发热蓄热保暖舒适性纺织品的制备与性能研究

吸湿发热材料和相变微胶囊是当今发热蓄热调温纺织品研究的重要方向,将相变微胶囊涂覆到吸湿发热面料上制得调温复合面料,对其调温性能(热学性能、吸湿发热性能、升降温性能、带液率、表面形态)和服用性能(透气性、耐水洗性)做了测试研究。结果表明:随着微胶囊浓度和交联剂浓度的增加,复合面料的调温性能逐渐增强,服用性能略微下降,推测其机理可能为相变微胶囊吸收吸湿发热面料产生的热量达到调温效果。     

棉秆皮微晶纤维素相变调温纤维的基本性能

为了提高棉秆皮微晶纤维素纤维的热学和强伸性能,以石蜡为芯材,密胺树脂为壁材,氧化石墨烯为导热材料,采用原位聚合法,制备氧化石墨烯相变微胶囊,并通过湿法纺丝方法纺制棉秆皮微晶纤维素相变调温纤维。测试了含有不同氧化石墨烯质量分数的相变微胶囊的形态结构、热学性能、粒径大小,以及棉秆皮微晶纤维素相变纤维的形态结构、热学性能、强伸性能及甲醛含量。结果表明:加入质量分数0.2%的氧化石墨烯时,相变微胶囊相变焓达到82.97 J/g,包覆率为54.91%,耐热性能较优,其形态结构较圆润、规则;加入质量分数0.2%氧化石墨烯相变微胶囊占棉秆皮微晶纤维素质量的10%而制备的棉秆皮微晶纤维素相变纤维的热学和强伸性能较优,相变焓为2.446 J/g,纤维断裂强度为0.280 cN/dtex,纤维表面较光滑、均匀;此外测得相变纤维甲醛含量11.946 mg/kg,远小于婴幼儿纺织品(三岁内)为20 mg/kg的国家标准规定。     

蓄热调温纤维用DA@PMMA相变微胶囊的制备及表征

基于正十二醇(DA)相变温度(约22℃)处于人体最佳舒适温度18~28℃范围内,采用DA为相变芯材,聚甲基丙烯酸甲酯(PMMA)为包封壁材,通过原位聚合法制备蓄热调温纺织品纤维用DA@PMMA相变微胶囊,并对相变微胶囊的形貌、粒径分布、热性能及抗压性进行表征。结果表明:DA@PMMA相变微胶囊粒径分布集中于1.232μm附近;壁材表面光滑致密;相变温度为18.7~25℃,热焓值为92.3 J/g,芯材包封率为84.7%,且具有较好的抗压性;可用于制备蓄热调温纺织品纤维。     

聚氨酯/相变蜡蓄热调温功能整理剂的制备及其在棉织物上的应用

针对传统相变微胶囊后整理法制备蓄热调温纺织品时存在制备工序繁杂、效率低等难点,开发了一种简便快捷的后整理法。选用相变蜡、聚氧乙烯辛基苯酚醚-10(OP-10)乳化剂和水性聚氨酯为主要组分,经高剪切乳化制备蓄热调温功能整理剂,利用浸轧—焙烘方式对棉织物进行整理。优化乳化剂用量、相变蜡与聚氨酯配比及焙烘温度,并测定整理后棉织物及背心的蓄热调温性能。结果表明:当OP-10质量分数为5%,相变蜡与聚氨酯的质量比为1.5∶1,焙烘温度150 ℃时,整理剂在纤维表面原位成膜形成包裹纤维的蓄热调温薄膜,从而赋予棉织物蓄热调温功能;整理后棉织物具备蓄热调温功能,由其所制作的背心具有显著的蓄热调温功能。     

基于相变薄膜的蓄热调温棉织物的制备与性能

以相变蜡和水性聚氨酯为主要组分制备蓄热调温整理液,采用浸轧-烘焙方式制备蓄热调温棉织物。采用场发射扫描电子显微镜(FESEM)、光量热差示扫描量热仪(DSC)、热重分析仪(TG)、热红外成像仪和智能风格仪表征整理前后棉织物的表面形貌、热性能、调温性能、手感和透气性能。结果表明:经蓄热调温整理液整理后,棉纤维表面附着一层明显的相变薄膜,聚氨酯通过成膜形式包覆相变蜡;蓄热调温棉织物在30.14℃左右存在明显的吸热峰,相变潜热约为19.64 J/g,热稳定性良好,且在26.1℃～27.89℃范围内蓄热调温性能明显;相比于原棉织物,蓄热调温棉织物手感和透气性仍高达17.05 J/g;经5次洗涤后,蓄热调温棉织物的相变潜热略有下降。该蓄热调温棉织物在调温被、调温座垫等领域具有良好的应用前景。     

