蓄温隔热毛纺织品的研制与热性能测试

相变材料是一种能根据外界温度变化,通过吸热、放热的方式自发地改变状态的材料,也是制作调温材料的重要原料。为了研制具有蓄温隔热性能的纺织品,采用微胶囊技术将相变石蜡包覆于密胺树脂中制成相变微胶囊,并利用浸渍的方式将相变微胶囊整理到织物上来制备调温织物。文章探讨了整理剂质量分数对织物调温效果的影响;采用DSC测试分析后整理织物的热效应。研究表明,整理剂质量分数为11.57%的织物较原织物其相变焓较高且能达到较理想的相变温度,调温效果也优良。     

纺织相变纤维调温性能差示扫描量热法的检测影响因素

纺织相变纤维的重要指标之一是温度调节能力，但目前我国对于其温度调节能力并无统一的测试方法和评价方式。采用差示扫描量热仪（DSC）对相变纤维进行测试，研究升温速率、样品质量对相变焓值和相变温度的影响，并验证DSC设备在检测过程中的可重复性。结果表明，DSC方法可以很好地表征纺织相变纤维的调温性能，可重复性良好，随着升温速率的增大和样品质量的增加，相变温度升高，相变焓值也存在差异，通过结果对比分析得到较优的测试条件。     

智能调温纺织品的研究进展及调温性能初探

讨论了Outlast相变纱线和织物以及国产相变纱线及织物的研究进展;通过采用差示扫描量热(DSC)测试、电镜测试以及温度时间曲线的测试方法对上海第三十六棉纺针织服装厂研制的SL粘胶型相变调温纤维、纱线及织物的相变特性进行了初步探索。     

相变材料在调温纤维上的应用

利用溶胶-凝胶复合相变材料(A/SiO2),并用DSC对其热性能进行了测试。考察了水/酯摩尔比、反应温度、搅拌速度、pH值、陈化温度、酯/相变材料摩尔比等因素对胶凝时间及纤维调温性能的影响,筛选出最佳工艺。采用涂层法将复合相变材料整理到织物上。结果表明:复合后相变材料具有较高相变焓;复合相变材料的相变焓、相变温度均较纯相变材料稍有降低;织物经相变材料涂层整理后具有良好调温性能。     

微胶囊相变材料PCM在织物上的应用

相变材料微胶囊PCM采用浸轧法对纯棉和涤纶织物进行整理,用DSC法和织物透气仪测试调温织物的储热和透气性能。最优整理工艺为：采用两次一浸一轧的方式、相变材料微胶囊的用量为250 g/L、烘干温度为110 ℃,烘干时间为120 s。DSC热分析表明：调温织物的升温和降温速率较普通织物显著减缓,具有智能调温功能,且调温织物的透气性有所增加。通过此方法可以制备得到具有调温功能的织物,具备一定的耐洗性能,且在涤纶织物上效果略佳。     

制备参数对温控复合织物性能的影响

为开发一种三明治结构的温控复合织物,使用静电纺丝法制备的相变纳米纤维膜作为织物的中间层,使用黏胶织物及羊毛织物分别作为织物的内外层。利用扫描电镜(SEM)和差式扫描量热仪(DSC)分别表征相变纳米纤维膜的形貌和热性能,考察相变材料的含量及相变纳米纤维膜的厚度对温控复合织物保温性和透气透湿性的影响。结果表明:相变纳米纤维膜中纳米纤维呈圆柱形,纤维表面不光滑并有折皱,其熔融相变温度为28.02℃;相变材料的含量越多、相变纳米纤维膜的厚度越大,则温控复合织物的保温性能越好,但其透气透湿性能有所下降。     

SL相变调温纤维混纺织物调温性能研究

研究国产SL相变调温纤维混纺针织物的调温性能.采用差示扫描量热法、平板织物保温测试仪法和温度曲线法对混纺织物的调温性能进行了测试与分析.结果表明,SL相变调温纤维混纺织物在高于熔融相变温度环境中具有吸热现象,表现为升温速度较慢;而在低于结晶相变温度环境中具有放热现象,表现为降温速度较慢.指出:SL相变调温纤维混纺织物在一定温度下具有较明显的调温性能.     

