聚乙二醇/纤维素相变材料的制备及性能表征

以微晶纤维素（MCC）为原料，制备纤维素海绵（Cell），并以其作为基体，通过物理共混的方法与聚乙二醇（PEG）PEG-6000进行复合，制备聚乙二醇/纤维素相变材料（PCMs），研究了PCMs的结构与相变储能性能。实验结果表明：PCMs中PEG的质量分数可以达到90.77%，且相变过程中不会发生液体泄漏的问题。FT-IR分析表明纤维素基体和PEG之间存在明显的氢键作用，无新化合物产生。XRD分析结果表明：与纯PEG-6000相比，纤维素基体的加入不会改变PEG的结晶形态，但会降低PEG的结晶度。DSC结果表明，PCMs的熔融焓（ΔH_f）随着PCMs中PEG质量分数的增加而增大，ΔH_f最高可达146.88J/g（PCM₅），但均小于纯的PEG（179.09J/g）；PCMs的结晶焓（ΔH_c）随着PCMs中PEG质量分数的增加而降低，ΔH_c的绝对值最高可达137.81J/g。TG分析表明，当环境温度小于250℃时，PCMs的热稳定性较好。     

活性炭对PEG熔融和结晶性能的影响

采用物理吸附加熔融共混的方法制备PEG/活性炭复合相变材料,用差示扫描量热仪(DSC)研究活性炭加入量对PEG熔融和结晶性能的影响。结果表明:PEG/活性炭复合相变材料的熔融焓、结晶焓、熔融温度随着活性炭用量的增加而增加,结晶温度随活性炭用量的增加而减少;随着活性炭用量的增加,PEG/活性炭复合相变材料的热滞后度减小。     

PEG/CNFs相变储能材料非等温结晶动力学研究

通过溶液浇铸法制备了聚乙二醇/纤维素纳米微纤(PEG/CNFs)复合相变储能材料,采用差示扫描量热仪(DSC)研究了CNFs含量对该PEG/CNFs复合材料中PEG结晶行为的影响,并利用Jeziorny、Ozawa和Mo模型对DSC结果进行了非等温结晶动力学分析。结果表明:加入CNFs后,复合材料中PEG的半结晶时间(t1/2)与Avrami指数(n)下降,表明CNFs充当了PEG的成核剂;另外,CNFs含量的增加抑制了PEG晶体的生长,PEG的结晶焓(ΔHPEG)显著下降。     

聚乙二醇/石墨烯纳米片复合相变材料的制备及其性能研究

以聚乙二醇(PEG)作为相变工作物质,以具有优异导热性能的石墨烯纳米片(GNPs)作为导热填料,通过熔融共混法制备出一系列不同GNPs含量的PEG/GNPs复合相变材料。采用激光导热仪、差示扫描量热仪、扫描电子显微镜、X射线衍射仪、红外光谱仪等测试PEG/GNPs复合相变材料的导热性能、热物性、微观形貌、结晶性能及化学组成。结果表明,GNPs均匀分散于PEG基体中,形成能够加快热量传递的导热通路,复合材料体系的导热系数得以显著提高,而相变焓仅仅略微下降,当GNPs含量为2%时,复合材料体系的导热系数是PEG的249.7%,而相变焓损失率却仅为3.9%;PEG与GNPs二者间仅是物理吸附,并未发生化学反应,复合材料体系的结晶性能良好;PEG与GNPs复合相变材料的热响应速度更快,能源利用率因而更高。     

聚乙二醇/石墨烯纳米片复合相变材料的制备及其性能研究

以聚乙二醇(PEG)作为相变工作物质,以具有优异导热性能的石墨烯纳米片(GNPs)作为导热填料,通过熔融共混法制备出一系列不同GNPs含量的PEG/GNPs复合相变材料。采用激光导热仪、差示扫描量热仪、扫描电子显微镜、X射线衍射仪、红外光谱仪等测试PEG/GNPs复合相变材料的导热性能、热物性、微观形貌、结晶性能及化学组成。结果表明,GNPs均匀分散于PEG基体中,形成能够加快热量传递的导热通路,复合材料体系的导热系数得以显著提高,而相变焓仅仅略微下降,当GNPs含量为2%时,复合材料体系的导热系数是PEG的249.7%,而相变焓损失率却仅为3.9%;PEG与GNPs二者间仅是物理吸附,并未发生化学反应,复合材料体系的结晶性能良好;PEG与GNPs复合相变材料的热响应速度更快,能源利用率因而更高。     

