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《玻璃钢/复合材料》2020,(4)
硬质聚氨酯泡沫塑料具有低密度、低导热系数和优良的隔热保温性能,但耐热性较差,需提高其耐热性以满足应用要求。本文使用羟基硅油(PDMS)对聚氨酯进行改性,并添加低熔点玻璃粉、滑石粉和高岭土等填料,采用模压成型工艺制备可瓷化PDMS改性聚氨酯泡沫复合材料,研究了高岭土对可瓷化PDMS改性聚氨酯泡沫复合材料压缩强度、导热系数和耐热性能等的影响。结果表明:随着高岭土含量的增加,材料的密度增大,导热系数变大,压缩强度提高;SEM结果显示,800℃处理后材料表面生成一层陶瓷化连续相结构;XRD分析表明新生成的陶瓷相为α-石英和斜方锰顽辉石。因此,无机填料的添加有效地提高了硬质聚氨酯泡沫塑料的耐热性。 相似文献
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《塑料工业》2017,(9)
以氯铂酸为催化剂,通过五甲基二硅氧烷与端羟基聚丁二烯的硅氢加成反应,首次合成出以聚丁二烯为主链、侧链含硅氧烷的改性端羟基聚丁二烯。研究了硅氧烷改性的端羟基聚丁二烯作为聚氨酯软段对泡沫疏水性及吸油性能的影响。结果表明,硅氧烷接枝聚丁二烯作为聚氨酯软段可以有效地降低聚氨酯弹性体的表面能从而提高其疏水性,聚氨酯弹性体与水的接触角从未改性的84.6°提高到108°,硅氧烷接枝聚丁二烯制备的聚氨酯泡沫的与水的接触达到了158°;由于硅氧烷接枝聚丁二烯与甲苯、汽油和柴油的相容性较好,泡沫在吸附甲苯、汽油和柴油的过程中伴随着孔的填充的同时致使基体溶胀,从而可以有效地提高泡沫的吸附倍率。 相似文献
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以经过丙烯酰氯改性的端羟基聚丁二烯液体橡胶、铝粉、氯化钾、过氧化苯甲酰(BPO)、光引发剂819作为原料制备了光热双重固化橡胶材料。分析测试了改性端羟基聚丁二烯液体橡胶光热双重固化材料的断裂拉伸强度和吸水率。讨论了光引发剂用量对材料力学性能、吸水性的影响。实验结果表明,随着光引发剂使用量的增加,橡胶材料的断裂拉伸强度降低,吸水能力变差。使用6份和10份光引发剂的光热双重固化材料分别显示了最大断裂拉伸强度(0.69MPa)和最小断裂拉伸强度(0.61MPa),最高吸水率(49.20%)和最低吸水率(25.92%)。 相似文献
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《聚氨酯工业》2019,(5)
以不同密度的硬质聚氨酯泡沫塑料作为隔离层,以D-803-Z型丁腈橡胶为阻尼层,制成一系列用于控制结构振动的聚氨酯-橡胶隔离复合阻尼材料。采用动态热机械分析法(DMA)分析了聚氨酯硬泡和橡胶材料的动态力学性能,并通过锤击实验从幅频曲线、复合损耗因子、模态频率等方面将敷设隔离复合阻尼材料的悬臂梁与橡胶自由阻尼悬臂梁进行了对比分析,探讨了4种不同密度的聚氨酯泡沫对隔离复合阻尼悬臂梁减振性能的影响。结果表明:聚氨酯泡沫损耗因子相对较小,其主要作用是扩大阻尼层的形变;相比于自由阻尼悬臂梁,隔离复合阻尼悬臂梁的前三阶模态振动响应降低了8%~52%,复合损耗因子提高了2~3倍;随着聚氨酯泡沫密度的增大,各阶模态的振动响应持续降低。聚氨酯-橡胶隔离复合阻尼材料能够有效降低结构的振动,适当提高聚氨酯泡沫层的密度有助于进一步改善材料的减振性能。 相似文献
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端羟基聚丁二烯液体橡胶的特性和应用 总被引:2,自引:0,他引:2
刘学英 《化学推进剂与高分子材料》1985,(3)
一、前言端羟基聚丁二烯(以下简称为 HTPB或丁羟胶)是分子链端含有羟基的预聚物。因其在常温下是液体,又可通过链延长、交联固化成为在结构与性能上与固体橡胶相近的弹性体,故也有人称其为“液体橡胶”。鉴于该弹性体中常含有氨基甲酸酯链,故又常将其归在聚氨酯类。众所周知,在制备聚氨酯材料时,除异氰酸酯外,另一重要组份是多元醇。在目前广泛使用的多元醇中,除天然化合物外,就是由合成获得的端羟基聚酯和聚醚等,故可认为丁羟胶是制备聚氨酯材料的多元醇组份之一,不妨称由丁羟制得的聚氨酯为聚丁二 相似文献
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概述了聚丁二烯液体橡胶的常见种类和特性,阐述了端羟基聚丁二烯液体橡胶、端羧基聚丁二烯液体橡胶和端羟羧基聚丁二烯液体橡胶的特性及应用,介绍了聚丁二烯液体橡胶的研究进展。 相似文献
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《精细化工原料及中间体》2015,(10)
<正>聚氨酯泡沫塑料是异氰酸酯和羟基化合物经聚合发泡制成,按其硬度可分为软质和硬质两类。一般来说它具有极佳的弹性、柔软性、伸长率和压缩强度;化学稳定性好,耐许多溶剂和油类;耐磨性优良,较天然海绵大20倍;还有优良的加工性、绝热性、粘合性等性能,是一种性能优良的缓冲材料,但价格较高。聚氨酯泡沫保温塑料是一种综合性能良好的新型建筑保温材料,在国外已广泛应用于外墙外保温, 相似文献
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通过添加淀粉和由淀粉合成的乙二醇葡萄糖苷共混改性,以改善硬质聚氨酯泡沫塑料的物理力学性能,研究了聚醚(PAO)、二苯甲烷二异氰酸酯(MDI)和复合催化剂的配比及淀粉和糖苷的加入量对改性硬质聚氨酯泡沫塑料的影响,并对发泡工艺进行了改进。正交试验结果表明:制备改性硬质聚氨酯泡沫塑料的最佳质量配比为PAO∶MDI∶复合催化剂=100∶125∶2,当淀粉加入量为PAO质量的45%,乙二醇葡萄糖苷加入量为PAO质量的40%时,制备的改性硬质聚氨酯泡沫塑料的压缩强度提高了38%,密度提高了47%,而且具有较好的弹性和耐水性。 相似文献
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Aqueous polyurethane (PU) adhesives are nontoxic and nonflammable and do not pollute the air. However, they have low adhesive strengths compared to solvent‐based PU adhesives because of a low affinity with rubber substrates. In this study, PU adhesives were synthesized from isophorone diisocyanate with dimethylol propionic acid as the ionic center in the main chain, triethylamine as the neutralization agent, and hydrazine as the chain extender. The polyol was modified with hydroxyl‐terminated polybutadiene (HTPB) and hydroxyl‐terminated acrylonitrile–butadiene copolymer (HTBN). The effect of the HTPB and HTBN content on the adhesive strength was investigated. The effect of the prepolymer molecular weight was also investigated. Increases in the HTPB and HTBN contents led to an increase in the adhesive strength because of the increase of chemical affinity between the adhesive and the substrate. The adhesive strength increased as the prepolymer molecular weight increased. This was due to an increase in the tensile strength and modulus. