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《应用化工》2022,(9):1850-1853
利用甲苯二异氰酸酯(TDI)和聚丙二醇(PPG)合成不同结构的端—NCO聚氨酯(PU)预聚体,然后由聚氨酯预聚体与环氧树脂进行接枝反应,制备聚氨酯改性环氧树脂。研究了聚氨酯预聚体结构和用量对改性环氧树脂力学性能的影响规律。结果表明,当聚醚多元醇选用PPG1000,且TDI∶PPG=2∶1时,制得的聚氨酯预聚体对环氧树脂的增韧效果最好,当ω(PU预聚体)=10%时,改性环氧树脂的应变和拉伸强度分别达到84. 7%和27. 1 MPa,是改性前的30. 47倍和3. 04倍。通过扫描电镜对聚氨酯的增韧机理进行了研究,发现改性前环氧树脂为脆性断裂,聚氨酯改性后的环氧树脂断裂时银纹明显增多,为韧性断裂。 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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橡胶增韧环氧树脂的新方法 总被引:3,自引:1,他引:2
本文讨论了液体端羧基丁腈橡胶增韧环氧树脂存在橡胶交联网络不完整问题,并进一步研究为克服此缺点而使用预制的橡胶微球(即活性微凝胶)作为环氧增韧剂的体系的表面化学性质、流变学性能、及以伯胺类固化剂固化的此体系的胶接强度及力学性能等。 相似文献
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聚醚增韧环氧树脂的机理研究 总被引:2,自引:0,他引:2
本文以2—乙基—4—甲基咪唑(24EMI)为固化剂研究了新型环氧改性剂一端羧基THF-PO共聚醚(CTCPE)对DGEBA/24EMI固化体系的增韧作用及CTCPE增韧环氧树脂的机理。结果表明,CTCPE使环氧树脂固化物韧性显著提高,添加量达30phr时断裂韧性、冲击强度达极大值,其增韧机理服从孔洞化一剪切屈服模型。 相似文献
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In this article, the structure and properties of the epoxy resin (EP) modified by polyurethane (PU) prepolymers were studied. The three types of polyurethane prepolymers, namely, polycarbonate-type PU (TPC), polyether-type PU, and polycarbonate–polyether-type PU were employed. The samples were analyzed by means of an infrared spectrometer, a differential scanning calorimeter, a scanning electron microscope, a transmission electron microscope, a scanning tunnel microscope, and a thermal gravimeter. The results show that the EP modified by TPC is of excellent thermal resistance and mechanical properties. Specifically, when the ratio of PU to EP is 10/100 (wt/wt), optimal properties are achieved. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 887–893, 1998 相似文献
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Bao‐Long Zhang Guang‐Liang Tang Ke‐Yu Shi Ying‐Cai You Zong‐Jie Du Ji‐Fu Huang 《应用聚合物科学杂志》1999,71(1):177-184
A series of novel reactive toughening agents (LCEUPPG) containing both a flexible spacer and rigid liquid crystalline unit were synthesized to modify the bisphenol epoxy resin/dicyandiamide curing system. The curing reactivity, apparent activation energy, curing mechanism, dynamic mechanical behavior, and impact strength of the modified system were systematically studied. Compared with the unmodified system, the results indicate that LCEUPPG have greatly accelerated the curing reaction between epoxy resin and dicyandiamide, reduced the apparent activation energy of the curing reaction, enhanced the impact strength 3–7 times, and maintained high dynamic modulus and good thermal properties. In addition, SEM observation of the fracture surfaces showed a two‐phase microstructure in the modified systems. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 177–184, 1999 相似文献
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Epoxy resin Epidian 5 cured with triethylene tetramine was modified with hydroxyl‐terminated polybutadiene (PB) and polycarbonate (PC). Compositions with different amount of modifiers were obtained and tested for their impact strength, flexural strength, as well as resistance to crack propagation. The latter was assessed by evaluating the critical stress intensity factor under three‐point bending mode using single‐edge notched specimens. Scanning electron microscopy was used to analyze the fractured sample surfaces. The obtained results revealed that the mechanical properties of epoxy resin were improved due to the formation of heterogeneous phase with rubber particles, which arrest the propagation of cracks. Moreover, synergism effect was observed with the hybrid composition containing 10% PC and 2.5% of reactive PB. The impact strength was higher by ~ 15% than the sum of impact strength of compositions containing only one modifier. Another hybrid composition with 2.5% PB and 2.5% PC also exhibited synergism effect with the flexural strain at break, the energy at break under flexure, as well as the brittle fracture energy estimated from the critical stress intensity factor measurements. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 相似文献
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The study on toughening and reinforcing of bisphenol-A epoxy resin is one of important developmental direction in the field.