铜纳米粒子导热增强固-液相变储能材料的性能

使用聚乙烯吡咯烷酮（PVP）和聚乙二醇（PEG）作为钝化剂对铜纳米颗粒进行原位包覆制备了PVP/PEG/Cu复合纳米粒子（CuNP），将其作为导热增强剂引入到PEG中制备了CuNP/PEG固-液相变储能材料（PCMs），并通过FTIR、XRD、DSC以及TGA等表征了CuNP/PEG固-液PCMs的结构及热性能。利用纳米粒子表面的PVP与PEG之间的氢键和空间位阻效应，以及PVP对铜核的保护作用，赋予了铜纳米粒子在PCMs中优异的分散稳定性。结果表明，CuNP的引入能够显著提高复合相变储能材料的导热能力，并能够作为晶核加速材料的结晶行为。当纳米粒子的质量分数为5%时，CuNP/PEG固-液PCMs的相变焓值为157.0 J/g，体系的储热速率、放热速率和结晶速率与纯PEG相比分别提高了34.09%、31.45%和53.33%。     

CNTs掺杂对EG/PEG定形相变材料性能的影响研究

以聚乙二醇(PEG)为相变材料,导热性与吸附性良好的膨胀石墨(EG)和碳纳米管(CNTs)为支撑材料,制备出CNTs/EG/PEG定形相变材料。分别采用恒温烘箱、差示扫描量热仪(DSC)、导热系数测定仪对CNTs/EG/PEG定形相变材料的定形特性、储热性能以及导热性能进行研究表征。实验结果表明,PEG含量越多的该定形相变材料的界面更加的均匀;随着EG和CNTs的含量增加,CNTs/EG/PEG复合材料的定形效果越来越好,熔融焓与结晶焓逐渐降低,导热系数逐渐增加。     

采用悬浮聚合法批量制备相变储能材料微胶囊

采用悬浮聚合法,利用自己设计的相变材料微胶囊(Micro PCMs)批量制备的生产设备合成了以正十八烷为囊芯,以苯乙烯马来酸酐-甲基丙烯酸甲酯共聚物P(MMA-co-SMA)为囊壁的相变储能微胶囊,熔融热焓值最高可达到150.12 J/g,结晶热焓值可达151.05 J/g,并通过扫描电子显微镜,差示扫描量热仪等对其性能进行了分析。讨论了乳化速度和乳化时间对批量制备相变储能微胶囊的热焓值和产量的影响。     

PEG/APS-SiO2/O-CNTs导热增强相变材料的制备及性能

以聚乙二醇(PEG)为相变材料,以3-氨丙基三乙氧基硅烷（APS）改性的二氧化硅(SiO2)为支撑材料,以氧化壁碳纳米管(O-CNTs)为导热增强材料,采用溶胶-凝胶法成功制备了PEG/APS-SiO2/O-CNTs导热增强型复合相变材料。通过FTIR、XRD、SEM、DSC等对材料的结构和热性能进行了表征。当PEG含量为82.0%时,复合相变材料仍然具有良好定型效果,熔化焓和结晶焓达到134.2 J/g、126.6 J/g,而且材料具有很好的储热稳定性,300次热循环后,其储热焓值仅下降3.3%。相比于纯PEG,添加了0.6%的O-CNTs的复合相变材料的导热增强率为28.1%, 达到0.41W/(m?K)。红外热成像结果表明,复合相变材料的储能效率明显提高。     