抗性淀粉热性质分析[Ⅰ]

采用热失重法(TG)和差示扫描量热分析技术(DSC)对松谷Fibersol2抗性淀粉进行热性质分析。TG曲线显示该抗性淀粉在293.85℃开始分解,312.37℃分解速度最快,330.89℃是分解的最终温度。DSC吸热曲线显示,样品在24.36℃左右开始出现吸热峰,相变高峰温度约在98.54℃(相变焓179.1J/g),另外在204.23℃和225.48℃出现两个小的吸热峰,表明样品以支链晶体结构为主。     

知名抗性淀粉的热性质分析[Ⅱ]

采用热失重法(TG)和差示扫描量热分析技术(DSC)对罗盖特Nutriose?抗性淀粉进行热性质分析。TG曲线显示该抗性淀粉在296.73℃开始分解,314.77℃分解速度最快,332.81℃是分解的最终温度。DSC吸热曲线显示,样品第一次分析曲线在29.04℃出现吸热峰,在61.64℃出现冷结晶放热峰,在74.67℃左右开始出现吸热峰,相变高峰温度约在81.92℃(相变焓267.1J/g),另外在219.89℃出现小的吸热峰;分析系统经快速降温后,样品的第二次分析曲线在31.22℃开始出现吸热峰,相变高峰温度约在86.39℃(相变焓38.97J/g),在218.70℃仍然出现一个小的吸热峰,冷结晶吸热峰消失,表明样品经过热处理后,晶体结构发生变化。     

相变材料在热防护服上的应用研究进展

为深入了解和提高附加相变材料热防护服的热防护性能,对现阶段相变材料在热防护服中的应用、影响因素以及未来研究趋势进行综述.首先介绍了相变材料的类型和特点,阐述了相变材料基于密封袋法、纺丝法和微胶囊技术的织物后整理法在热防护服中的应用;其次回顾了附加相变材料热防护服传热模型的发展过程,重点从相变材料的类型、相变温度、添加量...     

聚乙二醇及其二元体系的相变行为

利用差示扫描量热法对不同分子质量聚乙二醇(PEG)及其二元体系进行测量和分析,以表征其相变行为及特征和PEG1000与PEG2000二元混合体的组分比对相变行为的影响。实验结果表明,相变能和相转变温度受PEG分子质量和组分比的影响PEG1000/PEG2000比较适合作为调温蓄热纺织品的工作物质;PEG二元体系受分子质量的影响,在升温方向存在双峰现象;PEG相变行为可以通过调整其二元体系的组分比来达到对相变能和相转变温度的精确控制。     

DSC enthalpic transitions during starch gelatinisation in excess water,dilute sodium chloride and dilute sucrose solutions

BACKGROUND: Starch phase transition characteristics were studied by pre‐treating starch samples in excess water, dilute sodium chloride and dilute sucrose solutions and subjecting them to differential scanning calorimetry (DSC). Unmodified maize, wheat and potato starches were held at specific temperatures between 30 and 90 °C for 30 min and promptly cooled to 25 °C. Treated samples were then analysed in situ by DSC. RESULTS: It was found that the progression of the phase transition behaviour differed among the three starches and was dependent on the solvent. It was also revealed that phase transition‐related enthalpic changes started to occur at low temperatures and that this process involved a continuous sequence of structural changes, resulting in progressive differences in endothermic patterns from low to high temperatures. CONCLUSION: These findings are in agreement with recent evidence suggesting that starch gelatinisation occurs over a wider temperature range rather than as a sudden order–disorder transition taking place within a narrow temperature range. The phase transition mechanism is determined by starch type and solvent combination. Copyright © 2009 Society of Chemical Industry     

