2,4,6—三溴丙烯酸苯酯的合成

研究了以２,４,６－三溴苯酚、丙烯酸、三氯化磷为基本原料,通过分步法合成２,４,６－三溴丙烯酸苯酯的方法,并通过正交实验和单因素优化找到了适宜的工艺条件。对所得产品进行了分析测试,确定了产品是目的产品。并给出了产品的熔点、折光率、溴含量、分子量、分子结构及纯度等的测定值。     

丙烯酸聚乙二醇-400单酯的制备与表征

以对甲苯磺酸为催化剂,对苯二酚为阻聚剂,甲苯为带水剂,聚乙二醇-400(PEG400)和丙烯酸为原料,通过酯化反应合成了丙烯酸聚乙二醇-400单酯并进行了表征.研究了酯化反应的影响因素,确定了最佳反应条件:n(丙烯酸):n(聚乙二醇)=1.2:1,对甲苯磺酸质量分数为1%(以醇酸总质量计),对苯二酚质量分数为0.5%(以醇酸总质量计),反应温度为115℃,反应时间为6 h,酯化率可达到85.3%.     

丙烯酸聚乙二醇单酯的合成研究

以聚乙二醇-200与丙烯酸直接缩合反应,在不加有毒带水剂的条件下合成了丙烯酸聚乙二醇单酯。探讨影响缩合反应酯化率的因素,确定酯化反应的最佳条件：丙烯酸与PEG200的摩尔比为1.2∶1.0,反应温度是110-140℃,阻聚剂对苯二酚为0.6%（以醇酸总质量计）,反应时间为6 h,催化剂对甲苯磺酸为1.0%（以醇酸总质量计）,产率达89.4%。     

丙烯酸氢化松香醇酯的合成和表征

将丙烯酰氯和氢化松香醇按n(羟基)∶n(酰氯)=1∶1进行酯化反应合成了丙烯酸氢化松香醇酯,分别采用FTIR、GC-MS、13CNMR和DSC对其结构和性能进行了表征。结果表明,丙烯酸氢化松香醇酯主要由丙烯酸四氢松香酯、丙烯酸二氢松香酯、丙烯酸去氢松香酯和少量氢化松香甲酯组成,前3个组分质量分数总和为80.45%,所制备的丙烯酸氢化松香醇酯在引发剂存在下可以发生聚合反应,聚合物玻璃化温度为-28.92℃,可作为共聚物的内增塑剂。     

相转移催化法制备丙烯酸烯丙酯

以丙烯酸钠与氯丙烯(ALC)为原料,在相转移催化剂存在下合成出丙烯酸烯丙酯(ALA)粗产品,经离心、干燥、蒸馏等纯化手段得ALA产品。最佳反应条件为:以四丁基溴化铵为相转移催化剂,用量为反应物物质的量的4%,VALC∶V水=1∶1,在40℃下反应1.75 h,ALA产率达94%以上,纯度达98%以上。     

聚双甲基丙烯酸聚乙二醇酯固-固相变储能材料的制备

制备了以聚甲基丙烯酸为骨架、聚乙二醇(PEG)为工作物质的新型高分子固-固相变储能材料。对PEG和几种不同的相变材料分别进行DSC测试,对PEG分子量为4000的相变材料进行非等温DSC测试。结果表明,与纯PEG相比,相变材料的相转变温度降低12.3℃,相变焓降低45 J/g。随着聚乙二醇分子量由2000依次增加为4000,6000,10000,相变材料的相转变温度分别为44.8,52.9,63.8和74.3℃,相变焓分别为142.9,203.2,190.1,231.4 J/g,均有增加的趋势。随着升温速率增加,PEG分子量为4000的PCM的相变温度依次升高,分别为47.4,50.0和53.1℃。     

固体超强酸催化合成丙烯酸聚乙二醇单酯

以聚乙二醇单甲醚(600)与丙烯酸直接缩合反应,在固体超强酸 SO2-4/ZrO2 催化下合成丙烯酸聚乙二醇单酯. 探讨影响缩合反应酯化率的因素, 确定酯化反应的最佳条件: 丙烯酸与PEGME-600的摩尔比为1.2∶1.0, 阻聚剂对苯二酚为0.6%(以单体总质量计), 反应时间为4 h, 催化剂为0.5%(以醇酸总质量计),产率达88.1%.     

丙烯酸纤维素的合成与表征

以丙烯酰氯为酰化剂与纤维素的(5%-10%)LiCl/DMAc的均相溶液酰化反应,制备丙烯酸纤维素.采用FTIR、元素分析对反应产物进行了结构表征和取代度的测定.探讨反应温度、反应时间、酰化剂用量以及纤维素浓度对反应产物取代度的影响.得到了丙烯酰氯对纤维素较佳酰化反应条件:反应温度为50℃,反应时间为3.5h,丙烯酰氯官能团与纤维素羟基的物质的量之比为3.35,纤维素浓度为1.95%.     

