二胺扩链剂对RIM聚氨酯－脲弹性体的结构与性能的影响

采用实验室小型ＲＩＭ机制备了一组不同芳香二胺扩链的嵌段聚氨酯－脲（ＰＵＵ）弹性体，借助于ＩＲ、ＤＳＣ、ＤＭＴＡ、ＳＥＭ以及拉伸试验等测试手段对其结构与性能进行了研究。     

RIM聚氨酯脲的微相分离的DSC研究──硬段结构和含量对微相分离的影响

用ＤＳＣ法研究了二乙基甲苯二胺和４，４＇－氨基二苯基甲烷（ＭＤＡ）扩链的硬段含量为２７％～６０％的两个系列的反应注射成型（ＲＩＭ）聚氨酯脲（ＰＵＵ）弹性体的微相分离。聚合反应动力学对ＲＩＭＰＵＵ的微相分离有很大影响．随着硬段浓度的增加微相分离程度下降，ＭＤＡ扩链系列聚合总反应速度快，微相分离驱动力弱，在硬段生成反应比软段生成反应快的条件下，该系列的微相分离程度较低。聚合总反应快，且硬段间氢键化作用很强的性质造成ＲＩＭＰＵＵ非平衡的形态。聚合总反应速度的增加相当于微相分离驱动力的下降。     

RIM聚氨酯脲的微相分离的DSC研究—硬段结构和含量对微相…

用ＤＳＣ法研究了二乙基甲苯二胺和４，４＇－二氨基二苯基甲烷扩链的硬段含量为２７％－６０％的两个系列的反应注射成型聚氨酯脲弹性体的微相分离，聚合反应动力学对ＲＩＭ ＰＵＵ的微相分离有很大影响，随着硬段浓度的增加微相分离程度下降，ＭＤＡ扩链系列聚合总反应速度快，微相分离驱动力弱，在硬段生成反应比软段生成反应快的条件下，该系列的微相分离程度较低，聚合总反应快，且硬段间氢键化作用很强的性质造成ＲＩＭ ＰＵ     

STUDIES OF POLYMER IMMOBILIZED Pd－Cu CLUSTER CATALYSTS PREPARED BY METAL ATOM SYNTHESIS（MVS）

ＳＴＵＤＩＥＳＯＦＰＯＬＹＭＥＲＩＭＭＯＢＩＬＩＺＥＤＰｄ－ＣｕＣＬＵＳＴＥＲＣＡＴＡＬＹＳＴＳＰＲＥＰＡＲＥＤＢＹＭＥＴＡＬＡＴＯＭＳＹＮＴＨＥＳＩＳ（ＭＶＳ）ＳｈｉＨｕａｗｕ；ＣｈａｎｇＹｉｎｇＺＨＵ；ＪｉＬｉａｎｇＺＨＵａｎｄＸｉＳｈｅｎｇＳＨ...     

PREPARATION AND CHARACTERIZATON OF MICROPOROUS CATALYTIC MATERIALS WITH NARROW PORE DISTRIBUTION AND HIGHLY DISPERSED PALLADIUM

ＰＲＥＰＡＲＡＴＩＯＮＡＮＤＣＨＡＲＡＣＴＥＲＩＺＡＴＯＮＯＦＭＩＣＲＯＰＯＲＯＵＳＣＡＴＡＬＹＴＩＣＭＡＴＥＲＩＡＬＳＷＩＴＨＮＡＲＲＯＷＰＯＲＥＤＩＳＴＲＩＢＵＴＩＯＮＡＮＤＨＩＧＨＬＹＤＩＳＰＥＲＳＥＤＰＡＬＬＡＤＩＵＭ￥ＡｎＷｕＬｉ；ＧｕｏＸ...     

