端羟基芳香酯二醇扩链的聚氨酯－酯的DSC研究

端羟基芳香酯二醇扩链的聚氨酯－酯的ＤＳＣ研究陈静，余学海，杨昌正（南京化工学院应化系南京２１０００９）（南京大学化学系南京２１００９３）关键词嵌段聚醚聚氨酯－酯，结晶性，微观相结构，差示扫描量热法，形态结构众所周知，聚氨酯嵌段共聚物是一类结构特殊、用...     

x－甲基丙烯酸2，3－环氧丙基酯与α－甲基丙烯酸甲酯嵌段共聚物的合成与鉴定

α－甲基丙烯酸２，３－环氧丙基酯与■－甲基丙烯酸甲酯嵌段共聚物的合成与鉴定张洪敏侯元雪程■（北京化工大学高分子系北京１０００２９）关键词■－甲基丙烯酸２，３－环氧丙基酯，甲基丙烯酸甲酯，嵌段共聚物■－甲基丙烯酸２，３－环氧丙基酯（ＥＰＭＡ）含有两个可...     

核—壳结构聚丙烯酸酯—聚氨酯微乳液膜的相行为

用动态力学、红外光谱和差热分析方法研究了非交联核－壳结构聚丙烯酸酯－聚氨酯（ＰＡＣ－ＰＵ）微乳液膜的相行为．结果表明：核壳间的氢键增强了壳层软硬段间的相分离，同时破坏了硬段相中的短程有序结构，但增强了核壳相容性     

聚谷氨酸苄酯-聚乙二醇嵌段共聚物的合成和表征

通过嵌段共聚技术,合成了聚γ－苄基L－谷氨酸（PBLG）作为疏水性链段－聚乙二醇（PEG）作为亲水性链段的嵌段共聚物。用对甲苯磺酸酯化－氨水皂化法合成带有端氨基的聚乙二醇（AT－PEG）,光气－甲苯液相法制备谷氨酸苄酯－N－羟酸酐（BLG－NCA）。用AT－PEG引发BLG－NCA聚合制备PBLG－PEG或PBLG－PEG－PBLG,通过不同的单体、引发剂浓度比调节聚合物分子量。用GPC、^1HNMR、IR对聚合物的结构进行了表征。结果表明,带有端氨基的聚乙二醇确实能引发BLG－NCA生成PBLG和PEG的嵌段共聚物,产物中几乎没有残存的PEG,共聚物的分子量可控。     

甲基丙烯酸甲酯和长链烷基酯的嵌段共聚

甲基丙烯酸甲酯和长链烷基酯的嵌段共聚戴李宗＊邹友思郭金泉潘容华（厦门大学化学系厦门３６１００５）关键词阴离子聚合，甲基丙烯酸酯，嵌段共聚合，表征１９９６－０８－０７收稿，１９９６－１１－１８修回国家自然科学基金资助项目嵌段共聚合能得到具微相体系的共聚...     

苯乙烯／甲基丙烯酸和苯乙烯／甲基丙烯酸（β—羟丙酯）嵌段共聚物的表面动

通过测定表面动态接触角研究了两亲性的苯乙烯／甲基丙烯酸嵌段共聚物（PS－b－PMAA）和苯乙烯／甲基丙烯酸（β-羟丙酯）嵌段共聚物（PA－b-PHPMA）的表面动态行为及温度、嵌段长度比等因素对其值的影响，讨论了聚合物表面当接触介质改变时链段或基团的再取向行为和表面性质。     

PEO-PET嵌段共聚物的合成及其热行为研究

合成了聚氧化乙烯－聚对苯二甲酸乙二醇酯（PEO－PET）多嵌段共聚物，以红外光谱（RIR）、核磁共振谱图（NMR）对产物进行了结构表征，结果表明产物的组成与理论基本一致；利用差示扫描量效法研究了PEO－PET共聚物的热行为，发现共聚物中软段PEO与硬段PET的结晶性竞相互作用的影响。     

聚氨酯一聚丙烯酸酯共聚乳液的合成研究

以甲基丙烯酸β－羟乙酯封端的聚氨酯大分子单体与丙烯酸酯类单体进行乳液共聚，合成了以聚丙烯酸酯（PA）为主链、聚氨酯（PU）为侧链的接枝共聚物（PA－g－PU）乳液，用IR光谱和^1H NMR光谱对该聚氨酯大分子单体及PA－g－PU接枝共聚物进行了表征，并对影响聚氨酯－聚丙烯酸酯共聚合的因素进行了探讨。结果表明：聚氨酯大分子单体的加入对乳液聚合的速率造成较大的影响。该体系的表观活化自由能为99.39KJ/mol,Rp∝[I]^0.87,Rp∝[S]^0.12。     

酞侧基聚芳醚砜／对苯二甲酸乙二酯－对羟基苯甲酸嵌段共聚物共混物的研究

酞侧基聚芳醚砜／对苯二甲酸乙二酯－对羟基苯甲酸嵌段共聚物共混物的研究李刚，殷敬华，李滨耀（中国科学院长春应用化学研究所，长春，１３００２２）关键词酞侧基聚芳醚砜，热致性液晶高聚物，原位复合材料，对苯二甲酸乙二酯－对羟基苯甲酸嵌段共聚物将热塑性树脂与热...     