二甲基丙烯酸聚乙二醇酯的RAFT交联聚合行为

采用差示扫描量热(DSC)和动态力学分析(DMA)方法研究二甲基丙烯酸聚乙二醇酯(PEGDMA)的可逆加成-断裂链转移(RAFT)自由基交联聚合,探索了交联单体双键间链段长度和链柔性对RAFT交联聚合动力学及其交联结构的影响.实验发现,随着双键间乙二醇单元数由4增加到9,聚合速率加快,当乙二醇单元数由9增加到14,聚合速率不增反降,这种行为是交联网络密度减小后增长自由基浓度下降和悬挂双键反应活性增加共同作用的结果;双键间链段柔性的增加使RAFT交联聚合速率加快:随双键间链段长度增加,交联网络密度和玻璃化转变温度降低,交联网络的均匀性得到改善.     

聚乙二醇对甲苯磺酸酯的制备

标题化合物是制备多种末端功能化聚乙二醇衍生物的重要中间体。交流不同分子量的聚乙二醇和聚乙二醇单甲醚与对甲苯磺酰氯进行酯化的反应条件及提纯方法,制备出3个双(对甲苯磺酸)聚乙二醇酯,收率65%~80%;2个单对甲苯磺酸聚乙二醇单甲醚酯,收率55%~61%;其结构经1HNMR表征。     

聚乙二醇/二氧化硅定形相变材料的制备

采用多孔二氧化硅（SiO₂）、聚乙二醇(PEG)等研究一种定形无机 有机复合相变材料的制备方法,并加入适当的促进剂和改性剂对复合材料进行了改性。利用多孔二氧化硅具有良好的吸附性能特点,将聚乙二醇相变材料吸附在二氧化硅微孔结构内,在毛细管力和表面张力的作用下,聚乙二醇在发生固液相变的时候很难从二氧化硅的微孔结构内渗透出来,从而解决了聚乙二醇在蓄热技术中应用时的液体流动问题。同时对相变材料进行了热性能分析,实验证明该复合相变材料具有形状稳定,导热率高,储热能力大等特点。     

Synthesis and characterization of polyethylene glycol acrylate crosslinking copolymer as solid–solid phase change materials

A kind of crosslinking copolymer as solid–solid phase change material (PCM) is synthesized by copolymerization. The scope of PCM applications is often severely limited by their heat stablility and phase transition state. The solid–solid phase change materials we obtained retain basic state during phase change transitions. The crosslinking polymer is heat stable under 300° and the latent heat of crystalline and latent heat of melting is on the average of 120 J/g and 140J/g, respectively. The property of thermal stability and heat storaged is related to crosslinking density of the gel. The property of thermal stability and high latent heat may expand the scope of PCMs applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 39755.     

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。     

Poly(polyethylene glycol methyl ether methacrylate) as novel solid-solid phase change material for thermal energy storage

Poly(polyethylene glycol methyl ether methacrylate) as novel solid–solid phase change materials (PCMs) for thermal energy storage was prepared via the facile bulk polymerization of polyethylene glycol methyl ether methacrylate and was characterized by Fourier transform infrared, ¹³C-NMR, X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis measurements. Based on the results, it is indicated that the poly (polyethylene glycol methyl ether methacrylate) as novel PCM showed solid–solid properties with suitable transition temperature, high transition enthalpy, and good thermal stability, which was apt to crystallize due to the flexibility of long polyether side chain. This novel PCMs have advantages for the potential application in energy storage. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Adjustable thermal property of polyethylene glycol/diatomite shape‐stabilized composite phase change material

The work involves the fabrication, characterization, and thermal properties of polyethylene glycol (PEG)/diatomite powder (DP), which can be used as a novel shape‐stabilized composite phase change material (CPCM). The maximum load of PEG in DP can reach 55% while PEG melts during solid–liquid phase transformation. Differential scanning calorimeter results indicated that the melting temperature of the new CPCMs could be adjusted from 34 to 59°C and that the solidifying temperature could be adjusted from 27 to 44°C. Corresponding latent heats of the melting and solidifying processes were 77.27–106.5 J/g and 72.07–94.93 J/g, respectively. Scanning electronic microscope, Fourier transform infrared spectroscopy, and X‐ray diffraction results indicated that PEG was well dispersed in diatomite pores and no chemical changes took place during thermal cyclic test. Thermo‐gravimetric analysis indicated that the CPCMs had good thermal and chemical stability and reliability when diatomite was immersed into melting PEG at 75°C for 90 min. Thermal conductivity of the CPCMs increased from 0.36 to 0.71 W/mK after adding 10 wt% expanded graphite (EG). POLYM. COMPOS., 37:854–860, 2016. © 2014 Society of Plastics Engineers     