MICROCALORIMETRIC STUDIES OF SURFACE ACID/BASE PROPERTIES OF REDUCED IRON／MAGNESIUM CATALYSTS

ＭＩＣＲＯＣＡＬＯＲＩＭＥＴＲＩＣＳＴＵＤＩＥＳＯＦＳＵＲＦＡＣＥＡＣＩＤ／ＢＡＳＥＰＲＯＰＥＲＴＩＥＳＯＦＲＥＤＵＣＥＤＩＲＯＮ／ＭＡＧＮＥＳＩＵＭＣＡＴＡＬＹＳＴＳ＊ＴｕＭａｉ，ＳｈｅｎＪｉａｎｙｉ＊＊，ＣｈｅｎＹｉ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈ...     

STUDY ON IMMOBILIZED PORCINE PANCREATIC LIPASE CATALYZING TRANSESTERIFICATION BETWEEN METHYL－BUTYRATE AND 1－BUTANOL IN NONAQUEOUS SYSTEMS

ＳＴＵＤＹＯＮＩＭＭＯＢＩＬＩＺＥＤＰＯＲＣＩＮＥＰＡＮＣＲＥＡＴＩＣＬＩＰＡＳＥＣＡＴＡＬＹＺＩＮＧＴＲＡＮＳＥＳＴＥＲＩＦＩＣＡＴＩＯＮＢＥＴＷＥＥＮＭＥＴＨＹＬ－ＢＵＴＹＲＡＴＥＡＮＤ１－ＢＵＴＡＮＯＬＩＮＮＯＮＡＱＵＥＯＵＳＳＹＳＴＥＭＳＸｉ...     

STUDY ON COMPOSITION AND STABILITY CONSTANTS OF THE INCLUSION COMPOUNDS OF β－CYCLODEXTRIN WITH DIPHENYL AND ITS DERIVATIVES BY NMR

ＳＴＵＤＹＯＮＣＯＭＰＯＳＩＴＩＯＮＡＮＤＳＴＡＢＩＬＩＴＹＣＯＮＳＴＡＮＴＳＯＦＴＨＥＩＮＣＬＵＳＩＯＮＣＯＭＰＯＵＮＤＳＯＦβ－ＣＹＣＬＯＤＥＸＴＲＩＮＷＩＴＨＤＩＰＨＥＮＹＬＡＮＤＩＴＳＤＥＲＩＶＡＴＩＶＥＳＢＹＮＭＲ￥ＬｅＸｉｎＳＯＮＧ；Ｘｉ...     

GRAFT COPOLYMERIZATION OF BUTYL ACRYLATE ONTO CASEIN INITIA BY POTASSIUM DIPERIODATOARGENTATE

ＧＲＡＦＴＣＯＰＯＬＹＭＥＲＩＺＡＴＩＯＮＯＦＢＵＴＹＬＡＣＲＹＬＡＴＥＯＮＴＯＣＡＳＥＩＮＩＮＩＴＩＡＢＹＰＯＴＡＳＳＩＵＭＤＩＰＥＲＩＯＤＡＴＯＡＲＧＥＮＴＡＴＥ￥ＷｅｉＨｏｎｇＬＩＵ；ＹｉｕｇＨａｔＬＩＵ；ＹａＪｕａｎＳＨＡＮＧ，ＭｉｎｇＪｕｎ...     

SYNTHESIS AND SPECTRA STUDIES OF TRANSITION METAL COMPLEXES DERIVED FROM 2， 4－DINITROPHENYL HYDRAZINE

ＳＹＮＴＨＥＳＩＳ　ＡＮＤ　ＳＰＥＣＴＲＡ　ＳＴＵＤＩＥＳ　ＯＦ　ＴＲＡＮＳＩＴＩＯＮ　ＭＥＴＡＬ　ＣＯＭＰＬＥＸＥＳ　ＤＥＲＩＶＥＤ　ＦＲＯＭ　２，　４－ＤＩＮＩＴＲＯＰＨＥＮＹＬ　ＨＹＤＲＡＺＩＮＥＳＹＮＴＨＥＳＩＳＡＮＤＳＰＥＣＴＲＡＳＴＵＤＩ...     

