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壳聚糖-葡甘聚糖共混改性的研究 总被引:1,自引:1,他引:0
对壳聚糖-葡甘聚糖共混改性进行了研究,并对共混膜的力学性能、透气性、透过率进行一系列的性能测试.实验结果表明:壳聚糖与葡甘聚糖在共混膜中存在强烈的相互作用及良好的相容性;共混膜的力学性能随葡甘聚糖含量的增加而得到明显提高,当壳聚糖/葡甘聚糖的体积比为7/3,甘油添加量为15%(质量分数,后同)时,共混膜的各项性能达到最优. 相似文献
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可食性明胶-魔芋葡甘聚糖共混膜的制备与性能研究 总被引:1,自引:0,他引:1
采用溶液共混法制备了一系列不同比例的明胶-魔芋葡甘聚糖共混膜,研究了明胶含量(质量分数)对共混膜的力学性能、吸湿性能、透光性能的影响。结果表明,明胶的引入,有利于改善魔芋葡甘聚糖膜的力学性能,减小魔芋葡甘聚糖膜的吸水率,明胶与魔芋葡甘聚糖的相容性良好。 相似文献
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以魔芋葡甘聚糖和羧甲基纤维素钠为主要原料,添加丙三醇为增塑剂,乳酸为改性剂,结合微波处理工艺,采用流延成型的方法制备出魔芋葡甘聚糖/羧甲基纤维素钠共混膜。通过FT-IR、X-射线衍射对共混膜进行性能表征,同时测定了共混膜的吸水率、力学性能和降解率。结果表明:膜有较好的降解性能和细胞相容性,作为一种潜在的术后防粘连材料将具有良好的应用前景。 相似文献
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为研究魔芋葡甘聚糖的改性,采用振动机械力化学的方法对魔芋葡甘聚糖进行脱乙酰基和酯化改性。结果表明,在振动机械力化学处理时,魔芋葡甘聚糖分子结构中的活性基团与碱性改性剂发生皂化反应,可以快速有效地脱去乙酰基;碱性改性剂的碱性越强,脱乙酰基改性的效果越好;脱乙酰基的魔芋葡甘聚糖样品具有较好的黏度稳定性,并随着改性时间的延长而增强。在振动磨机械应力作用下,魔芋葡甘聚糖中的羟基可被磷酸盐基团取代发生酯化反应;经酯化改性,魔芋葡甘聚糖水溶胶的透光率优于原料,吸附金属离子量与原料相比较高。在改性时间为10 min时经酯化改性的魔芋葡甘聚糖样品的透光率和吸附性达到最佳值。魔芋葡甘聚糖大分子链的完整性对其絮凝能力的影响大于磷含量的影响。 相似文献
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魔芋葡甘聚糖/羧甲基淀粉共混膜及其阻水性能 总被引:12,自引:0,他引:12
用溶液共混法成功地制备出魔芋葡甘聚糖 /羧甲基淀粉共混膜 ,并用 IR、XRD、SEM、力学性能和水蒸汽透过率测试研究了其结构和性能。结果表明 ,共混膜中魔芋葡甘聚糖和羧甲基淀粉存在强烈的分子间氢键相互作用及良好的相容性 ;共混膜的拉伸强度及阻水性能随羧甲基淀粉的加入而显著提高。当羧甲基淀粉的含量为 2 0 %时 ,共混膜的拉伸强度达最大值为 67.1MPa,比纯魔芋葡甘聚糖膜的拉伸强度提高了 191.7% ;共混膜的阻水性能也最佳 ,其水蒸汽透过率为 86.4 mg/ cm2 .d,比纯魔芋葡甘聚糖膜的水蒸汽透过率下降了 2 6.4 %。该共混膜作为一种潜在的可食性包装材料将具有广阔的应用前景 相似文献
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以石英玻璃为摩擦副,研究在面接触条件下魔芋葡甘聚糖溶液的水基润滑特性。使用红外光谱仪测量了魔芋葡甘聚糖的分子结构,用多功能摩擦磨损试验机进行润滑特性试验,用LEXT OLS4000 3D激光共聚焦显微镜表征了试样的表面形貌,重点分析了不同浓度魔芋葡甘聚糖溶液的润滑特性。结果表明:浓度为0.3%的溶液具有最佳的润滑性能,石英玻璃间的摩擦系数约为0.002。在不同浓度的魔芋葡甘聚糖溶液的润滑条件下,摩擦副的摩擦系数随着转速呈现出不同的变化规律。由于硼酸离子与魔芋葡甘聚糖分子中的羟基发生化学反应生成硼酸多羟基化合物,硼酸的加入增强了水合分子层的稳定性。魔芋葡甘聚糖水基润滑界面,主要包含魔芋葡甘聚糖水合分子层和自由水分子层。水合分子层吸附在摩擦副表面形成吸附膜可避免摩擦副的直接接触,自由水分子层保证了润滑液的剪切流动性,两者的共同作用实现了有效润滑。 相似文献
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魔芋葡甘聚糖/Ⅱ型胶原/壳聚糖复合材料的制备及性能 总被引:1,自引:0,他引:1
以魔芋葡甘聚糖、Ⅱ型胶原和壳聚糖为主要原料,采用36%的乙酸溶解壳聚糖、Ⅱ型胶原的甘油溶液通过共混的方法制备魔芋葡甘聚糖/Ⅱ型胶原/壳聚糖共混膜液,经静置减压脱泡、倒模、干燥制膜,并采取与乙酸等量的氢氧化钠对膜进行处理。用FT-IR、XRD、生物学显微镜和SEM对共混膜进行性能表征,测定了共混膜的透光率、力学性能、吸水率及水蒸气透过系数,还做了复合材料的细胞相容性实验,主要进行了骨髓间充质干细胞、牙周膜成纤维细胞的体外培养,另外对膜进行了体外模拟降解实验。结果表明其有望作为一种潜在的皮肤组织工程支架材料和牙周膜材料。 相似文献
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目的研究影响聚乙烯醇-魔芋葡甘聚糖包装膜透光率和雾度的因素。方法以甘油、山梨醇为复配增塑剂,将纯化过的魔芋精粉和聚乙烯醇按一定质量比混合后水浴恒温共混,流延干燥制备包装膜,研究共混温度、共混时间、基料配比、复配增塑剂配比对包装膜透光率和雾度的影响。结果魔芋精粉和聚乙烯醇按质量比为1∶10混合,在水浴温度80℃下恒温共混3 h,加入质量分数为10%的复配增塑剂,复配增塑剂中山梨醇和甘油的质量比控制在1∶2~1∶3时制备的包装膜透光率和雾度达到最佳。结论各因素对包装膜的透光率和雾度有较大影响,原因是它们能促使魔芋葡甘聚糖分子和聚乙烯醇分子形成强烈的协同作用。 相似文献
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目的:研究室温下葡甘聚糖涂布纸箱对芒果的保鲜效果,并确定葡甘聚糖的最佳浓度及涂布量。方法:将芒果存放入涂有不同浓度(0.50%、0.75%、1.00%、1.25%、1.50%)及不同涂布量(5m L/dm~2、10m L/dm~2、15m L/dm~2)的葡甘聚糖涂布纸箱中,通过测试样品的失重率、硬度、可溶性固形物含量,并与空白纸箱对照,分析确定葡甘聚糖的最佳浓度及涂布量。结果:葡甘聚糖涂布纸箱对芒果有一定的保鲜效果,试验样品的失重率、硬度、可溶性固形物含量的变化速度明显低于空白对照组。结论:葡甘聚糖涂布纸箱的最佳浓度为1.50%,最佳涂布量为10m L/dm~2。 相似文献
