聚氨酯脲—丙烯酯酯水分散液的粒径及形态研究

研究了羰基含量、异氰权酯指数（〖－ＮＯＯ〗／〖－ＯＨ〗、聚氨酯脲与聚丙烯酸酯组成比（ＰＵＵ／ＰＡ）以及一系列制备江艺因素对聚氨酯脲－丙烯酸酯（ＰＵＡ）水分散液粒子尺寸及形态的影响。结果表明：羰基含量和ＰＵＵ／ＰＡ组成比增大或异氰酸酯指数减小都会导致分散液粒径减小;ＰＵＡ中ＰＡ含量越大,ＰＵＡ水分散液粒子形态越不规整;工艺因素如搅拌强度、升温速率等对ＰＵＡ水分散液粒子尺寸及形态的影响不符合传统乳液聚     

聚氨酯脲-丙烯酸酯水分散液的粒径及形态研究

研究了羧基含量、异氰酸酯指数（［ － ＮＣＯ］／［ － ＯＨ］） 、聚氨酯脲与聚丙烯酸酯组成比（ＰＵＵ／ＰＡ） 以及一系列制备工艺因素对聚氨酯脲—丙烯酸酯（ＰＵＡ） 水分散液粒子尺寸及形态的影响。结果表明：羧基含量和ＰＵＵ／ＰＡ 组成比增大或异氰酸酯指数减小都会导致分散液粒径减小;ＰＵＡ 中ＰＡ 含量越大,ＰＵＡ 水分散液粒子形态越不规整;工艺因素如搅拌强度、升温速率等对ＰＵＡ 水分散液粒子尺寸及形态的影响不符合传统乳液聚合的规律。     

超微粒γ-FeOOH的制备工艺研究

以ＦｅＣｌ２为原料，研究了γ－ＦｅＯＯＨ晶种制备和晶粒生长的反应温度、反应物浓度及配比、碱液滴加等工艺条件，得到了比较理想的合成工艺途径．结果表明，在晶种制备过程中温度及配比是影响晶种粒子形态和产物晶型的重要因素；在晶种的生长过程中，滴入体相的碱液的分散状态是宏观混合与微观混合共同作用的结果，而促进微观混合是选择优化生长工艺的判据．     

新型液晶／高聚物复合富氧膜的富氧性能及结构表征Ⅰ．液晶／高聚物复合膜的富氧性能研究

研究用烃橡胶和聚二甲基硅氧烷分散α、ω－对乙氧羰氧基苯甲酸聚乙二醇酯而得到聚合物分散液晶复合膜。用这种复合膜进行富氧分离，当ＰＥＥＣＢ－４．０５（４．０５为聚醚软段的数均聚合度ＤＰ）的含量超过某一临界值（约２３．０％ｗｔ）时，室温下ＳＢＲ／ＰＥＥＣＢ－４．０５／ＰＤＭＳ体系膜的氧气透过系数ＰＯ２值达７０－６３４ｂａｒｒｅｒ），增加约６０倍，分离系数仍较高。考察了各种影响因素对膜透气性能的影响。     

聚合物多元醇分散体的流变特性

聚合物多元醇分散体(以下简称分散体)是接枝聚醚多元醇、聚醚多元醇和乙烯基单体聚合物的混合物,直接用于制备高回弹、高负载和阻燃的软质和半软质聚氨酯泡沫体,是新一代聚醚多元醇产品[1].分散体用于聚氨酯工业中各种产品的生产,除要求有良好的稳定性外,其最为重要的指标是粘度应小于3000mPa·s和乙烯基单体聚合物的含量(固含量)应大于40%.但分散体的粘度,随固含量的增加呈指数性增加[2].近年来,已有既具高固含量和良好稳定性,又有较低粘度的分散体的研究报道[3].本文在不同的反应条件下,合成了分散体,测定了其流变特性和体系中微粒的大小…     

超微料γ—FeOOH的制备工艺研究

以ＦｅＣｌ２为原料，研究了γ－ＦｅＯＯＨ晶种制备和晶粒生长的反应温度，反应物浓度及配比，碱液滴加等工艺条件，得到了比较理想的合成工艺途径，结果表明，在晶种制备过程中温度及配比是影响晶种粒子形态和产物晶型的重要因素；     

