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以甘油/二缩三乙二醇(GP)为主增塑剂,N-甲基吡咯烷(NMP)辅助增塑剂,对聚乙烯醇(PVA)进行增塑改性,研究了增塑剂类别和配比对PVA的增塑效果。通过红外光谱分析(FTIR)研究了复配增塑剂与PVA间的相互作用,采用X射线衍射分析(XRD)、差示扫描量热分析(DSC)、热失重分析(TGA)表征了改性PVA的结晶性能和热性能,采用熔融指数仪和转矩流变仪研究了改性后PVA的热塑加工性能。结果表明:复配增塑剂能有效地破坏PVA自身的氢键,降低PVA的熔融温度和结晶度,改善PVA的热塑加工性能,并成功实现了改性PVA的注塑成型。通过注塑成型的PVA具有较好的力学性能,拉伸强度为28.6 MPa,断裂伸长率为534%。 相似文献
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以高熔点多元醇季戊四醇(TMM)为主增塑剂、辅以相容剂和润滑剂形成复配增塑剂,对聚乙烯醇(PVA)进行增塑改性,以增大温度加工窗口,提高其热稳定性,实现改性PVA的熔融加工成型。采用差示扫描量热仪(DSC)、热重分析仪(TGA)、熔体指数仪测试了改性PVA的热性能和流动性能;采用扫描X射线衍射(XRD)、电子显微镜(SEM)对其结晶结构与形貌进行了测试与观察;然后进行了力学性能测试。结果表明,高熔点多元醇增塑剂用于增塑PVA,具备降低PVA的熔点,提高分解温度,增加流动性,使改性PVA具有良好的熔融加工性能,可用于注塑与挤出加工,制品具备良好的力学性能。 相似文献
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Several modified poly(vinyl alcohol) (PVA) systems with various plasticizers were prepared and their melt‐processing was successfully realized. This paper focuses on the study of the evaporation behaviour of water in these modified PVA systems, exploring its plasticizing mechanism by using differential scanning calorimetry. The evaporation characteristics of bulk water, water in aqueous solutions of the plasticizers, and the thermal properties of PVA were also studied. The experimental results show that water in aqueous solutions of glycerol and/or caprolactam evaporates at a lower temperature than bulk water, but water in the PVA/water system evaporates at a higher temperature, with a wider DSC peak due to the interaction between water and PVA. Incorporation of glycerol, caprolactam or their mixtures further strengthens the interactions between water and the other components, retarding water evaporation. During the processing, the less closely associated water has the plasticizing effect through molecule movement, while the strongly bound water, which breaks the intermolecular hydrogen bonding of PVA and decreases its intermolecular interaction, is more beneficial to the melt‐processing of PVA. Copyright © 2003 Society of Chemical Industry 相似文献
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通过熔融挤出制备了低分子量PVA(PVA0599)改性PVA(PVA1799)共混材料,采用差示扫描量热法(DSC)、X射线衍射(XRD)和偏光显微镜(PLM)研究了PVA0599对PVA共混体系熔融结晶行为的影响,结果表明:低分子量PVA的加入降低了共混材料的熔点和结晶度,且随低分子量PVA含量的增加,共混材料的结晶速率先增加后减小,当加入20%的PVA0599时,结晶速率达最大。共混材料的球晶尺寸随低分子量PVA含量增加逐渐减小,低分子量PVA在一定程度上降低了PVA的结晶能力,抑制了其结晶。 相似文献
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淀粉/PVA生物降解材料的热塑性研究 总被引:4,自引:0,他引:4
将聚乙烯醇(PVA)、淀粉、增塑剂在Hakke流变仪中共混制备了热塑性淀粉/PvA材料,研究了2种PVA-PVA1799、PVA1788,2种淀粉-玉米淀粉、木薯淀粉的热塑性情况;比较了甘油、乙二醇、乙酰胺3种增塑剂的增塑效果.结果表明:采用合适的增塑剂与适当的PVA、淀粉组合可以使PVA/淀粉共混体系在高温下热塑成型... 相似文献
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The starch/polyvinyl alcohol (PVA) bioblend sheets containing urea and formamide as plasticizers were prepared through melt processing in presence of water. The experiments indicated that urea and formamide plasticizers could form strong hydrogen bonds with starch/PVA molecules. Urea exhibited better plasticizing effect than formamide. Urea also could greatly destroy the crystal structures of PVA component in the blends, leading to the decreased crystallinity of the blends. Formamide was a good solvent for urea and could prevent urea separating from the blends, resulting in the improved stability of plasticizing systems. The blends exhibited good flexibility. Therefore, the incorporation of both urea and formamide into starch/PVA blends could exhibit synergistic effects to ensure the blends with both good plasticizing effect and the stability of the plasticizing systems. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42311. 相似文献
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Three nontoxic carbohydrates (ribose, xylose, fructose) were used as poly(vinyl alcohol) (PVA) plasticizers to prepare PVA films using a casting method. Fourier transform infrared spectra demonstrated that hydrogen bonds formed between the carbohydrate and PVA. The crystallinity of raw PVA and PVA film plasticized by carbohydrate was characterized by X‐ray diffraction. Differential scanning calorimetry showed that carbohydrate decreased the melting point (Tm) of PVA. The decomposition temperature of PVA increased with addition of carbohydrate. The thermal stability of PVA film plasticized by carbohydrate (CAPF) was higher than that of PVA film plasticized by glycerol (GLPF). The thermal processing window of CAPF was broader than that of GLPF. The water vapor resistance of CAPF was better than that of GLPF. The mechanical properties of PVA films stored at different relative humidity were studied. Generally, the tensile strength of CAPF was larger than that of GLPF, while the elongation at break of CAPF was close to that of GLPF. Our experimental results indicate that carbohydrates are effective plasticizers for PVA. J. VINYL ADDIT. TECHNOL., 25:E181–E187, 2019. © 2018 Society of Plastics Engineers 相似文献
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采用熔融共混法制备了一种聚乙烯醇(PVA)/马来酸酐接枝聚丙烯(PP-g-MAH)共混物膜,通过差示扫描量热仪研究了共混物膜的结晶和熔融行为。结果表明,随着共混物中PP-g-MAH含量(不超过50 %)的增加,PVA相的结晶和熔融温度升高,结晶度增加,结晶速率增加,而随着PVA含量(超过30 %)的增加,PP-g-MAH的结晶及熔融温度降低,结晶度降低,结晶速率增加。用Ozawa法对共混物中PVA相的非等温结晶动力学研究表明,共混物中PVA相在191~197 ℃开始主期结晶,在173~189 ℃进入次期结晶阶段。 相似文献