Performance evaluation of polymer/clay nanocomposite thermal protection systems based on polyethylene glycol phase change material

Phase change materials (PCMs) are substances with a high heat of fusion which, through melting and solidifying at specified temperatures, are capable of storing or releasing a large amount of thermal energy. This phenomenon can be utilized in designing the heat protective materials as well as in the thermal energy storage systems. In this work, effects of polyethylene glycol (PEG) as PCM and montmorillonite nanoclay, as a thermal property modifier in epoxy resin on the thermal protection performance of nanocomposites were studied. A special performance evaluation test was designed to study the top surface temperature behavior of prepared samples under back surface heating. Results indicated that increasing PCM content improved thermal protection performance, but lower thermal diffusivity was found for the sample containing 60 wt% of PEG, with a 31 % decrease in top surface temperature. These results show that increasing of top surface temperature of samples containing PCM was very slow when compared with the neat epoxy sample. A top surface temperature behavior of these samples shows a plateau in melting region of PCM which makes a delay time in temperature increment compared with that of the neat epoxy sample. Moreover, heat protection performances of low filled nanocomposite blends, i.e., nanocomposite blends with 5 and 7 wt% of clay in PEG have been improved about 10 % in comparison with EP/PEG60 blend.     

聚乙二醇二元体系的相变特性研究

采用步冷曲线法和差示扫描量热法考察不同分子量聚乙二醇(PEG)及其二元相变体系的相变特性。结果表明,PEG分子质量和组分质量比对相变体系的相变温度和相变潜热有较大的影响,随着PEG分子量的增大,相变起始温度和相变峰温均呈升高趋势,相变潜热先升后降;二元相变体系PEG2000/PEG4000不同质量比步冷曲线均有明显的温度平台,结晶温度38.4⁴3.2℃,且变化趋势相近;DSC分析PEG2000/PEG4000相变温度和相变潜热均处于PEG2000和PEG4000单一组分范围之间,不同质量比时升温过程中双组分单独作用出现双峰,降温过程中双组分协同作用出现单峰。因此,将不同分子量PEG按一定质量比例共混可实现温度调控的相变材料。     

聚乙二醇二元体系的相变特性研究

采用步冷曲线法和差示扫描量热法考察不同分子量聚乙二醇(PEG)及其二元相变体系的相变特性。结果表明,PEG分子质量和组分质量比对相变体系的相变温度和相变潜热有较大的影响,随着PEG分子量的增大,相变起始温度和相变峰温均呈升高趋势,相变潜热先升后降;二元相变体系PEG2000/PEG4000不同质量比步冷曲线均有明显的温度平台,结晶温度38.4~43.2℃,且变化趋势相近;DSC分析PEG2000/PEG4000相变温度和相变潜热均处于PEG2000和PEG4000单一组分范围之间,不同质量比时升温过程中双组分单独作用出现双峰,降温过程中双组分协同作用出现单峰。因此,将不同分子量PEG按一定质量比例共混可实现温度调控的相变材料。     

Shape-stable phenolic/polyethylene glycol phase change material: kinetics study and improvements in thermal properties of nanocomposites

Storage, transformation, and absorption of energy play effective roles in application and performance of heat and thermal energy beneficiary. Phase change materials (PCMs) are substances with high heat of fusion which can be utilized to design thermal protective and thermal energy storage systems. However, PCM leakage in phase changing process is a well-known disadvantage of the PCM containing systems. One of the approaches to avoid PCM leakage is to prepare shape-stabilized PCM in polymeric composites. In this study, polyethylene glycol (PEG), as a PCM, was shape-stabilized with low leakage in the novolac colloidal structure with no solvent and through a sol–gel in situ polymerization process. Supercooling is a negative associate phenomenon in these systems, which may occur due to the low rate of nucleation and nucleation growth. Nanoclay was used to avoid supercooling of PEG. PEG supercooling significantly decreased when 2.5 wt% of nanoclay was incorporated. This is due to the role of nanoclay particles as the crystal nuclei. The sol–gel polymerization kinetics of novolac resin in the presence of nanoclay and molten PEG was also studied using the Kamal–Sourour model. Results showed that 85 wt% of PEG was preserved with leakage less than 3.5 wt% by shape stabilization encapsulated with colloidal structure of the phenolic resin. Nanoclay improved the thermal properties of the system and reduced the supercooling about 20%. Moreover, based on Kamal–Sourour model, polymerization kinetics could suggest a lower novolac curing rate in the presence of molten PEG and nanoclay.