应后期添加4.4%的甘油和4.4%的二甲苯甲醛树脂,可提高树脂韧性、耐水耐碱性能,并可降低成本100元/吨。树脂通过氧化环巳酮-萘酸钻,在20℃固化40～60分钟。产品可用手糊、缠绕、模压成型,主要用于耐硫酸、硝酸、盐酸、氢氟酸、氢氧化钠、Cr_2O_3等酸碱交替腐蚀的条件下。该材料还具有优良的高频绝缘性和机械性能,在电气工业中可代替环氧和硅橡胶。     

Al(OH)3对含水凝胶阻燃不饱和聚酯性能影响

制备了不同含量Al(OH)3的含水凝胶阻燃不饱和聚酯树脂(HCUP),并对其分散相的形貌、力学性能及其阻燃性能进行了研究.结果表明,水凝胶和Al(OH)3微粒可以均匀地分散在UPR(不饱和聚酯)中.Al(OH)3含量从0到90份(基础树脂为100份)的HCUP的拉伸强度、弯曲强度、冲击强度都表现出下降的趋势;Al(OH)3含量增加时,HCUP的阻燃性得到较大提高,表现为极限氧指数(LOI)从35%提高到51%,Al(OH)3使HCUP的热释放速率、有效燃烧热和质量损失速率都显著降低.     

低酯基密度乙烯基酯树脂耐碱性能研究

对低酯基密度双酚A型乙烯基酯树脂(MFE 711型)在80℃碱溶液中的腐蚀性能进行研究,同等实验条件下与其他类型树脂耐腐蚀性能进行对比,碱液介质为质量分数为25%的氢氧化钠(Na OH)溶液。试验证明低酯基密度乙烯基酯树脂在高温条件下具有优异的耐碱性能,经25%Na OH浸泡600 d,弯曲强度保留率为75%,弯曲模量保留率为105%,质量保留率为98.6%,有效厚度变化率小于0.5%,巴柯尔硬度保留率为108%。     

PVAc改性水泥砂浆耐化学腐蚀性能

采用聚醋酸乙烯酯(PVAc)乳液制备改性水泥砂浆,研究了PVAc改性砂浆经硫酸、硝酸、氢氧化钠、硫酸钠和汽油腐蚀后的强度残留比,并通过扫描电镜(SEM)观测了砂浆的微观形貌,采用X射线衍射仪(XRD)分析了经腐蚀后砂浆的物质组成.结果表明:水泥砂浆耐硫酸、硝酸腐蚀性能较差,但PVAc乳液可有效改善砂浆的耐酸腐蚀性能;PVAc乳液可一定程度改善水泥砂浆的耐硫酸盐酸腐蚀性能;高含量PVAc改性砂浆可应用于碱性环境;油污对普通水泥砂浆和聚合物水泥砂浆腐蚀效果均不明显;PVAc乳液胶膜可填充水泥砂浆的内部孔隙,有效阻塞了腐蚀介质进入,同时,PVAc胶膜具有弹性,可吸收膨胀应力,降低了膨胀破坏发生,从而改善砂浆的耐腐蚀性能.     

UV固化工艺制备新型聚氨酯丙烯酸酯人造大理石

以PUA(聚氨酯丙烯酸酯)为基体、炭黑和白炭黑为颜填料,采用UV(紫外光)固化工艺制备出一种新型PUA类人造大理石。研究结果表明:新型人造大理石将传统的成型过程及表面处理环节整合为一步法,极大简化了传统人造大理石的生产工艺;PUA本身具有良好的耐擦伤性、柔韧性、撕裂强度、光学性能和耐候性能,引入炭黑和白炭黑后可进一步增加涂层的硬度和抗冲击强度;以炭黑和白炭黑作为基本色,通过调节两者比例可配制出不同灰度的涂层,并且涂层的基本性能不受影响;该人造大理石具有良好的耐干热性能、耐化学腐蚀性能和耐污染性能,其光泽度为89%～92%,并且表面平整、光滑、饱满且装饰效果极好。     

