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聚氨酯一聚丙烯酸酯共聚乳液的合成研究 总被引:4,自引:0,他引:4
以甲基丙烯酸β-羟乙酯封端的聚氨酯大分子单体与丙烯酸酯类单体进行乳液共聚,合成了以聚丙烯酸酯(PA)为主链、聚氨酯(PU)为侧链的接枝共聚物(PA-g-PU)乳液,用IR光谱和^1H NMR光谱对该聚氨酯大分子单体及PA-g-PU接枝共聚物进行了表征,并对影响聚氨酯-聚丙烯酸酯共聚合的因素进行了探讨。结果表明:聚氨酯大分子单体的加入对乳液聚合的速率造成较大的影响。该体系的表观活化自由能为99.39KJ/mol,Rp∝[I]^0.87,Rp∝[S]^0.12。 相似文献
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《化学研究》2016,(3)
以自制的聚酯多元醇(PPMBA)、甲苯二异氰酸酯(TDI)、1,6-六亚甲基二异氰酸酯(HDI)、二羟甲基丙酸(DMPA)合成聚氨酯预聚体,再用丙烯酸酯类单体代替有机溶剂对预聚体降黏,封端预聚体后中和分散乳化得包含丙烯酸酯类单体的聚氨酯乳液.向乳液中加入引发剂引发自由基聚合得到复合乳液,最后再加入乙烯基类单体及引发剂合成三层核壳结构的聚丙烯酸酯/聚氨酯复合乳液.研究表明,二异氰酸酯的-NCO与聚酯多元醇中的-OH的物质的量之比(R值)为1.6~4之间时,随R值增加,乳液稳定性增强;DMPA含量在4%~7%的范围内,随DMPA含量的降低,乳胶膜的耐水性提高.通过红外光谱对所合成聚酯多元醇及复合乳液结构进行表征. 相似文献
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采用种子溶胀乳液聚合法,以水性聚氨酯为种子,甲基丙烯酸羟乙酯、甲基丙烯酸甲酯和丙烯酸丁酯为单体制备水性聚氨酯丙烯酸酯复合乳液,考察了甲基丙烯酸羟乙酯含量对复合乳液的T型剥离、胶膜的硬度、耐水性和力学性能的影响。结果表明,随着甲基丙烯酸羟乙酯含量的增加,复合乳液的T型剥离强度、胶膜的硬度和拉伸强度增大,胶膜的耐水性先增大后减小,断裂伸长率有所降低,适宜的甲基丙烯酸羟乙酯用量为3%。 相似文献
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核—壳结构聚丙烯酸酯—聚氨酯微乳液膜的相行为 总被引:5,自引:0,他引:5
用动态力学、红外光谱和差热分析方法研究了非交联核-壳结构聚丙烯酸酯-聚氨酯(PAC-PU)微乳液膜的相行为.结果表明:核壳间的氢键增强了壳层软硬段间的相分离,同时破坏了硬段相中的短程有序结构,但增强了核壳相容性 相似文献
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The vinyl group terminated water-borne polyurethanes (WPU) with different DMPA content were prepared. Subsequently the core-shell polyurethane/polyacrylate (PUA) composite emulsions were synthesized by soap-free emulsion copolymerization. The WPU as sole surfactant was used in copolymerization, and the lowest surface tension could be achieved to 38.8?mN m?1. Furthermore, the final conversion of acrylic monomer was reached to 98% in the case of WPU reactive seed. The FTIR-ATR indirectly confirmed the core-shell structure of PUA, simultaneously combined with DSC results found that the compatibility of WPU and PA was enhanced by growing grafting efficiency. The TEM results further indicated that the amount of DMPA in WPU had a great significant role in polymerization and final morphology structure. The PUA composite particles changed from scattered structure, core-shell structure to multi-core structure with increasing DMPA content. Correspondingly, the reinforcing and toughening effects were also found in PUA films with the increase content of DMPA by tensile testing. 相似文献
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Comparative study between core-shell and interpenetrating network structure polyurethane/polyacrylate composite emulsions 总被引:2,自引:0,他引:2
Anionic aqueous polyurethane dispersion was prepared by using carboxyl acid group to make the polyurethane dispersible, and then nanograde core-shell and crosslinked IPN structure polyurethane/polyacrylate composite latex (PUA) were synthesized by soap-free emulsion polymerization method with polyurethane dispersion as seed. FTIR, DSC, dynamic light scattering, TEM, ESCA, TGA, electronic tensile machine were employed to investigate the structures and properties of the composite latex and their polymers. Meanwhile the core-shell composite PUA emulsion and the crosslinked IPN composite PUA emulsion were compared. The results showed that the particle morphology of PUA composite emulsion is inverted core-shell structure with polyacrylate as the core and with polyurethane as the shell. The morphology of the crosslinked PUA emulsion was multi-core structure. The surface in core-shell PUA contains rich PU phase. The phase structure of the crosslinked PUA is more uniform. Three transition temperatures are observed for the core-shell composite PUA, two transitions are observed for the film from the crosslinked PUA. The TGA curves of core-shell PUA and crosslinked PUA exhibit two stages, the first stage corresponds to the thermal decomposition of hard segments in seed polyurethane; the second stage corresponds to the decomposition of soft segments in PUA and decomposition of polyacrylate. With the increase of glycidyl methacrylate (GMA) amounts in PUA composite emulsions, the tensile strength of the PUA films as well as the average diameter of the PUA composite emulsion particles increase, the elongation at break of the PUA films decreases. 相似文献