用差示扫描量热法分析明胶品质

通过对明胶凝胶强度和明胶相变时焓变值的测定,研究明胶的凝胶强度与其相焓值的关系,试图找出明胶品质与相变的内在联系.利用差示扫描量热法(DSC法)分别对5种明胶凝胶和溶液的相变参数进行测定,结果表明:降温时,明胶溶液的焓变值与其凝胶强度间存在指数关系;升温时,明胶凝胶的焓变值与其凝胶强度存在指数关系;溶化并降温时,明胶凝胶的焓变值与相变起始温度存在线性关系,与明胶凝胶强度存在极度显著的线性关系.结果表明,利用差示扫描量热法法测定明胶凝胶的相变焓值,同样可以准确表征明胶的品质,并且样品用量极小.     

海藻酸钠-壳聚糖相变储热微胶囊的制备

海藻酸钠和壳聚糖都是价廉环保的天然高分子材料,具有广阔的应用开发前景。以海藻酸钠-壳聚糖为壁材,复合醇为芯材,通过乳化固化法制备出相变储热微胶囊,解决了脂肪醇在相变过程中的泄露问题。探讨了芯材用量、碳酸钙用量、乳化体系和壳聚糖浓度等对微胶囊储热性能的影响,利用扫描电镜、激光粒径分析仪、DSC和测试步冷曲线等手段对微胶囊进行表征。结果表明,制得微胶囊的相变温度为37.9℃,调温区间为37.9~40.8℃,相变潜热为52.8J/g,芯材包封率为44.7%。     

玉米淀粉在水-离子液体混合溶液中的相转变机制研究

利用差示扫描量热法(differential scanning calorimetry,DSC)、傅里叶红外光谱(Fourier transform infrared,FTIR)、激光共聚焦显微拉曼光谱(laser confocal micro-Raman,LCM-Raman)、X-射线衍射技术(X-ray diffraction,XRD)和扫描电子显微镜(scanning electron microscopy,SEM)等手段,研究不同摩尔比的水/离子液体(ionic liquid,IL)混合液对玉米淀粉结构和性质的影响,揭示玉米淀粉在水:离子液体混合溶液中的相转变机制。结果表明,随着IL浓度的增加,淀粉的凝胶化转变为从单个吸热峰、到先有小的放热峰后紧接着吸热峰、再到单个放热峰的过渡趋势。在DSC相转变的起始温度下,淀粉多尺度结构没有发生明显的破坏。加热温度在凝胶化相转变的峰值温度时,淀粉结构都有显著破坏。加热温度在DSC终止温度时未观察到淀粉的残余有序结构,表明淀粉完全发生凝胶化,综上表明加热温度在淀粉多尺度结构变化过程中起关键作用。     

Ni-Ti形状记忆合金纤维相变的电阻特性

相变温度是决定形状记忆合金纤维的加工与使用的重要性能参数。以Ni-Ti合金纤维为例,为研究其相变过程中温度与电阻之间的关系,基于纤维内部马氏体生长模型和电阻的混合定律,建立了Ni-Ti合金的电阻特性模型,研究了自由状态下Ni-Ti纤维电阻率与温度之间的关系。设计电阻法温度测量装置及信号采集系统,对自由状态下的Ni-Ti纤维进行测试,通过对纤维电阻率-温度曲线求导,测得Ni含量为55.5 a.t.%纤维试样的四个相变温度分别为Ms=34.4℃,Mf=25.6℃,As=39.4℃,Af=51.1℃,与纤维DSC法测试结果对比发现：通过电阻、温度的同步测量可以有效地探测纤维的相变,相变温度可通过电阻率-温度导函数准确标定。     