磷渣基人造大理石的实验研究

以磷渣为主要原料,研究磷渣粉与粉煤灰和熟石灰的质量比、水胶质量比、胶骨质量比、骨料组成等对磷渣基人造大理石性能的影响,采用SEM电镜和抗折抗压实验仪表征材料性能。结果表明：磷渣基胶凝材料各物料配比为m（磷渣粉）:m（粉煤灰）:m（熟石灰）=90:4:6,水胶质量比为0.18,胶骨质量比为1:1.5,骨料组成为m（炉渣）:m（细磷渣）:m（粗磷渣）=10:40:10,磷渣基人造大理石的抗压强度和抗折强度可以达到94.38 MPa和12.09 MPa,其抗压强度和抗折强度均高于天然大理石,可在广泛领域替代天然大理石使用,为磷渣的资源化利用开辟一条新的路径。     

矿物掺合料对碱式硫酸镁水泥耐硫酸盐腐蚀性能的影响

为了研究粉碱式硫酸镁水泥耐硫酸盐腐蚀性能,对不同材料组成的碱式硫酸镁水泥浸入水和硫酸钠溶液中各龄期抗折强度、抗压强度、质量变化及水化产物进行了分析.结果表明,在0.3 mol/L的硫酸钠溶液试验环境下,掺入粉煤灰对水泥抗折抗蚀性能改善较为显著,而掺入矿渣对水泥抗压抗蚀性能改善较为显著.掺入粉煤灰和矿渣的碱式硫酸镁水泥180 d的抗折抗蚀系数和抗压抗蚀系数与未掺加矿物掺和料的碱式硫酸镁水泥相比分别提高了0.61和0.15;掺入粉煤灰和矿渣的碱式硫酸镁水泥各龄期的吸水率均低于未加外掺料的碱式硫酸镁水泥的吸水率,同时粉煤灰和矿渣的掺入能有效抑制Mg(OH)2晶相的产生.     

复合材料耐低温耐腐蚀性能研究(Ⅲ)

研制了一种耐低温耐腐蚀树脂基复合材料,记为S2/EpD。S2/EpD复合材料采用自制环氧配方,以高强玻璃纤维(S2)为增强材料,通过湿法纤维缠绕成型制作复合材料单向板。S2/EpD单向板在低温(-40℃)的2种氟碳化合物(记为Fa、Fb)里分别浸泡1 000 h后,其单向板复合材料弯曲模量及复合材料外观无显著变化,S2/EpD复合材料单向板在Fa、Fb氟碳化合物里浸泡1 000 h后,弯曲强度保持率分别为78%和81%,弯曲模量保持率分别为98%和95%。     

Use of titanate to improve interfacial interaction and mechanical properties of polyethylene/artificial marble wastes composites

The resource utilization of artificial marble wastes (AMWs) is urgently needed for environmental protection as a large amount of artificial marble are used as construction material. Nevertheless, it still remains challenging to achieve high performance of AMWs-filled polymer composites due to their poor interfacial interaction with hydrophobic polyolefins. Here, the unsaturated resin residue on the surface of AMWs is employed to construct strong interfacial interaction with high-density polyethylene (HDPE) matrix to prepare mechanically robust polymeric composites by use of titanate coupling agent. The mechanical properties (with a tensile strength of 28.6 MPa and a flexural strength of 27.7 MPa) of the resulting composites are comparable to or even better than those of raw calcium carbonate-filled HDPE composites. This work will not only promote the recycling and reutilization of AMWs, but also provide a feasible way for value-added application of other polymeric wastes, such as waste printed circuit board, waste artificial turf, and so on.     

Deterioration of high-performance concrete subjected to attack by the combination of ammonium nitrate solution and flexure stress

The behavior of ordinary concrete and high strength concrete under a combinative effect of stress and chemical corrosion was studied in the present work. The concrete specimens were immersed in a variety of chemical solutions including 10%, 5%, 1% and 0.1% ammonium nitrate and simultaneously subjected to different flexural loads with load levels of 30%, 40% and 50% of their initial flexure strengths. The influences of the concentration of solutions, quality class of the concretes and load level of applied flexural stress on the strength of concretes were investigated. The relationships between life-time of the concrete and concentration of the solution, relative strength of the concrete and penetration depth of the ammonium nitrate solutions were determined. The mechanisms of stress corrosion of concrete exposed to ammonium nitrate solution and superimposed to a flexural stress was also discussed.     