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采用丙烯酸酯(AC)对水性聚氨酯(WPU)进行改性,合成了接枝型丙烯酸酯/聚氨酯(PUA)复合乳液。 随着共聚物中丙烯酸酯质量分数的增加,乳液外观由透明变为不透明,乳液粒径随之增大、分布变宽。 TEM显示,PUA乳胶粒子呈现清晰的核壳结构,且形态规整,粒径分布在60~120 nm之间。 FTIR测试表明,随着丙烯酸酯质量分数的增加,聚氨酯(PU)硬段氢键化作用先增强后减弱,硬段的有序度逐渐降低。 DSC分析表明,当AC的质量分数低于75%时,PU、聚丙烯酸酯(PA)两组分相容性较好,只出现一个玻璃化转变温度,并且随着PA质量分数的增加逐渐升高。 PA质量分数的增加,使胶膜的最大热失重速率从363 ℃提高至412 ℃,吸水率从11.3%降低至5.7%,弹性模量从16.4 MPa提高至47.6 MPa,拉伸强度从9.0 MPa提高至23.7 MPa,断裂伸长率从365%提高至408%,同时乳液的粘度下降,干燥时间变短,胶膜的附着力变好。 相似文献
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丙烯酸酯改性水性聚氨酯乳液的制备及性能研究 总被引:10,自引:0,他引:10
采用共聚的方法制备出丙烯酸酯改性的水性聚氨酯共聚乳液(PUA乳液),并对PUA乳液的制备方法和工艺、耐溶剂性、机械稳定性进行了初步的研究。结果表明,具有IPN结构的PUA乳液耐溶剂性、机械稳定性比水性PU有明显的提高。 相似文献
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Aqueous acrylic-polyurethane (PUA) composite emulsion was prepared by soap-free seeded emulsion copolymerization. Waterborne polyurethane (WPU) was used as the seeded emulsion and functioned as surfactant. The effect of molecular weight of WPU on the heterogenic was investigated. The molecular weight of WPU was controlled by varying the NCO/OH mole ratio. The GPC results confirmed that the molecular weight of WPU presented double distribution. And the molecular weight of WPU decreased with the increasing NCO/OH mole ratio. Surface tension test indicated that the molecular weight had little influence on the surface activity of WPU. However, after emulsion copolymerization of acrylic monomers, the morphology and properties of the PUA composite were impacted markedly by the molecular weight of WPU. With an increase in the NCO/OH mole ratio, the morphology of PUA composite latex changed from core-shell structures to fish bowl structure, and the mechanical properties of PUA films changed correspondingly. 相似文献
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以甲基丙烯酸甲酯(MMA)、可聚合乳化剂马来酸酐衍生物磺酸钠(M12)和可聚合紫外线吸收剂2-羟基-4-(3-甲基丙烯酰氧基-2-羟基丙氧基)苯甲酮(BPMA)为原料,采用乳液聚合方法制备了P(MMA-M12-BP-MA)共聚物乳液。通过转化率、红外光谱、以及紫外吸收光谱测定,分别研究了M12含量对聚合反应速率的影响、所得共聚产物的结构、以及共聚物乳液和共聚物紫外吸收特性。结果表明,随M12含量增大,聚合反应速率增加;BPMA含量增大有利于提高共聚物乳液和共聚物紫外吸收性能。 相似文献
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Based on the solvent-free method, novel fluorinated polyurethane/polyacrylate hybrid emulsions, dodecafluoroheptyl methacrylate (DFMA) as fluorinated monomer, were successfully prepared via emulsion polymerization without traditional emulsifier. For the purpose of increasing the grafting ratio of polyurethane and polyacrylate, 60Co γ-ray radiation polymerization had been adopted to enhance the hardness of latex film. The chain structure and polymerization progress were confirmed by the analysis of Fourier transform infrared spectroscopy. The grafting ratio of polymethyl methacrylate and polyurethane was obtained by calculating the ratio of N–H peak integral area and Ph(C=C) peak integral area. The effect of DFMA content on thermal stability, mechanical property and water resistance were investigated systematically by thermal weight loss analysis, tensile strength test, absorbed water ratio and water contact angle. 相似文献
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Xuejun Cui Shuangling Zhong Haitao Zhang Qiang Gu Junfeng Li Hongyan Wang 《先进技术聚合物》2007,18(7):544-548
Polytetrafluoroethylene (PTFE)‐polyacrylate core–shell nanoparticles were produced by using PTFE micropowder and acrylate via seeded emulsion polymerization in the presence of fluorosurfactant. The properties of emulsion under various polymerization conditions were investigated and optimized. The chemical composition of the PTFE‐polyacrylate nanoparticles was characterized by Fourier‐transform infrared spectrometry (FTIR). The particle size and core–shell structure of the resulting PTFE‐polyacrylate nanoparticles were confirmed by transmission electron microscopy (TEM). Wettability of the PTFE‐polyacrylate core–shell particles was higher than the pristine PTFE. The formation of this kind of PTFE‐polyacrylate core–shell nanoparticles could improve the compatibility of PTFE with other materials because PTFE is covered by polyacrylate shell, which make them promising in various fields. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献