相变材料微胶囊在蓄热调温智能纺织品中的应用

将相变材料微胶囊通过纺丝法包埋于纤维内部,或通过浸轧法、涂层法等整理于纤维或织物的表面,是实现纺织品蓄热调温功能的一类重要方法,也是目前蓄热调温智能纺织品的研究热点之一。为此,总结了相变材料微胶囊化的反应机制和影响微胶囊性质的主要因素,以及这类微胶囊与纺织品的复合技术,系统介绍了相变材料微胶囊在蓄热调温智能纺织品中的应用现状,并指出其中存在的问题及解决的方法,从而为智能纺织品的开发与应用提供参考。     

微胶囊技术在蓄热调温整理上的研究

利用相变材料和微胶囊技术生产蓄热调温型智能纺织品将在改善人类穿着舒适性方面发挥重要作用。文章简述了微胶囊技术的发展历程,并从调温机理、整理方法、性能评价等方面对蓄热调温整理的研究进行了论述。     

微胶囊技术在蓄热调温非织造布壁纸上的应用

采用三聚氰胺-尿素-甲醛树脂(MUF)为壁材,相变材料正十八烷为芯材,通过原位聚合法制备微胶囊。配制相变微胶囊涂层液,采取干法涂层工艺将微胶囊涂覆在非织造布上,制成蓄热调温功能材料。针对新型调温壁纸研发中遇到的问题,通过扫描电子显微镜、测温仪、织物透气量仪等测试手段,探讨相变微胶囊整理工艺对材料厚度、透气性和调温性能的影响。测试结果表明,干法涂层工艺使微胶囊均匀地附着在壁纸表面,壁纸的厚度不发生明显变化,壁纸具有较好的透气性和良好的蓄热调温功能。     

相变调温纺织品制备方法的研究进展

为明晰制备工艺对调温纺织品性能的影响,综述了相变调温纺织品的2种制备方法:即在中空纤维中填充相变材料或将相变材料加入纺丝液制备相变纤维,再经织造形成相变织物;或者通过直接填充、表面整理、表面接枝改性等直接复合方式获得相变织物。分析认为:中空纤维填充法对选用的纤维材料要求较高;直接填充法工艺简单、操作方便,但会使纺织品舒适性变差;微胶囊纺丝和微胶囊表面整理的方法已实现工业化,但所得纺织品的焓值较低;静电纺丝法不易实现大规模工业化;表面接枝法能够实现相变材料与纺织品的耐久性结合,但工艺复杂繁琐;最后对相变材料的调温纺织品未来的发展方向进行了展望。     

蓄热调温织物低温防护过程的数值模拟

为提升普通织物的低温抵抗性能,将具有蓄热调温功能的相变微胶囊涂覆至织物表面制得蓄热调温织物,通过Fluent 软件对复合织物的低温防护过程进行模拟,在此基础上设置了蓄热调温织物的低温防护试验对模型的模拟精度进行检验,并模拟探究了微胶囊的相变潜热以及其在织物中所占的体积分数对蓄热调温织物低温防护性能的影响。结果表明:数值模拟结果可显示不同时间节点蓄热调温织物的温度场分布情况以及各区域的温度变化趋势,且试验结果与模拟结果的误差小于8.64%,该模拟结果可较为准确地再现蓄热调温织物的低温防护过程;当微胶囊的相变潜热由50 J/g增加至200 J/g时,织物的低温防护时间延长了70.1%;当微胶囊的质量分数由1%增加至5%时,织物的低温防护时间由214 s延长至388 s,同比提升了81.3%。     

熔纺双组分调温聚丙烯纤维

 以正构烷烃和聚合物相变材料为芯层,聚丙烯为纤维的皮层,采用双组份熔融复合熔融纺丝法制备储热调温纤维。采用扫描电子显微镜(SEM)、差示扫描量热仪(DSC)和单纤维电子强力仪等观察了纤维的形貌,研究纤维的热力学性能和物理机械性能。结果表明：纤维的结构致密,具有明显的皮芯分界,相变材料质量分数为28%时,纤维的热焓值可达到36~40J/g,对纤维进行2.75倍的牵伸后处理,断裂强度和伸长率分别为2.3cN/dtex和29%,可满足纺织服装的应用要求。     