SLS用纳米羟基磷灰石/聚酰胺6复合粉体的制备及粉体性能分析

采用高温高压溶剂沉淀法制备出纳米羟基磷灰石/聚酰胺6(n-HAP/PA6)复合粉体。通过扫描电子显微镜(SEM)、示差扫描量热法(DSC)和X-射线衍射(XRD)对粉体的微观形貌、热性能和结构进行分析;通过对粉体粒径及分布、压缩度和休止角测试,讨论了粉体的流动性能。结果表明:制备出的粉体由蓬松多孔结构变为光滑致密的近球形颗粒;随着n-HAP含量的增加,n-HAP/PA6复合粉体的熔融焓逐渐降低,有助于降低选择性激光烧结(SLS)扫描功率;成功实现了对粉体粒径的控制,当n-HAP含量为10%时粒径达到29.68μm;压缩度和休止角的降低充分表明,复合粉体中n-HAP含量为10%时所制备的粉体流动性最好。     

聚酰胺6蓄热调温纤维的制备与表征

以聚乙二醇为储能调温介质,通过多孔纳米材料吸附制备了形态稳定的相变材料(PCMS),然后以聚酰胺6(PA6)为基体,采用熔融共混纺丝制备了蓄热调温PA6纤维。通过场发射扫描电子显微镜、差示扫描量热仪、热重分析仪、粉末X射线衍射仪表征了纤维的结构和性能。研究表明:熔纺PA6/PCMs纤维储能调温焓值达到19.01 J/g,预期可在航空服、军用作战服和民用服装等领域获得很好的应用。     

Phase change material with flexible crosslinking for thermal energy storage

The utilization of renewable energy through phase change materials (PCMs) is particularly attractive for the realization of sustainable society. Herein, a flexible but reliable solid–solid PCM was successfully synthesized by the integration of quadruple H-bonding crosslinks with polyethylene glycol (PEG)-based polyurethanes. The strong quadruple H-bonding from the dimerization of 2-ureido-4 [1H]-pyrimidinone (UPy) units could act as dynamic cross-links to maintain shape stability. PEG chains in flexible polymer network serve as phase change ingredients, affording thermal energy storage capacity. The physical crosslink density and phase change enthalpy can be adjusted. In contrast to chemical crosslinks, the physical crosslinks of UPy provide reprocessability of the prepared PCMs and show little hindrance on the crystallization of PEG chains. The chemical structure, phase transformation, crystallization, and thermal properties of prepared PCMs were characterized by fourier transform infrared spectroscopy, differential scanning calorimetry (DSC), X-ray diffraction, polarizing microscope, and thermogravimetric analysis. DSC analysis shows that the prepared PCM can store 101.9 J g⁻¹ when PCMs undergo phase change process. Moreover, the accelerated thermal cycling test and leakage test are also conducted to illustrate the thermal reliability and shape-stable properties. These PCMs that possess high phase change enthalpy and outstanding reprocessability are alternative for solar energy collection and waste heat recovery. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48497.     

化学法和共混法制备的PEG／CDA相变材料的性能比较：储热性能？…

通过IR、DSC和X-ray研究了用化学键联法和溶液共混法制备的聚乙二醇/二醋酸纤维素(PEG/CDA)型相变材料的相变热焓、相变温度和结晶度等物性,探索了两种材料的链结构与储热性能的关系.结果表明,对相同PEG含量的共混材料和化学改性材料而言,共混物的相变焓要大于化学改性材料的相变焓;但化学改性物是一种固固相变材料,而共混物不具有固固相变特性,只是一种形状稳定的固液相变材料.     