共沉法制备PbTiO3微粉控制晶粒大小方法的研究

研究了超声分散作用和共沉物陈化条件对共沉法制备ＰｂＴｉＯ３微粉晶粒大小的影响，结果表明，在超声分散作用下进行共沉反应可使晶粒明显减小，并可降低ＰｂＴｉＯ３的晶化温度，共沉物在不同类型的表面活性剂水溶液中陈化效果不同，非离子型表面活性剂及其混合物可使陈化物粒子及ＰｂＴｉＯ３晶粒明显减小。     

表面活性剂对分散体系粘度影响的特殊性

通过液体石蜡的水基化分散对影响分散体系粘度的粒子大小、表面活性剂胶束和界面膜等因素进行了研究.结果表明,表面活性剂胶束对分散体系粘度的影响极为有限,而在分散相粒子界面上由表面活性剂分子所形成的界面膜是导致分散体系粘度产生变化的重要因素.实验数据表明,对于分散体系的稳定性,存在一个表面活性剂浓度变化的临界值,而该临界值所对应的是表面活性剂分子在粒子表面以最紧密和规整的方式形成的界面膜,该种界面膜使分散体系粘度达到最大值,从而最大限度地保证了分散体系的稳定性.     

Ga2O3／HZSM—5催化剂的XRD,XPS和TPR研究

利用ＸＲＤ、ＸＰＳ、ＴＰＲ等技术对Ｇａ２Ｏ３／ＨＺＳＭ－５催化剂进行表征，结果表明，催化剂中镓组分以聚集态和分散态的形式存在，其中聚集态中α－Ｇａ２Ｏ３在一定条件下可转化为β－Ｇａ２Ｏ３；分散态又可分为游离Ｇａ２Ｏ３和与ＨＺＳＭ－５产生相互作用的镓组分，催化剂预处理条件及反应一再生过程对镓的分布及状态有较大影响。     

汽车空调器压缩机用冷冻机油的研究

采用三氟化硼乙醚 (BF3·Et2 O)催化体系合成较高粘度的环氧丙烷均聚醚 ,观察了不同反应参数对聚醚粘度的影响。同时考察了不同催化剂对聚醚酯性能的影响。结果表明 ,用固体钨硅酸合成的聚醚酯较对甲苯磺酸的性能好     

多元醇法形貌可控制备氧化亚铜微纳米颗粒

以硝酸铜、乙酸铜、乙酰丙酮铜为原料,采用多元醇还原法合成制备了氧化亚铜立方体、微球、空心球、核壳结构等微纳米颗粒。 利用X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)、透射电子显微镜(TEM)、高分辨透射电子显微镜(HRTEM)和紫外可见吸收光谱(UV-Vis)等测试手段对样品的物相、形貌、元素组分及吸光性能进行了表征。 同时考察了铜源、反应时间、和多元醇类型对氧化亚铜微纳米材料形貌的影响,对产物形成机理进行了初步的探讨。 对产物形成机理进行了初步的探讨。 采用简单低廉的多元醇合成法,可以控制合成不同相貌的氧化亚铜微纳米结构。 对制备形貌可控的氧化物具有一定的指导意义。     

Formation of molecular bundles from self-assembly of symmetrical poly(oxyalkylene)-diamido acids

Sodium salts of poly(oxypropylene)-trimellitic amido acid (POP-amido acid), prepared from the reaction of POP-diamines and trimellitic anhydride, were found to self-assemble into orderly molecular bundles. The POP-amido acid has a symmetrical structure consisting of a hydrophobic POP middle block (2000 g/mol) and four symmetrical carboxyl end groups. By dissolving in water and evaporating on a polyether sulfone film, the POP-amido acid molecules self-assembled into a unique array with average dimensions of 7-13 nm in width, 2-5 nm in height, and 20-50 nm in length, observed by atomic force microscope. Varied morphologies were also observed when varying the pH, solvents, evaporating rate, concentration, and substrate surface. Unlike the common surfactants of single head-to-tail structure and the naturally occurring phospholipids of one head and two tails, the synthesized POP derivative is a symmetrical structure of four hydrophilic heads and one long hydrophobic block. Through the complementary noncovalent bonding forces, the molecules tend to align into molecular bundles or loops as the primary structure. The formation of different morphologies is controlled by the intermolecular forces including hydrogen bonding, aromatic pi-pi stacking, ionic charge, and hydrophobic interaction, in a concerted manner.     