CAMDA扩链聚氨酯脲的硬段对形态与性能的影响

由红外光谱、核磁共振及质谱分析证实了所合成的3-氯-3’-甲氧基-4,4’-二氨基二苯基甲烷(CAMDA)具有预期的化学结构.用RIM方法制成的CAMDA基聚氨酯脲(PUU)性能接近于DETDA扩链的PUU.用快速手工浇注法制备了一系列由CAMDA扩链的不同硬段含量的PUU样品.采用DSC、SEM观察了硬段含量由10％增加到45％PUU形态的变化,并测量了力学性能.实验结果表明:随着硬段含量增加,PUU的形态由平行间隔的软、硬链段富集区经相互穿叉的软、硬段富集区,进一步聚集成硬链段富集球状超级结构,强度亦相应提高.     

不同硬段含量溶液聚合和RIM嵌段聚脲热性质和动态力学性质的研究

用溶液聚合法和RIM制备了软段为胺端基聚环氧丙烷,硬段为4,4′-二苯甲烷二异氰酸酯(含量为30％,50％,70％)经二乙基甲苯二胺扩链的热塑性嵌段聚脲。用动态力学温度谱(DMS)和示差扫描量热计法(DSC)对比研究了这些聚脲的性质。结果表明,溶液聚脲比RIM聚脲的枢分离情况好。DMS和DSC均未观察到聚脲中硬段的玻璃化转变。     

FTIR研究交联聚氨酯脲弹性体的结构对动态性能的影响

用傅立叶变换红外光谱法(FTIR)研究交换PUU的结构指出,化学交联键的存在使得氢键化的NH吸收位置向高波数方向移动,同时羰基区内完全有序的氢键化脲羰基(1642cm-1)吸收较弱,完全有序的氨酯羰基(1693cm-1)吸收谱带观察不到.随着温度的升高,氢键化的NH吸收强度逐渐减弱,谱带吸收位置向高波数方向移动.FTIR结果揭示了交联PUU弹性体内部微相混合程度较线性PUU的高,交联PUU弹性体的回弹性在同温度下小于线性PUU的回弹性,随温度的升高,交联PUU弹性体极性键间的氢键化作用较易破坏,分子的柔顺性增加较快,交联PUU的回弹性增加幅度较大.交联密度越大,回弹性越小,压缩生热越大.硬段含量越高,材料的生热现象越严重.扩链剂的用量增加,对交联PUU的回弹性和压缩生热影响不大,但它显著地改善了PUU的疲劳性能.     

具有明确硬段结构的水性聚氨酯脲的研究

通过逐步反应由4,4′-二苯基甲烷二异氰酸酯、2,2-二羟甲基丙酸和1,4-丁二醇,合成了结构明确的硬段模型化合物.通过13C NMR对其序列结构进行了表征,并通过FTIR、DSC和WAXD对其形态结构进行了研究.进一步制备了具有这类规整结构硬段的水性聚氨酯脲,初步考察了水分散液及其成膜后的性能.实验结果表明,这类聚氨酯脲水分散液的粒径小于110nm,在室温下贮存期大于一年,成膜后具有优异的耐水性能以及表面疏水性能.     

Evidences of phase separation in moisture‐cured poly(urethane urea)s by means of temperature modulated differential scanning calorimetry

The degree of phase separation in several moisture‐cured poly(urethane urea)s (PUUs) was studied by FTIR spectroscopy, wide angle X‐ray diffraction (WAXD), and temperature‐modulated differential scanning calorimetry (TMDSC). This latter technique was shown to be particularly useful in analysing the degree of phase separation in PUU polymers. Both phase mixing and phase segregation coexisted in the PUUs and the degree of phase separation increased as the urea hard segment (HS) content in the PUU increased. The maximum solubility of urea HSs into the polyol soft segments (SSs) was achieved for 50 wt % urea HS content in diol‐based PUUs, whereas for triol‐based PUUs the highest solubility between HS and SS was reached for lower urea HS amount. Finally, the higher the urea HS content the higher the extent of phase separation in the PUU. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 3034–3045, 2007     