化学法和共混法制备的PEG/CDA相变材料的性能比较——储热性能与链结构的关系

通过IR、DSC和X -ray研究了用化学键联法和溶液共混法制备的聚乙二醇 /二醋酸纤维素 (PEG/CDA)型相变材料的相变热焓、相变温度和结晶度等物性 ,探索了两种材料的链结构与储热性能的关系。结果表明 ,对相同PEG含量的共混材料和化学改性材料而言 ,共混物的相变焓要大于化学改性材料的相变焓 ;但化学改性物是一种固固相变材料 ,而共混物不具有固固相变特性 ,只是一种形状稳定的固液相变材料     

电驱动PEG/EG复合相变材料的制备与性能

以聚乙二醇（PEG）为相变组分，膨胀石墨（EG）为支撑材料，采用真空浸渍的方法制备了PEG/EG电热转换相变储能材料。改变复合相变材料中EG的质量分数，探究其在电热转换与热能存储效率、定形效果、相变焓值、储放热速率等方面的作用。结果表明，EG不仅能够提高复合相变材料的导热性能，还赋予其导电性能。当EG质量分数为5%时，PEG/EG复合相变材料具有良好的电热转换性能，在外加电压为7 V时，其电热转换与热能存储效率达到80.6%。同时，复合相变材料表现出良好的定形效果、较高的相变焓值（152.2 J/g）和优异的导热性能，与纯PEG相比，其储热所用时间减少了73%，储放热速率大幅提高。因此，PEG/EG复合相变材料在电驱动热能存储系统和能量转换与存储等领域具有广阔的应用前景。     

Novel semi‐interpenetrating network structural phase change composites with high phase change enthalpy

High phase change enthalpy, controllable temperature, and stable shape can expand the application of phase change materials (PCMs) in energy storage. In this study, a series of novel form‐stable PCMs with high phase change enthalpy (169–195 J/g) and controllable temperature (45.3–61.4°C) were prepared. The PCMs exhibited a semi‐interpenetrating polymer network (semi‐IPN) structure resulting from the combination of polyethylene glycol (PEG) and a three‐dimensional (3‐D) network gel. The gel itself featured an inherent phase change characteristic and a 3‐D network structure. Thus, it improved the phase transition enthalpy of the materials and facilitated the formation of a semi‐IPN that endowed the materials with excellent form‐stable properties. In addition, the latent heat of the composites (169–195 J/g) is much higher than most of the previously reported composites using PEG as phase change component (68–132 J/g). © 2017 American Institute of Chemical Engineers AIChE J, 64: 688–696, 2018     

Solid–solid phase‐change materials based on hyperbranched polyurethane for thermal energy storage

A hyperbranched polyol (HBP) was synthesized with poly(ethylene glycol) (PEG) as the core molecule and 2,2‐bis(hydroxymethyl) propionic acid as the chain extender. Then, a series of hyperbranched polyurethane phase‐change materials (HP‐PCMs) with different crosslinking densities was synthesized with isophorone diisocyanate and HBP as a molecular skeleton and PEG 6000 as a phase‐change ingredient. ¹H‐NMR, gel permeation chromatography, and Fourier transform infrared spectroscopy confirmed the successful synthesis of the HBP and HP‐PCMs. The polarization optical microscopy and wide‐angle X‐ray diffraction results show that the HP‐PCM exhibited good crystallization properties, but the crystallinity was lower than that of PEG 6000. The analysis results from differential scanning calorimetry indicated that the HP‐PCMs were typical solid–solid phase‐change materials with suitable phase‐transition temperatures. In addition, HP‐PCM‐3, with an appropriate degree of hyperbranched structure, possessed the highest thermal transition enthalpy of 123.5 J/g. Moreover, thermal cycling testing and thermogravimetric analysis showed that the HP‐PCMs exhibited good thermal reliability and stability. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45014.     

Study on phase change characteristics of PEG/PAM coupling blend

A novel solid–solid phase change materials with polyethylene glycol (PEG) worked as phase change substance and polyacrylamide (PAM) as solid skeleton was synthesized by coupling blend. Their phase change behaviors and structure analysis was studied by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR), they had reversible solid–solid phase change properties. The result indicates that the PEG/PAM PCMs has great transition enthalpy and suitable phase transition temperature in the phase transition process. It can be considered as promising PCMs. Otherwise, their crystallization behavior were analyzed by polarization optical microscopy (POM), the crystalline degrees of these phase change materials were affected due to the intermolecular interaction and chemical bond. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010