聚氨酯松驰活化能的计算及其与微相分离结构的关系

本文以聚四氢呋喃（ＰＴＭＧ）、４，４－二苯基甲烷二异氰酸酯（ＭＤＩ）和１，４－丁二醇（ＢＤ）为原料，采用一步法合成聚氨酯样品，用ＤＤＶ－Ⅱ动态粘弹仪测定了样品的无能为力学图谱。首次建立一套利用动态力学图谱计算酯松弛活化能的方法，并用活化能大不定量地表征了聚氨酯的微相离结构。     

聚氨酯减震材料的动态力学分析

用动态力学分析（ＤＭＡ）仪对十余个聚氨酯微孔弹性体减震材料样品进行了测定,依据ＤＭＡ图谱对材料的耐热性耐寒性进行了评价。     

活性稀释剂对聚氨酯—环氧树脂互穿网络聚合物性能的影响

以聚氨酯(PU)和环氧树脂(FPOX)为两个组分,以丙烯酸羟乙酯(HEA)为活性稀释剂在紫外光照射下合成了互穿网络聚合物(IPN)的系列样品。应力应变和动态力学性能测量的结果表明,样品的力学强度随活性稀释剂的含量增加而降低,样品吸水率则是随稀释剂含量增加而增大。     

阻燃硬质聚氨酯泡沫制备及空气中热解特性

以可膨胀石墨(EG)和次磷酸铝(AHP)为阻燃剂,采用一步合成法制备了硬质聚氨酯泡沫/可膨胀石墨复合材料和硬质聚氨酯泡沫/次磷酸铝复合材料。采用热重分析(TG)法对阻燃型以及非阻燃型聚氨酯泡沫在10、20、30、40、50℃/min 5种不同升温速率下的热解过程及反应动力学进行了研究。实验结果表明,空气氛围下3种聚氨酯样品均存在2个主要失重阶段,样品初始分解温度由低到高为:RPUF/EG RPUF RPUF/AHP,其温度分别为187. 6、198. 83、203. 24℃。随着升温速率的增加,热解向高温区移动,主反应区逐渐增大,且最大热失重速率逐渐增大。加入可膨胀石墨与次磷酸铝均能提高样品成炭量。与此同时,运用Kissinger-Akahira-Sunose(KAS)和Ozawa-Flynn-Wall(OFW)方法求得,不同转化率时,3种聚氨酯样品活化能由大到小为:RPUF/AHP RPUF RPUF/EG,采用KAS方法求得的活化能分别为129. 36、151. 23、169. 45 k J/mol;采用OFW方法求得的活化能分别为123. 61、146. 92、166. 12k J/mol。     

抛光片用微孔聚氨酯弹性体的制备及性能表征

以混合聚醚和甲苯二异氰酸酯(TDI)为原料合成的预聚体作为A组分,以聚醚N220、3,3'-二氯-4,4'-二氨基二苯基甲烷(MOCA)、1,4-丁二醇(BDO)、水、辛酸亚锡、氧化铈粉末磨料等的混合物为B组分,将A、B均匀混合,通过半预聚体法合成了微孔聚氨酯弹性体。考察了不同磨料含量、BDO和MOCA比例及发泡剂水用量对微孔聚氨酯弹性体力学性能的影响,通过傅里叶变换红外光谱表征了微孔聚氨酯弹性体的微观结构,并通过动态力学分析(DMA)研究了微孔聚氨酯弹性体的动态力学性能。结果表明,磨料质量分数为14%、BDO和MOCA摩尔比为3∶7及水质量分数为0.6%时,制备的微孔聚氨酯弹性体力学性能较好,与进口样品接近;在环境温度低于50℃时,材料具有良好的抗形变能力和冲击强度;起始分解温度约为200℃,是一种性能良好的聚氨酯抛光材料。     

力学强度对自修复水性聚氨酯修复行为的影响

合成一系列基于双硫键动态交换的自修复水性聚氨酯,研究了硬段含量、交联剂用量对自修复水性聚氨酯力学性能的影响以及力学强度对其自修复行为的影响,并探讨了自修复行为对修复温度和时间的响应机制以及该类聚氨酯的自修复机理。结果表明：随着硬段含量和交联剂用量的提高,聚氨酯的力学强度提高;当水性聚氨酯的力学强度从 28 MPa提高至 40. 3 MPa,自修复性能呈现下降趋势,当力学强度达 40 MPa时,几乎不能修复（修复率 4%）;对力学强度 <30 MPa的样品,随着修复温度的提高和修复时间的延长,其自修复率提高,但对于高力学强度（ ≥40 MPa）的样品,即使升高温度和延长时间,其自修复率仍十分有限（修复率 13%）。自修复机理研究表明：体系内双硫键的动态交换和氢键的热可逆协同作用是其自修复的主要原因。     