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本文简单介绍了中子射源水份分析仪在高炉焦炭水份检测仪表系统中的应用工作原理,并叙述系统在衡阳华菱钢管炼铁分厂1080m3高炉配料焦炭水份量检测的应用实例。文章较大篇幅介绍了中子水分仪仪表的标定,说明其日常维护重点就是仪器的标定。 相似文献
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The effect of moisture and temperature on liquid water transport in porous media was studied. Specimens of autoclaved aerated concrete were subjected to one-sided water penetration in isothermal conditions at temperatures of 20 °C, 40 °C, 60 °C, and 80 °C. After specified time intervals, moisture profiles were determined gravimetrically. The moisture diffusivity was calculated for a particular temperature as a function of moisture content, using an inverse analysis. The results demonstrate the dependence of the moisture diffusivity on the moisture content and the temperature of the samples. The moisture diffusivity for high moisture content can be as much as one order of magnitude greater than for the lowest moisture content studied. The moisture diffusivity was found to increase by as much as a factor of two when the temperature is increased from 20 °C to 80 °C. 相似文献
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Measurement Techniques - A dielectric moisture meter is described in which moisture content is determined from the phase shift angle between the increments in the total conductivity of the... 相似文献
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目的 研究对比陶制直镀内衬纸与常规直镀内衬纸的防潮保润保香性能。方法 对镀陶和常规直镀内衬纸进行SEM,BET和透湿率及透氧率检测,并将2种内衬纸卷制的成品卷烟放置于高温高湿、干燥、常温常湿等条件下平衡85 d,随后对拆包不同时长的卷烟进行烟支含水率检测,同时采用静态顶空气相色谱-质谱联用仪测定卷烟滤棒及烟丝中香精的主要成分含量。结果 与常规直镀内衬纸相比,镀陶直镀内衬纸的表面致密性和比表面积明显较优,且其氧气透过率略小,水蒸气透过率较小。在高温高湿和干燥条件下,镀陶样品的烟支含水率与初始设计值较为接近;在常温常湿条件下,2种内衬纸包装的烟支含水率虽在拆包前30 h无明显区别,但在35 h后,常规直镀内衬纸包装的烟支含水率显著下降,不满足设计要求。结论 镀陶直镀内衬纸的防潮效果较好、保香效果较好、保润效果略好。镀陶烟用内衬纸的工艺还有待进一步调整,以进一步提高其防潮保香保香效果。 相似文献
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For measuring the moisture content of concrete various methods— beside the gravimetric method— are available which differ from one another with respect to their suitability and reliability. In the preparation of some research program authors are confronted with the problem to carry out measurements of the moisture content in rather large concrete bodies partly at elevated temperatures over prolonged periods of time. In order to obtain a general view of the state of experience with the individual methods a survey was carried through among institutes working in this field, with the essential help of RILEM. Its result with reference to the relevant literature is reported. 相似文献
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De-Shin Liu Zhen-Wei Zhuang Shaw-Ruey Lyu Cho-Liang Chung Pai-Chen Lin 《计算机、材料和连续体(英文)》2011,26(2):111-136
This study proposes a two-dimensional heterogeneous hybrid moisture element method (HHMEM) for modeling transient moisture diffusion in permeable fiber-reinforced polymer composites.
