苯丙乳液改性砂浆的微观结构与性能(英文)

用2种具有不同性质的苯丙乳液来研究聚合物对砂浆各种性能的影响,测量了不同聚合物掺量下,聚合物改性砂浆的流动性及力学性能.通过测量砂浆凝结硬化过程中绝热温升来研究聚合物对砂浆中水泥水化过程的影响.用扫描电子显微镜观察了聚合物改性砂浆的微观结构.结果表明:由于聚合物成膜及其与水泥水化产物的相互作用.砂浆的力学性能得到显著改善.聚合物的性质不同,对砂浆性能的影响作用不同.环境扫描电子显微镜对新拌水泥浆的原位观察证实了乳液聚合物粒子在水泥颗粒上的迅速吸附,为解释聚合物对新拌砂浆流动性能的改善以及对水泥水化的延滞作用提供了直接证据.     

Synthesis and characterization of polyurethane cationomer/MMT hybrid composite

BACKGROUND: The development of polymeric nanocomposites incorporating intercalated or exfoliated layered silicate clays into the organic matrix has been substantially motivated by the significant improvements induced by the presence of the inorganic component. Moreover, understanding and controlling the dispersion of inorganic layers into segmented polyurethane matrices by means of ionic interactions, and exploiting these interactions to enhance physicomechanical behaviour, could be of great interest in the field of polymer nanocomposites. RESULTS: New cationic polyurethane elastomers were prepared starting from poly(butylene adipate)diol (M_n = 1000 g mol^?1), 4,4′‐diphenylmethane diisocyanate, 1,4‐butanediol and N‐methyldiethanolamine or N,N′‐β‐hydroxyethylpiperazine, used as potential quaternizable moieties. The characterization of the polymers was achieved using specific analyses employed for the macromolecular samples (Fourier transform infrared and ¹H NMR spectroscopy, thermogravimetric analysis (TGA), gel permeation chromatography). An extension of our research on polymers reinforced with organically modified montmorillonite (OM‐MMT) in order to prepare hybrid composites with improved properties was performed and the resulting materials were characterized using TGA, X‐ray diffraction, atomic force microscopy and scanning electron microscopy. Also, the mechanical properties of the cationic polyurethane/OM‐MMT composites were investigated in comparison with the pristine ionic/non‐ionic polymers and their composites containing non‐ionic polymer blended with OM‐MMT or ionic polymer and unmodified MMT. CONCLUSION: The insertion of the organically modified clay into the polymeric matrix gave an improvement of the mechanical properties of the polyurethane composites, especially the tensile strength and stiffness of the hybrid materials. Copyright © 2009 Society of Chemical Industry     

水性聚氨酯涂料的制备与应用

水性聚氨酯涂料主要有单组分水必聚氨酯涂料，双组分水性聚氨酯涂料及改性水性聚氨酯涂料，介绍了这三种涂料的制备方法及其在建筑，汽车，木器家具，皮革涂饰方向的应用。     

环氧树脂改性PUA乳液的合成及性能研究

以异佛尔酮二异氰酸酯（IPDI）、聚醚二元醇（N220）、二羟甲基丙酸（DMPA）、1，4-丁二醇（BDO）和甲基丙烯酸甲酯（MMA）为主要原料合成了脂肪族聚氨酯-丙烯酸酯复合乳液（PUA），并用环氧树脂对其进行了改性。研究了nNCO／nOH比、DMPA添加量、环氧添加方式及添加量对其性能的影响，结果表明，当nNCO／nOH为1．35-1．4、DMPA为6％～7％时，以环氧和BDO一起加入，环氧添加量在2％～3％时能获得综合性能较好且贮存稳定的聚氨酯丙烯酸酯复合乳液。     

TDI-TMP聚氨酯固化剂合成的影响因素

以TDI和TMP为原料合成了低游离TDI、浅色的TDI-TMP型固化剂,讨论了TDI与TMP投料比、反应温度、催化剂用量等工艺条件对低游离浅色TDI-TMP型固化剂产品的TDI游离含量、粘度、色度、稳定性等指标的影响。结果表明,制备TDI-TMP型固化剂的最佳工艺条件:当nTDI/nTMP为3.0～3.2时,选用多次加料法,温度选择在50～60℃之间使NCO基和OH基反应,并在70℃保温使反应趋于完全;催化剂质量分数为0.4‰左右(按固体质量分数为50%计);阻聚剂质量分数为1.5‰～3.0‰;抗氧剂质量分数一般在4‰左右时,游离TDI符合TDI-TMP型固化剂行业技术指标。     

Miscibility and thermal and dynamic mechanical behaviour of semi‐interpenetrating polymer networks based on polyurethane and poly(hydroxyethyl methacrylate)

The thermodynamic miscibility and thermal and dynamic mechanical behaviour of semi‐interpenetrating polymer networks (semi‐IPNs) of crosslinked polyurethane (PU) and linear poly(hydroxyethyl methacrylate) (PHEMA) have been investigated. The free energies of mixing of the semi‐IPN components have been determined by the vapour sorption method and it was established that the parameters are positive and depend on the amount of PHEMA in the semi‐IPN samples. Thermal analyses glass transition temperatures evidenced two in the semi‐IPNs in accordance with the investigation of the thermodynamic miscibility of these systems. Dynamic mechanical analysis revealed a pronounced change in the viscoelastic properties of the PU‐based semi‐IPNs with different amounts of PHEMA in the samples. The semi‐IPNs have two distinct tan δ maxima related to the relaxations of the two polymers in their glass temperature domains. The temperature position of PU relaxation maximum tan δ is invariable but its amplitude decreases in the semi‐IPNs with increasing amount of PHEMA in the systems. The tan δ maximum of PHEMA is shifted to a lower temperature and its amplitude decreases with increasing amount of PU in the semi‐IPNs. The segregation degree of components α was calculated using the viscoelastic properties of semi‐IPNs. It was concluded that the studied semi‐IPNs are two‐phase systems with incomplete phase separation. The different levels of immiscibility lead to the different degree of phase separation in the semi‐IPNs with compositions. Copyright © 2004 Society of Chemical Industry     

提高聚氨酯耐紫外老化性的研究进展

介绍了聚氨酯材料的光老化机理,综述了采用紫外线吸收剂(UV-P,UV-328,UV-B83等)和抗氧剂(BHT,抗氧剂1135,抗氧剂PUR 67,抗氧剂PUR68等)提高聚氨酯耐紫外光老化性的研究进展。研究表明,将几种稳定剂组合使用可使聚氨酯获得最佳的稳定效果。     

聚氨酯柔性固化剂的合成及增韧环氧树脂的研究

运用分子设计的方法合成出了端胺基聚氨酯(ATPU)结构的聚氨酯柔性固化剂,用FT-IR表征了ATPU的分子结构,通过DSC和TG等表征了ATPU/EP固化过程的特性及固化产物的性能。结果表明,红外光谱分析证实了ATPU的结构符合分子设计要求;ATPU/EP固化体系相对于未改性的乙二胺/EP固化体系,其柔韧性和抗冲击性都有很大提高;ATPU/EP固化物在热分解后期表现出更好的热稳定性。     

年产120吨聚丙烯酸钠絮凝剂的工艺设计与投产

介绍了新开发的生产工艺过程及工艺条件，对120吨/年的工厂设备选型、工厂经济分析及其应用效果作了简要评述。