Electrical conductivity of CNT/polysulfonamide composites

Carbon nanotube/polysulfonamide (CNT/PSA) composite spinning solutions with different CNTs contents were prepared using the physical blending method. The corresponding composite fibers were extruded through a set of wet spinning unit and the composite membranes were prepared using a digital spin-coating technique. The distribution of CNTs in PSA matrix and the crystalline structure of composite fibers were investigated by scanning electron microscope (SEM) and X-ray diffraction, respectively. The influences of CNTs on mechanical properties as well as electrical conductivity of PSA composites were also analyzed. In addition, the general effective media equation was chosen to explain the electrical conductivity behavior of the CNT/PSA composites. The experimental results showed that CNTs with low contents can be distributed evenly in PSA; the crystallization in PSA was promoted at low CNTs contents; the mechanical properties of composites can be improved significantly; and the electrical conductivity of composites increased obviously and the percolation threshold of the blending system was at about 3?wt%.     

储热调温纤维的研究进展(二)

<正>(上接本刊2011年第4期第6页)4储热调温纤维的性能评价目前较为广泛的是采用差示扫描量热分析仪测试纤维在体温上下的吸放热特性,从而区分储热调温纤维与常规纤维。也可将纤维加工成织物或非织造布,通过测试储热调温纤维织物和常规织物的相变性能[6,9,10,15]、内部温度差[9]、温度调节系数[27]、动态热阻[28]等评价其性能。     

Physicochemical and Mechanical Properties of Bambara Groundnut Starch Films Modified with Stearic Acid

The physicochemical and mechanical properties of biofilm prepared from bambara starch modified with varying concentrations of stearic acid (0%, 2.5%, 3.5%, 5%, 7%, and 10%) were studied. By scanning electron microscopy, bambara starch films modified with stearic acid (≥3.5%) showed a progressively rough surface compared to those with 2.5% stearic acid and the control. Fourier transform infrared spectroscopy spectra revealed a peak shift of approximately 31 cm^?1, suggesting the promotion of hydrogen bond formation between hydroxyl groups of starch and stearic acid. The addition of 2.5% stearic acid to bambara starch film reduced water vapor permeability by approximately 17%. Bambara starch films modified with higher concentration of stearic acid were more opaque and showed significantly high melting temperatures. However, mechanical properties of starch films were generally negatively affected by stearic acid. Bambara starch film may be modified with 2.5% stearic acid for improved water vapor permeability and thermal stability with minimal effect on tensile strength.     

Preparation and properties of polypropylene/clay nanocomposites for food packaging

Polypropylene (PP)/clay nanocomposites based on PP, organic clay (montmorillonite; MMT), and maleated polypropylene (MAPP) were prepared by melt compounding. The mechanical, thermal, morphological, and gas barrier properties of the resulting PP/clay nanocomposites were investigated at varying concentrations of the components for food packaging. The results revealed that the mechanical strengths, including tensile, flexural, and Izod impact strength, were increased for PP/clay nanocomposites compared to neat PP. The thermal properties showed a tendency for the melting and degradation temperatures to increase with the clay concentration. The effect of the compatibilizer was observed using scanning electron microscopy (SEM). The X-ray diffraction pattern of the nanocomposites revealed increased d-spacing of the MMT layers, indicating that the compatibility of neat PP and clay was improved by the addition of MAPP, and the intercalation and partial exfoliation of the layers. The use of clay increased the mobility distance of the gas molecules, leading to the oxygen permeability of neat PP being reduced by 26% to 55%.     

Structures and flammability properties of polyethylene terephthalate(PET) fibers containing encapsulated carbon materials

In this paper, carbon nanotubes (CNTs) and carbon microspheres (CMSs) have been microencapsulated to obtain microencapsulated carbon nanotubes (MCNTs) and microencapsulated carbon microspheres (MCMSs). Moreover, a series of PET fibers with CNTs/CMSs or MCNTs/MCMSs were prepared by melt spinning. Morphologic structures, mechanical, thermal, and flame retardant properties of MCNTs/MCMSs /PET fibers have been studied by TEM, SEM, electronic tension meter, DSC, TG, limiting oxygen index (LOI), and vertical flammability instruments. The results show that the tensile strength of MCNTs/MCMSs/PET fibers are increased because of better dispersion and compatibility of MCNTs/MCMSs in PET and enhanced orientation degrees of fibers, compared with CNTs/CMSs/PET fibers. Moreover, the highest values of mechanical properties are observed with 0.4 wt% content. Meanwhile, the MCNTs/MCMSs/PET fibers have good thermal stabilities and their fabrics have higher LOI value of 25.3%, reaching B1 class of China standard GB 17591-2006. Overall, this method endowed the MCNTs/MCMSs/PET fibers with the good mechanical and flame-retardant properties.     