乌桕类可可脂晶型衍变与胀罐的关系

研究不同冷却结晶条件下CTCBE和CB的晶型衍变与胀罐的关系。采用差示扫描量热仪(DSC)、X-射线衍射仪(XRD)对不同结晶条件下两种可可脂样品进行热分析及晶相分析研究。结果表明未经调温CTCBE缓冷时中心样存在十分严重晶型衍变(粉状物,DSC测试显示双熔点峰),引起晶体结构的改变,导致胀罐发生;而急冷时晶型衍变程度低,不导致胀罐。同样条件下CB晶型衍变程度极低(DSC测试显示单熔点峰),不发生胀罐。经调温处理CTCBE急冷和缓冷对XRD晶相衍射数据基本无影响;而未经调温处理CTCBE在急冷和缓冷时两者晶相衍射数据存在一定差异。调温与未经调温CB在缓冷或急冷时的X-射线衍射数据均具有一致性。     

Effects of Malting on Phase Transition Behaviour of Starch in Barley Cultivars with Varying Amylose Content

The effect of malting on the phase transition behaviour of starch in barley cultivars with varying amylose content was studied using differential scanning calorimetry (DSC). A slight elevation in the melting transition temperature of amylopectin of malt starch and a pronounced decrease in gelatinisation enthalpy for both malt flour and starch were observed for all samples. Evidence was provided from the calorimetric data and the ¹³C CP/MAS NMR spectra that starch-lipid interactions in the form of complexes are enhanced as a result of malting. There was also a large reduction in the melting transition temperature of the amylose-lipid complexes of malt flours, presumably due to partial degradation of amylose in malt, whereas the transition enthalpies of the complexes increased for both malt flours and starches. The DSC transition characteristics of the three good malting barley cultivars grown in different locations and of their respective malts showed that environmental conditions during starch synthesis have a great influence on starch granule organization, and thereby affect the thermal stability of amylopectin crystallites.     

相变微胶囊整理棉织物的结构与性能

为研制具有蓄热调温功能的织物,将微胶囊相变材料(MPCMs)整理到棉织物上,通过SEM、FT-IR、DSC及织物强力仪等测试手段测定整理前后棉织物的结构与性能。结果表明:MPCMs可被均匀地整理到棉织物表面,MPCMs整理对棉织物的微细结构不产生影响;经MPCMs整理后棉织物可以吸收一定的热量,整理后棉织物的热分解温度和熔融热焓值均较整理前提高;织物升温曲线表明经MPCMs整理后,织物具有优异的调温性能;整理后的棉织物经、纬向断裂强度均提高,透气性能有一定程度的下降。     

Determination of the Crystallization Behavior of Lipids by Temperature Modulated Optical Refractometry

This study was conducted to examine if the new temperature modulated optical refractometry (TMOR) method is applicable to study the phase behavior of alkyl-based components. n-Hexadecane, palmitic acid, and glycerol tripalmitate were used as model components. TMOR was benchmarked against differential scanning calorimetry (DSC) and polarized light microscopy (PLM). For all substances, a good agreement of the DSC data with TMOR was found. For n-hexadecane, a difference of 2.2 °C for the crystallization and 2.6 °C for the melting temperature was found. Considering palmitic acid, the crystallization temperature differed by 3.3 °C while the melting varied by 2.8 °C. The crystallization temperature of tripalmitate identified by TMOR was 2.7 °C higher, and the melting temperature 2.3 °C was lower compared to the DSC. The crystallization temperature for TMOR was always higher, and the melting temperature was always lower if related to DSC. This leads to the conclusion that TMOR is more accurate and direct. In addition, the transition peaks identified by TMOR were narrower compared to the DSC peaks. This is due to slower heating and cooling rates leading to a smaller temperature range of phase transition and less thermal lag. The study showed that TMOR is an appropriate method to determine the phase transition temperatures for the three examined substances. The results were comparable to the DSC data in both melting and crystallization behavior. Since the accuracy of TMOR is better at lower heating and cooling rates, it could be a reasonable extension of the well-known DSC method in the studies of melting and crystallization.