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1062–1068, 2005 相似文献
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黄玉西;田春蓉;梁书恩;王建华 《中国塑料》2012,26(1):59-64
用大豆油多元醇替代石化聚醚多元醇制备出了硬质聚氨酯泡沫塑料(RPUF),考察了石化聚醚多元醇和大豆油多元醇的比例以及RPUF密度对RPUF性能的影响。结果表明,随着大豆油多元醇用量的增加,RPUF的冲击强度和压缩模量减小,压缩屈服点逐渐消失,玻璃化转变温度升高;但随着大豆油基RPUF密度的增加,其冲击强度、压缩模量和储能模量都得到了提高,压缩模量最高可达56.44 MPa。 相似文献
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膨胀石墨填充硬质聚氨酯泡沫塑料的研究 总被引:4,自引:0,他引:4
对膨胀石墨(EG)填充硬质聚氨酯泡沫塑料(RPUF)泡孔结构和填料分散情况进行了分析,研究了EG对RPUF的微观结构形态、泡孔平均直径和泡孔直径分布的影响;同时研究了EG对RPUF的压缩力学性能和电学性能的影响,并分析其压缩破坏的机理。结果表明:EG使RPUF泡孔平均直径减小,泡孔尺寸分布减小,EG在反应体系中充当泡孔成核剂,石墨片层间距离小,并未形成插层复合结构。随EG用量的增加,RPUF的压缩强度和压缩模量轻微下降。不同膨胀倍率的EG对其压缩强度和压缩模量没有影响;EG填充RPUF的体积电阻没有变化,对其导电性能没有影响。 相似文献
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以高顺式端羟基液体顺丁橡胶(HTPB)为改性剂,分别采用共混-共固化法、共缩聚法制备了共混改性型不饱和聚酯[UPR+HTPB(blend)]、无规共缩聚改性型不饱和聚酯(UPR-HTPB)和嵌段共缩聚改性型不饱和聚酯(UPR-MAH-HTPB),系统地考察了三种改性不饱和聚酯固化样品的机械物理性能。结果表明,三种改性不饱和树脂的断裂伸长率、拉伸强度和冲击强度均优于未改性的不饱和树脂,固化收缩率大幅降低,且共缩聚改性树脂(UPR-HTPB和UPR-MAH-HTPB)的增韧效果和降收缩效果明显优于共混改性树脂。此外,UPRMAH-HTPB的拉伸模量也优于未改性的不饱和树脂,硬度和热变形温度则基本保持不变。冲击断面的形貌、交联密度和DMA分析表明,UPR+HTPB(blend)固化体系中存在着HTPB聚团的现象,而共缩聚改性树脂,尤其是嵌段型的UPR-MAH-HTPB,因HTPB嵌入到UPR的主链中,使HTPB微相分离,并更多地参与交联,在增韧的同时保持了树脂良好的刚性和强度。 相似文献
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Hydroxyl-terminated polybutadiene (HTPB) has been modified with azido-containing substances to be applied in propulsion systems. Pristine HTPB has compatibility issues with energetic polar substances and plasticizers, which is a drawback to develop new high-energy propellants. This work presents a path for the functionalization of HTPB, carried out through a controlled bulk reaction of it with octyl-1-azide. Then it was reacted with isophorone diisocyanate with or without dioctyl adipate (DOA). Structural, thermal, rheological, and dynamic-mechanical assessments were accomplished. Infrared revealed the arising of absorption bands associated to the CN stretching. From 13C and 1H nuclear magnetic resonances, it is possible to deduce the presence of amine, aziridine, and imine chemical groups, which may promote compatibilization with other polar and energetic substances. The chemical modification induced an increase of viscosity. With respect to the glass–liquid and glass–rubber transitions, the modification shifted them slightly to higher temperatures, but created stiffer networks, in agreement with the increase of polarity and chain interaction due to the presence of N-containing functionalities. Regarding the solid elastomer binder, the storage shear modulus and molecular mobility were influenced by the type of HTPB and DOA content. In general, the modified HTPB has physical properties like pristine HTPB. 相似文献