熔融纺聚乳酸/聚丙烯纤维的制备及其性能

为提高聚乳酸(PLA)纤维的力学性能,采用聚丙烯(PP)与聚乳酸(PLA)通过熔融纺丝制备PLA/PP纤维,并借助差示扫描热量仪、热重分析仪、万能材料测试仪、纤维双折射仪对其热学性能、热稳定性、拉伸性能和纤维取向度进行表征。结果表明:PP的引入对PLA的玻璃化转变温度和熔融温度没有显著影响,但促进了PLA的结晶,结晶度提高了585.9%;随着PP质量分数的增加,PLA的热稳定性降低(特别是在初始分解阶段),但其残炭率提高,同时PLA/PP共混纤维的取向度提高,力学性能得到改善;当PP质量分数为20%时,PLA/PP共混纤维的取向度、断裂强度和断裂伸长率分别提高了55.6%,98.2%和44.4%。     

再生丝素纤维的湿法纺丝及其交联改性研究

以六氟异丙醇(HFIP)溶解再生丝素膜,通过湿法纺丝获得再生丝素纤维。再生丝素纤维经1-(3-二甲基氨基丙基)-3-乙基碳化二亚胺(EDC)和N-羟基丁二酰亚胺(NHS)作为交联剂进行后处理,利用扫描电镜(SEM)、红外光谱(FTIR)、X-射线衍射(XRD)、DSC热分析法、力学性能等表征方法研究和分析了牵伸和交联前后纤维聚集态结构和力学性能的变化。研究结果表明:再生丝素纤维经牵伸和EDC/NHS交联改性后,纤维直径变细为87μm,纤维内部结构以silk II结构为主;纤维的热稳定性提高,热分解峰峰值由281℃提高至288℃;纤维的断裂强度和断裂伸长率明显增大,分别达到1.41 cN/dtex和11.38%,表现出良好的柔韧性。     

超声与光催化作用对大豆蛋白/TiO_2复合膜抗菌特性的影响

采用光催化/超声预处理,结合涂膜法制备大豆蛋白/TiO_2纳米复合膜,分析光催化和超声预处理以及膜中TiO_2含量对复合膜性质的影响。当TiO_2含量低于2%时,扫描电子显微镜观察发现TiO_2纳米颗粒均匀地分散在大豆蛋白基质中,从而有效地改善复合膜的机械性能,降低膜的溶胀变形程度,提高膜的热稳定性,增强复合膜的抗菌活性。荧光光谱分析、红外光谱和X-射线衍射分析证实了大豆蛋白和纳米颗粒间以氢键为主要作用力,且光催化可进一步增强TiO_2颗粒与大豆蛋白链间交联作用,因而光催化复合膜的机械性能、热稳定性和抗菌活性均高于超声复合膜。但当TiO_2含量过高(2%)会加剧TiO_2间的自聚,导致复合膜机械性能下降、溶胀变形程度增大及荧光淬灭。因此光催化大豆蛋白/TiO_2纳米复合膜有望成为新型绿色抗菌包装材料。     

热处理对大豆分离蛋白稳定乳液包埋特性的影响

本实验通过喷雾干燥前对SPI溶液95℃1 5 min热处理及形成乳液后加入乳糖溶液制备粉末样品,并将部分干粉储存于RH 75%环境中记录其7 d内等温吸湿线,待吸湿稳定后得到湿粉样品,测定原始乳液及干、湿粉末复溶乳液的粒径大小分布,干、湿粉末的水分含量、包埋效率(ME)、溶解速率并用扫描电镜(SEM)观察其微观结构。结果表明热处理和加糖处理能显著提高喷雾干燥SPI稳定乳液的包埋效率,高达98.68%,相对于未经处理的SPI乳液包埋效率高出1倍以上,此外含糖粉末表现出良好的溶解性,但潮湿环境对其溶解性、包埋效率及微观结构有较大影响。