Effect of Chemical Surface Modifications on the Properties of Alfa Fiber-Polyester Composites

Composite materials based on Alfa fibers and unsaturated polyester resins were manufactured by the hand layup technique. Mechanical properties of composites prepared form Alfa fibers collected from the region of Boussaada (Algeria), treated by various concentrations of NaOH solutions (1, 3, 6, 9, and 12%) during 24 h were found to be better than those of the untreated ones. The 6% NaOH-treated fibers composite showed maximum improvement in tensile strengths about 63% and the 9% NaOH treated fibers composite showed maximum improvement in flexural strength about 52%, respectively. The tensile modulus improved by 50.48%. The flexural modulus was also improved by 44.06% compared to the untreated Alfa fiber composite. FTIR characterization of Alfa fibers showed that the number of hydroxyl groups (OH) decreased and the crystallinity index increase by 16.60% after alkaline treatment. SEM observations on fibers' surfaces showed that the alkaline treatment improved the interface adhesion of fiber–matrix.     

Zirconia-strengthened yttria ceramics for plasma chamber applications

Yttria (Y₂O₃) is the most popular lining material for the inner walls of plasma chambers, owing to its well-known resistance against corrosion by reactive fluorinated plasma. Yttria has a relatively lower toughness and strength compared to alumina (Al₂O₃) and zirconia (ZrO₂). The present work aims to explore the strengthening and toughening of yttria by doping with zirconia, while retaining its good corrosion resistance. Ceramics with zirconia to yttria molar ratios of 2:8 and 5:5 (named 20ZY and 50ZY, respectively) were fabricated by pressure sintering in Ar atmosphere. The corrosion of the prepared ceramics in reactive fluorinated plasma (C₄F₈/CHF₃/Ar) was investigated and compared with that of yttria as a control. The results indicated that 20ZY exhibited excellent corrosion resistance, comparable to that of yttria, while the fracture toughness and flexural strength showed increases of 87% and 44%, respectively. 50ZY exhibited a further improvement in fracture toughness and flexural strength, but at the price of a much lower resistance against plasma corrosion. A percolation model was proposed to interpret the observed plasma corrosion behaviors.     

偶联剂处理对碱式硫酸镁晶须填充UP树脂浇铸体力学性能的影响

利用钛酸酯类偶联剂NDZ101、NDZ401和硅烷类偶联剂KH550、KH570对碱式硫酸镁晶须进行处理,研究了几种偶联剂及其加入比例对晶须填充不饱和聚酯树脂(UP)浇铸体力学性能的影响,并结合应力-应变曲线和SEM的图片,对试验结果进行了讨论。实验结果表明,采用偶联剂处理晶须可改善其填充UP树脂浇注体的拉伸强度、拉伸模量、弯曲模量和冲击强度。其中,采用2%KH570进行处理,拉伸强度改善幅度最高,可提高47.54%;采用3%NDZ101进行处理,拉伸模量和弯曲模量均获得最大幅度的提高,分别为65.99%和69.33%;而采用4%KH550进行处理,却可最大幅度地提高冲击强度,为29.21%。对弯曲强度而言,偶联剂处理总体上对其影响效果不如其它的力学性能那样明显。相对而言,硅烷类偶联剂的效果优于钛酸酯类的偶联剂。加入4%KH570和5%KH550时获得的弯曲强度最大,分别为54.43MPa和53.19MPa,较未处理的浇铸体弯曲强度分别提高了25.10%和22.25%,而采用NDZ101或NDZ401,弯曲强度值却基本上都下降。碱式硫酸镁晶须填充UP树脂浇铸体的断裂属于脆性断裂。