嵌段聚醚聚氨酯-酯热塑性弹性体的合成和性质

本文用对苯二甲酸双羟基乙二醇酯及其二聚体作扩链剂,合成了一系列聚醚聚氨酯-酯嵌段共聚物(PEUE),并用热分析法、动态力学分析、应力-应变等方法对所合成的聚氨酯材料进行了形态结构和性能关系的研究,结果表明:这类聚氨酯弹性体由于硬段具有较好的结晶性,致使材料的力学性能得到提高;另外,由于硬段酯基与软段聚醚的相互作用,材料的相容性有所改进.     

Structure-property relationships in polycaprolactone-polyurethanes

The structure-property relationships of polycaprolactone-based segmented polyurethanes were studied using differential scanning calorimetry (DSC), small-angle x-ray scattering (SAXS), wide-angle x-ray diffraction (WAXD), dynamic mechanical, and stress-strain testing. The materials studied varied in hard-segment type [4,4′-diphenylmethane diisocyanate/butanediol (MDI/BD) or 4,4′-dicyclohexyl methane diisocyanate/butanediol (H₁₂MDI/BD)], soft-segment molecular weight (830 or 2000 MW polycaprolactone), hard-segment content (23–77% by weight), and thermal history. The materials with aromatic (MDI/BD) hard segments had semicrystalline hard-segment domains, while the materials with aliphatic (H₁₂MDI/BD) hard segment had mostly amorphous domains. Materials with the shorter polycaprolactone soft segment (830 MW) exhibited thermal and mechanical behavior which indicated a considerable degree of hard- and soft-segment compatibility. The materials which contained a 2000-MW polycaprolactone soft segment exhibited better-defined microphase separation. SAXS was used to characterize the microphase structure of each system. The effects of hard-segment content and soft-segment molecular weight were similar for the aromatic (MDI) and aliphatic (H₁₂MDI) hard-segment-based block copolymers. Changing the hard segment from aromatic to aliphatic gave materials with larger interfacial area and slightly higher tensile strength. A range of morphologies between isolated hard domains in a rubbery matrix and isolated rubbery domains in a hard matrix was observed.     

Segmented polyurethanes with 4,4′-bis-(6-hydroxyhexoxy)biphenyl as chain extender. Part 2. Synthesis and properties of MDI-polyurethanes in comparison with 2,4-TDI-polyurethanes

Linear segmented polyurethanes based on poly(butylene adipate)s (PBA) of different molecular weight (M_n 2000, 1000, and 600), 4,4′-diphenylmethane diisocyanate (MDI) and the mesogenic diol 4,4′-bis-(6-hydroxyhexoxy)biphenyl (BHHBP) as well as the unsegmented polyurethane consisting of MDI/BHHBP units have been synthesized and characterized by elemental analysis, ¹³C-NMR and SEC. The thermal behavior and the morphology were studied by DSC, polarizing microscopy, and DMA. The properties of the MDI-polyurethanes were discussed in relation to the BHHBP chain extended 2,4-TDI-polyurethanes and common 1,4-butanediol chain-extended MDI products. MDI polyurethanes based on PBA (M_n 2000) exhibit a glass transition temperature T_g of about −40°C independent of the hard segment content up to ∼50% hard segments. At higher hard segment contents increasing T_gs were observed. Polyurethanes, based on the shorter polyester soft segments PBA (M_n 1000 or 600), reveal an increase in the glass transition temperatures with growing hard segment content. The thermal transitions caused by melting of the MDI/BHHBP hard segment domains are found at 50 K higher temperatures in comparison with the analogous TDI products with mesogenic BHHBP/TDI hard segments. Shortening of the PBA chain length causes a shift of the thermal transitions to lower temperatures. Polarizing microscopy experiments indicate that liquid crystalline behavior is influenced by both the content of mesogenic hard segments and the chain length of the polyester. © 1996 John Wiley & Sons, Inc.     