用TGA技术分析阳离子水性聚氨酯的热行为

在不同升温速率条件下研究了阳离子水性聚氨酯在氮气中的热失重过程,用等转化率和主曲线法得出失重过程的活化能和动力学方程。实验得出阳离子水性聚氨酯的热失重温度范围为160~350℃;失重过程分两个阶段完成,第一阶段失重范围为0~55%,活化能为83.46kJ.mol-1,机理函数积分式为G(α)=[1-(1-α)1/2]2,第二阶段失重范围为60%~100%,活化能为95.61kJ.mol-1,机理函数积分式为G(α)=α+(1-α)ln(1-α)。在失重为55%~60%之间两步重叠。     

低游离甲苯二异氰酸酯(TDI)的聚氨酯固化剂合成研究

使用催化聚合法合成了无害、低游离甲苯二异氰酸酯(TDI)的聚氨酯固化剂;并且通过正交试验确定了催化过程的最优反应条件。测试结果表明:W2030-低分子醇混合体系加入反应体系后,明显降低了预聚体中的游离TDI含量。在最优条件下合成的固化剂中的TDI残留量均低于0.5%;同时还通过动力学计算了催化聚合体系的活化能,并与TDI-TMP反应体系活化能作了比较,得出的结果表明TDI-W2030-低分子醇混合体系相对于TMP-TDI反应体系有较低的活化能,有利于制备低游离TDI的固化剂。     

聚氨酯基约束阻尼复合材料的制备及性能研究

研究了以聚醚多元醇、甲苯二异氰酸酯以及正丁基醇为原料,通过预聚体法合成聚氨酯预聚物,将其与功能填料混合制备聚氨酯基阻尼层材料。利用动态力学热分析仪(DMA)对阻尼层材料样品热性能进行了研究。将该阻尼材料与纤维复合铝箔复合制备了复合约束型阻尼材料。利用模态测试对其进行放大样品阻尼比测试。实验结果表明,复合约束阻尼材料的阻尼比达到20.03,较市售阻尼材料阻尼比(8.64)提高近一倍。     

蓖麻油聚氨酯基网状聚合物的动态力学性质

研究了蓖麻油聚氨酯基AB型交联聚合物(ABCP)及同步法合成互穿聚合物网络(IPN)的动态力学谱。ABCP的两组分近似互容,在动态力学谱上呈现出单一T_g松弛,用透射电子显微镜观察,聚氨酯相区尺寸小于 2 nm;而其化学组成相同的 IPN则呈现出两相结构,其动态力学谱上有两个 T_g松弛,两组分间虽有链段互穿,但其相容性仍次于 ABCP。     

表面改性芳纶复合材料的界面粘结与界面断裂韧性

本文以表面改性芳纶和改性ＢＭＩ型树脂组成复合材料体系，研究芳纶表面改性其复合材料界面粘结与界面断裂韧性的影响。     

独山子1号乙烯装置节能降耗及保障措施

"十一·五"期间,独山子1号乙烯装置通过优化原料结构、采取"四新"技术、加强工艺管理、关键设备特护、强化现场管理等一系列有效措施,不仅保证了能耗指标的顺利完成,而且保持了能耗指标的先进性     

THE DEVELOPMENT AND IMPROVEMENT OF ENERGY EFFICIENT REFRIGERATORS

The growing concerns over global warming due to greenhouse gas emissions have pushed the appliance industry to further improve energy efficiency of its products. Refrigerator-freezers (RF), as one of the major home appliances, consume about one-fifth of the electricity in a household, and its life expectancy could be as long as 10–15 years. In response to future stricter regulations, several design options were considered for improving the energy efficiency of a conventionally designed domestic RF. The options, such as insulation improvements obtained by using vacuum insulation panels (VIPs), energy saving defrost control, and high-efficiency compressors were examined in a prototype RF

The energy consumption of the original 1997 production refrigerator-freezer was selected as the baseline in order to compare the measured energy savings of each option and the combined options on the prototype refrigerator-freezer. This study has reached a goal to develop a prototype that has an energy consumption rate of 20% less than the baseline model.     