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介绍了含活性官能团的聚丁二烯系列液体橡胶 (以下简称PBLR)的品种、性能及特点 ;概括比较了PBLR改性增韧环氧树脂的方法及特点 ;分别列举了PBLR改性环氧树脂在微电机浇注料、树脂砂轮、水利机械涂敷、电子灌封及飞机粘合剂等方面的应用。 相似文献
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In the present study, hydroxyl‐terminated polybutadiene (HTPB) liquid rubber was employed to modify epoxy resin using 2,4,6‐tri (dimethylaminomethyl) phenol as a catalyst, and methyl hexahydrophthalic anhydride as a curing agent. The reactions between HTPB and epoxy were monitored by Fourier transform infrared (FTIR); the mechanical and dielectric properties of HTPB modified epoxies were evaluated and the morphology was investigated through scanning electronic microscopy (SEM). The FTIR analysis evidenced the occurrence of a chemical reaction between the two components. The mechanical results indicated that the impact strength of HTPB‐modified epoxy was superior to that of the pure epoxy. As the HTPB content increased up to 10 phr the best mechanical performances in terms of tensile and flexural properties were achieved when compared to the unmodified epoxy. Higher concentration of HTPB resulted in larger particles and gave lower mechanical strength values. The incorporation of HTPB into epoxy decreased the dielectric constant and dissipation factor over a wide frequency range from 1 to 106 Hz, and improved the electrical resistivity. SEM micrographs showed that the modified epoxy exhibited a two‐phase morphology where the spherical rubber domains were dispersed in the epoxy matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
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反应性端基聚丁二烯系列液体橡胶在环氧树脂改性增韧方面的应用 总被引:5,自引:0,他引:5
综述了含反应性端基聚丁二烯系列液体橡胶(以下简单PBLR)品种、性能及特点,概括比较了PBLR改性增韧环氧树脂方法及特点;分别列举了PBLR改性环氧树脂在微机电浇注料,树脂砂轮,水利机械涂敷,电子灌封及飞机粘合剂等方面的应用。 相似文献
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Yurun Yang Yongmin Huang Yonglin Chen Dening Wang Honglai Liu Chunpu Hu 《应用聚合物科学杂志》2004,91(5):2984-2991
A series of polyurethane (PU) films made from toluene diisocyanate (TDI), 1,4‐butanediol (BDO), and hydroxyl‐terminated polybutadiene (HTPB), hydroxyl terminated polybutadiene/styrene (HTBS), or hydroxyl terminated polybutadiene/acrylonitrile (HTBN) was synthesized by solution polymerization. The absorption of benzene vapor was found mainly in the soft phase. The equilibrium adsorption (M∞) was reduced with increasing hard segment content for all the PUs. The values of M∞ were in the sequence of HTBN‐PUs > HTBS‐PUs > HTPB‐PUs, which could be explained by the different interaction parameters between soft segments and benzene. The HTBN‐PU film showed the lowest degree of phase segregation and had more hard segments intermixed in the soft phase, restricting the movement of soft segments, and therefore resulted to non‐Fickian behavior, while the HTPB‐PU is antithetical. FTIR and atomic force microscopy were utilized to identify the hydrogen bonding behavior and morphology change of the PU films before and after the absorption of benzene vapor. The tensile strength of the HTBN‐PUs showed a greater decrease than that of HTBS‐PUs and HTPB‐PUs after absorbing benzene vapor. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2984–2991, 2004 相似文献