Soy-oil-based segmented polyurethanes

Segmented polyurethanes were prepared from soy polyol, diphenyl methane diisocyanate (MDI), and ethylene glycol or butane diol as chain extenders. Samples were prepared with true hard-segment concentrations (HSC) of about 0, 10, and 40%. Both the soft MDI–polyol and hard MDI/diol segments are glassy at room temperature. These samples were also crosslinked through the polyfunctional polyol soft segment. Partial crystallinity and phase separation were detected in samples with 40% HSC, on the basis of DSC data. Small-angle X-ray scattering shows the existence of phase separation with domain sizes of about 10 nm in the 40% HSC samples, but not in the others. The distribution of domain sizes is considerably broader for the ethylene-glycol extended system compared with that for the butane-diol case. Although the presence of hard segments lowers the crosslink density, samples with higher HSC had higher glass transition temperatures, higher strengths, higher moduli, lower swelling, lower elongation at break, and lower impact strengths. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3178–3190, 2005     

Shape memory fiber spun with segmented polyurethane ionomer

The effect of cationic groups within hard segments on shape memory polyurethane (SMPU) fibers was studied and the cyclic tensile testing was conducted to assess the shape memory effect. Mechanical properties, hard segment crystallization, and dynamic mechanical properties of SMPU ionomer fibers composed of 1,4‐butanediol (BDO), N‐methyldiethanolamine (NMDA), 4,4′‐methylenebis(phenyl isocyanate) (MDI), and poly(butylene adipate)diol (PBA) were investigated using a universal tensile tester, differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The results demonstrate that only 2 wt% NMDA can significantly change the glass transition temperature of the soft segment phase. DSC shows that the ionic group within hard segments can facilitate the crystallization of hard segments in unsteamed SMPU ionomer fibers. But for steamed fiber specimens, this effect is insignificant. Moreover, the ionic groups in hard segments with different hard segment contents (HSC) have different effects. In unsteamed fibers with 64 wt% HSC, 2 wt% NMDA increases the glass transition of soft segments from 63.5 to 70.6°C. However, in fibers with 55 wt% HSC, the glass transition temperature is lowered from 46.7 to 33.5°C. The post‐treatment, high‐pressure steaming is an effective way to remove the internal stress and subsequently improve the dimensional stability of SMPU ionomer fibers. Copyright © 2008 John Wiley & Sons, Ltd.     

A SOLID NMR STUDY OF POLYETHERESTER-UREAS

The morphology of some polyetherester-ureas were studied by ~(13)C CP/MAS and ~1H wide-line NMR spectroscopy. It was found that the HDI and MDI based polymers have well crystallized hard segments, whereas the TDI and HMDI based ones have not. For HDI/MDI based polymers, the presented results suggest that the distribution of two kinds of hard segment units is mainly in a block form. The influences of the different hard segment and chain length on the mobility of the soft segment were also studied.     

Thermal properties of poly(urethane-ester-siloxane)s based on hyperbranched polyester

Novel polyurethanes (PUs) were synthesized using hydroxy-terminated hyperbranched polyester (BH-20) and 4,4′-methylenediphenyl diisocyanate (MDI) as hard segments and hydroxy-terminated ethylene oxide-poly(dimethylsiloxane)-ethylene oxide triblock copolymer (PDMS-EO) as soft segment, with soft segment content ranging from 30 to 60 wt %. The PUs were synthesized by two-step solution polymerization method. The influence of the soft segment content on the structure, swelling behavior and thermal properties of PUs was investigated. According to the results obtained by swelling measurements, the increase of the hard segment content resulted in the increase of the crosslinking density of synthesized samples. DSC results showed that the glass transition temperatures increase from 36 to 65°C with increasing hard segment content. It was demonstrated using thermogravimetric analysis (TGA) that thermal stability of investigated PUs increases with increase of the soft PDMS-EO content. This was concluded from the temperatures corresponding to the 10 wt % loss, which represents the beginning of thermal degradation of samples.     

High performance UV cured polyurethane dispersion

Imide groups were introduced in the hard segment of UV cured polyurethane dispersion (UV-PUD) by extending the NCO terminated prepolymers with pyromellitic dianhydride (PMDA) where the soft segments were prepared from PTMG, H₁₂MDI, HDI and DMBA. It was found that imide hard segment, as compared with conventional urethane hard segment gave remarkably high mechanical properties as well as thermal stability in terms of decomposition temperature and dynamic mechanical properties at elevated temperatures, and the results were interpreted based on the partial mixing of soft segments and imide hard segments.     

Crystallization and melting behavior of the soft and hard segments in poly(ester-ether)s. I. Ethylene oxide-ethylene terephthalate segmented copolymers

The crystallization and melting behavior of a series of ethylene oxide-ethylene terephthalate (EOET) segmented copolymers with different soft segment molecular weight and hard segment weight content were studied by differential scanning calorimeter (DSC) and polarized microscope. The crystallizability of both the hard and the soft segments became worse than that of the corresponding homopolymers due to the interactions of the different segments. The crystallizability of the soft segments is mainly determined by the soft segment molecular weight, but is affected greatly by the content and the crystallinity of the hard segments. Conversely, the soft segment length and content also have a great effect on the crystallization of the hard segments. However, the melting points of the hard segments are determined by the average hard segment length. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 2918–2927, 1999     

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。