Long‐term thermal conductivity of cyclopentane–water blown rigid polyurethane foams reinforced with different types of fillers

An understanding of the long‐term thermal conductivity of rigid polyurethane (RPU) foams presents great interest in the building field considering the conservation of energy efficiency. In this study, the effect of different types of particles (talc, diatomaceous earth and non‐porous silica) on the thermal conductivity of RPU foams blown with cyclopentane and water as blowing agents was investigated during 3 years of aging. The characterization of the cellular structure shows how the addition of particles causes a cell size reduction of the foams, and consequently an enhancement of the thermal properties just after production. However, this initial reduction is not maintained, because each foam shows a different thermal conductivity evolution with time. We have found, for the first time, a relationship between the slope of the thermal conductivity versus time at the first measurements and the internal temperature reached during the foaming process. The evolution of the RPU foams in which higher internal temperatures were reached is more pronounced than in those RPU foams where lower foaming temperatures were observed. This effect is related to the kinetics of the diffusion of the gas occluded inside the cells and imposes a new criterion for the selection of particles to reduce the thermal conductivity of RPU foams; these additives should ideally decrease the temperature reached during the foaming process. Moreover, the effect of aging on the thermal conductivity is explained by using theoretical models. © 2019 Society of Chemical Industry     

THE DEVELOPMENT AND IMPROVEMENT OF ENERGY EFFICIENT REFRIGERATORS

The growing concerns over global warming due to greenhouse gas emissions have pushed the appliance industry to further improve energy efficiency of its products. Refrigerator-freezers (RF), as one of the major home appliances, consume about one-fifth of the electricity in a household, and its life expectancy could be as long as 10-15 years. In response to future stricter regulations, several design options were considered for improving the energy efficiency of a conventionally designed domestic RF. The options, such as insulation improvements obtained by using vacuum insulation panels (VIPs), energy saving defrost control, and high-efficiency compressors were examined in a prototype RF

The energy consumption of the original 1997 production refrigerator-freezer was selected as the baseline in order to compare the measured energy savings of each option and the combined options on the prototype refrigerator-freezer. This study has reached a goal to develop a prototype that has an energy consumption rate of 20% less than the baseline model.     

太阳能在海水淡化产业中的应用与研究进展

太阳能蒸馏技术与太阳能反渗透技术是太阳能在海水淡化产业中主要的应用形式.从本质上讲,前者是利用太阳能的光热转换,而后者是利用太阳能的光电转换.文章从上述两个方面出发,综述了近几个世纪以来太阳能在海水淡化产业中的应用与研究进展,并对该产业下一步的发展进行了初步展望.     

高锰酸钾蒸发工艺改进和节能降耗措施

由于旧工艺和设备的不合理性,造成蒸发生产能力低,蒸汽和水的消耗高,碱损大。本文列举了旧工艺存在的问题,阐述了改进后的新工艺特点,并提出了几点节能降耗的措施。     

活性污泥投加低剂量粉末活性炭降低锦纶废水氨氮的应用研究

进行了一段单级低剂量粉末活性炭技术(LD-PACT)处理系统(即碳氧化、硝化和反硝化混合污泥相)生产性应用试验。结果表明,LD-PACT工艺出水CODcr比活性污泥法要低,NH_3-N去除效果明显,同时污泥沉降性能有所改善,证明了用这一系统进行生物脱氧是成功的。本工艺不仅适用于新建工程,也可应用于现有设施的挖潜改造,是值得推广的一种生物脱氧好方法。     

扬子乙烯能耗统计及节能措施

介绍了扬子乙烯能耗统计范围和统计方法,并针对扬子乙烯装置能耗水平现状,结合目前国内其它乙烯装置的新技术,分析找出差距,并对降低装置能耗提出了相应措施。     

Melamine amino trimethylene phosphate as a novel flame retardant for rigid polyurethane foams with improved flame retardant,mechanical and thermal properties

Melamine amino trimethylene phosphate (MATMP) as a novel nitrogen‐phosphorus flame retardant, was synthesized by the reaction of melamine with amino trimethylene phosphonic acid (ATMP) in aqueous solution. The structure of MATMP was characterized by Fourier transform infrared spectroscopy, solid state 31 P nuclear magnetic resonance, and thermogravimetric analysis. Rigid polyurethane (RPU) foams were prepared by one‐shot and free‐rise method, using MATMP as a flame retardant. The flame retardant, mechanical and thermal properties of MATMP in RPU foams were studied. It is found that the RPU foam containing 15 wt % MATMP (sample RPUMA‐15) can pass the UL‐94 V0 test with a limiting oxygen index of 25.5%. The cone calorimeter test results show that the peak heat release rate of RPUMA‐15 is reduced about 34% compared with that of untreated RPU foam. SEM results indicate that the RPU foams with MATMP can form the good and compact char during burning which provides better flame retardancy. The compressive strength of the RPU foams filled with MATMP first increases and then slightly decreases with an increase in the MATMP content comparing with that of untreated RPU foam. Moreover, thermal conductivities of the MATMP filled RPU foams are about 0.03 W/m K. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45234.