This paper reports a one-pot synthesis of aromatic polyester hyperbranched epoxy resin HTDE-2, an effect of HTDE-2 content
on the mechanical and thermal performance of the bisphenol-A (E51)/HTDE-2 hybrid resin in detail. Fourier transform infrared
(FT-IR) spectrometer, scanning electronic microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis
(TGA), dynamic mechanical thermal analysis (DMA) and molecular simulation technology are used to study the structure of HTDE-2,
performance and toughening and reinforcing mechanism of the HTDE-2/E51 hybrid resin. It has been shown that the content of
HTDE-2 has an important effect on the performance of the hybrid resin, and the performance of the HTDE-2/E51 blends has maximum
with the increase in HTDE-2 content. The impact strength and fracture toughness of the hybrid resin with 9 wt-% HTDE-2 are
almost 3.088 and 1.749 times of E51 performance respectively, furthermore, the tensile and flexural strength can also be enhanced
about 20.7% and 14.2%, respectively. The glass transition temperature and thermal degradation temperature, however, are found
to decrease to some extent.
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Translated from Journal of South China University of Technology (Natural Science Edition), 2006: 34(9): 90–94 [译自: 华南理工大学学报 (自然科学版)] 相似文献
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The relationship between the mechanical properties and morphology of polyhexamethylene carbonate diol (PHMCD) toughened epoxy resin was investigated. The parameters describing the morphology (e.g., average diameter of particles and volume fraction of dispersed phase, etc.) were determined through SEM observation. It was observed that the particle size distribution changes from a unimodal distribution to a bimodal one and then tounimodal again with an increase in curing temperature. When it was cured at 120°C, an epoxy resin with a bimodal distribution of rubber particle size was obtained. The mechanical properties, especially the impacting strength, of the resin are the best because of the synergistic effect of the PHMCD particles. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 569–575, 1998 相似文献
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The curing kinetics and the glass transition behavior of amino-polycarbonate with diglycidyl ether of bisphenol-A epoxy resin systems were studied by differential scanning calorimetry (DSC). The ASTM E-698 method was chosen to determine the kinetics parameters of the curing reaction, including the activation energy, preexponential factor, rate constant, and 60-min half-life temperature. The amino-polycarbonate was able to accelerate the curing reaction, reduce the apparent active energy, and decrease Tg of the systems. A homogeneous amino-polycarbonate/epoxy resin network was observed in scanning electron microscopy (SEM) pictures. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 833–838, 2001 相似文献
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Considerable improvements in the fracture resistance of epoxy resins have recently been achieved by adding either rubbery or rigid second phase dispersions, or both, to an epoxy matrix. These multiphase epoxy systems are particularly useful as high performance adhesives and as matrix materials in advanced composites. This paper describes the development of new toughened epoxy hybrids, which contain both rubbery and rigid dispersions. The latter dispersions were either zirconia particles, short alumina fibres or glassy-metal ribbons. Micromechanisms of toughening and failure processes in these new materials are identified and discussed in the light of microstructures. 相似文献
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