The HHMEM scheme is based on a heterogeneous hybrid moisture element(HHME), with properties determined through an equivalent hybrid moisture capacitance/conductance matrix. This matrix was calculated using the conventional finite element formulation in space discretization as well as the θ-method in time discretization with similar mass/stiffness properties and matrix condensing operations. A coupled HHME-FE scheme was developed and implemented in computer code MATLAB in order to analyze the transient moisture diffusion characteristics of composite materials containing multiple permeable fibers. The analysis commenced by comparing the performance of the proposed scheme with that of conventional FEM to model the moisture diffusion process. Both hexagonal and square fiber arrangements were studied. Having validated its performance, the scheme was then employed to investigate the relationship between the volume fraction of the permeable fibers in the resin composite and the rate of moisture diffusion. It was found that the moisture diffusion was significantly retarded as the volume fraction of the fibers increased. The HHMEM approach proposed in this study provides a straightforward and efficient means of modeling transient moisture diffusion in composite materials containing multiple permeable fibers. This is because only one HHME moisture characteristic matrix of fibers requires calculation for all HHMEs sharing the same characteristics. Furthermore, varying volume fractions can be modeled without modifying the original model simply by controlling the size of the inter-phase region within the HHME domain. 相似文献
The HHMEM scheme is based on a heterogeneous hybrid moisture element(HHME), with properties determined through an equivalent hybrid moisture capacitance/conductance matrix. This matrix was calculated using the conventional finite element formulation in space discretization as well as the θ-method in time discretization with similar mass/stiffness properties and matrix condensing operations. A coupled HHME-FE scheme was developed and implemented in computer code MATLAB in order to analyze the transient moisture diffusion characteristics of composite materials containing multiple permeable fibers. The analysis commenced by comparing the performance of the proposed scheme with that of conventional FEM to model the moisture diffusion process. Both hexagonal and square fiber arrangements were studied. Having validated its performance, the scheme was then employed to investigate the relationship between the volume fraction of the permeable fibers in the resin composite and the rate of moisture diffusion. It was found that the moisture diffusion was significantly retarded as the volume fraction of the fibers increased. The HHMEM approach proposed in this study provides a straightforward and efficient means of modeling transient moisture diffusion in composite materials containing multiple permeable fibers. This is because only one HHME moisture characteristic matrix of fibers requires calculation for all HHMEs sharing the same characteristics. Furthermore, varying volume fractions can be modeled without modifying the original model simply by controlling the size of the inter-phase region within the HHME domain. 相似文献