Poly(urea)urethanes based on amorphous quaternizable hard segments and a crystalline polyol derived from castor oil

A set of poly(urea)urethanes (PUU), with different contents of amorphous hard segment and castor oil-derived crystalline polyol as soft segment, was prepared combining bulk and solution polymerizations. It is shown that both the soft segment crystallinity and hard segment glassy nature control the stiffness of the materials and that phase mixing at intermediate hard segment compositions produces softer materials. Upon yielding, PUU developed large plasticity associated to the nature of soft segments. At longer strains, PUU presented strain-induced crystallization related both to soft segments alignment and crystallization, leading to strong and tough materials, especially with high hard segment content compositions. Despite the hydrophobicity of the soft segments, the PUU with 65 wt% hard segment content was dispersable in water after quaternization with acetic acid. The high amount of urea groups in this quaternized PUU makes one think of these types of polymers as promising water soluble environmentally friendly strong adhesives, coatings, or water soluble polymeric electrolites.     

Preparation and Pervaporation Performances of PEA‐based Polyurethaneurea and Polyurethaneimide Membranes to Benzene/Cyclohexane Mixture

Pervaporation is promising in the separation of benzene/cyclohexane mixture for the petrochemical industry. Two kinds of pervaporation membrane materials, including PEA‐based polyurethaneurea (PUU) and polyurethaneimide (PUI), were successfully synthesized from the same soft segment of poly(ethylene adipate)diol (PEA) and different hard segments via a two‐step method. The hard segment of PUU was prepared from toluene diisocyanate (TDI) and 4,4′‐diaminodiphenyl methane (MDA), while that of PUI was from 4,4′‐methylene‐bis(phenylisocyanate) (MDI) and pyromellitic dianhydride (PMDA). The structures and properties of PUU and PUI were characterized by means of FT‐IR, DSC and TGA. During the pervaporation experiment, the PUI membranes had a flux of 12.13 kg µm m^?2 h^?1 and separation factor of 8.25, while the PUU membranes had a flux of 26.35 kg µm m^?2 h^?1 and separation factor of 6.29 for 50 wt% benzene in the benzene/cyclohexane mixture at 40°C. The effects of the structures of hard segments on pervaporation performances were discussed. The investigation of the relationship in molecular structure and PV performances will be helpful for the choice and design of membrane materials in the separation of benzene/cyclohexane mixture.     

嵌段聚酯型聚脲氨酯弹性体的热转变研究

用示差扫描量热法(DSC)研究了基于二苯基甲烷二异氰酸酯(MDI)、乙二胺(ED)和聚己二酸丁二醇酯(PBA)(M.W.1975和M.W.1228)两系列嵌段聚酯型聚脲氨酯(PUU)弹性体,并考察了这些材料在不同退火条件下软段结晶的热变化。结果表明:在这些弹性体中,PBA 1975系列具有比PBA1228系列更低的软段玻璃化温度,说明前者的相分离较好.软段T_(gs)和硬段T_(gh)对硬段含量的变化不敏感.退火样品的DSC结果表明:软段结晶具有两个吸热峰,提出在软段相中存在两种晶型(P_l和P_h)的假设,分析了两种晶型产生的原因.     

硬链段浓度对RIM交联聚氨酯结构和性能的影响

用l-MDI/1,4-BDO/PPO-EO快反应体系,考察硬段浓度对聚氨酯结构与性能的影响。发现样品的交联度、模量和抗张强度随硬段浓度增加而提高,交联趋向均匀,断裂伸长率在浓度30％处出现最大值。ATR-FTIR和DSC分析表明,微相分离程度随硬段浓度增大而降低。