Production of Polyether Polyols Using Phosphate Calcium Salt

The synthesis of bifunctional polyols using glycerol phosphate calcium salt hydrate as initiator and caesium hydroxide and potassium tert-butoxide as catalyst by means of anionic polymerization was achieved. If a phosphate salt is used as initiator, this reaction allows us to obtain polyols with phosphate groups in its structure not previously described. The relationship to catalyst type was also studied. The kinetic studies revealed that there was a linear relationship between the propylene oxide consumption and time. Both the polydispersity indexes of the polyol and the reaction time decreased using caesium hydroxide instead of potassium tert-butoxide under the same synthesis conditions. The incorporation of phosphorus in the polyol chain was confirmed by MALDI-TOF spectra and ³¹P-NMR spectra. GPC analyses showed an additional small peak in the product, attributed to the allyl adduct. The purification procedure of polyether polyols was also studied by means of liquid-liquid extraction, desorption and ion exchange.     

Tunable morphologies of polymer capsules templated from cuprous oxide particles for control over cell association

Over the past two decades,layer-by-layer(LbL) assembly of micro/nanocapsules has been of interest for the investigation of bio-nano interactions to explore bio-applications,such as drug delivery.The choice of an appropriate template that can be easily dissolved under mild conditions is one of the challenges for the assembly of LbL capsules.Herein,we report the engineering of LbL capsules with tunable morphologies using cuprous oxide(Cu_2O) particles as templates.Cu_2O particles with cubic,tetradecahedral or spherical morphologies were synthesized via hydrothermal processes,which can be dissolved under mild condition(e.g.,sodium thiosulfate solution).The influence of capsule morphologies on cell association was investigated,which indicates that LbL capsules with cubic geometry promoted cell association up to 4 and 9-fold than tetradecahedral and spherical capsules,respectively.The reported method provides a new avenue for the assembly of LbL capsules with different morphologies,which has the potential for better understanding of biological interactions of LbL capsules.     

Properties of acrylic–polyurethane hybrid emulsions synthesized by the semibatch emulsion copolymerization of acrylates using different polyurethane particles

Aqueous acrylic–polyurethane hybrid emulsions were prepared by the semibatch emulsion copolymerization of methyl methacrylate and butyl acrylate in the presence of eight polyurethane dispersions. The polyurethane dispersions were synthesized with isophorone diisocyanate, 1000 and 2000 molecular weight polyester polyols, 1000 molecular weight polyether polyol, butanediol, and dimethylol propionic acid. Acrylic monomers were added in the monomer emulsion feed. We studied the effect of the use of different polyurethane seed particles and the effect of different weight ratios of methyl methacrylate to butyl acrylate on the emulsion properties, microphase structure, and mechanical properties of hybrid films. The average particle size and distribution were determined by photon correlation spectroscopy. The rheological properties of polyurethane dispersions and hybrid emulsions were tested under destructive conditions by an examination of flow curves and under nondestructive conditions of oscillatory shear in a range of linear viscoelastic responses. Differential scanning calorimetry was performed to characterize the thermal‐response properties of polymeric films. The relative average molecular weights were determined by gel permeation chromatography. The interactions between the acrylic and polyurethane components in hybrid particles and particle structure were studied with infrared spectroscopy and nuclear magnetic resonance spectroscopy. Mechanical properties such as the Koenig hardness, tensile strength, elongation at break, and Young's modulus were measured. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4050–4069, 2005     

The Aqueous Dispersions of Bicontinuous Cubic Phases Formed by Precursor Method

The morphologies and the microstructures of the dispersed particles of the cubic phase, which were formed by precursor method, were studied. The freeze-fracture TEM clearly showed that the aqueous dispersed particles have irregular cubic shapes. X-ray diffraction technique has been utilized to study the microstructure of the particles and it was found that these particles still retained the cubic character. The sizes of the particles were measured by dynamic light scattering, and the results showed that the sizes of the dispersed particles were between 200～400 nm under different conditions.     

单组分阴离子聚氨酯水乳液结构与性能

聚氨酯乳液;聚醚多元醇;二羟甲基丙酸;单组分阴离子聚氨酯水乳液结构与性能     

Design,polymerization, and properties of polyurethane elastomers from miscible,immiscible, and hybridized seed‐oil derived soft segment blends

Polyester seed‐oil derived polyols have been prepared and blended with conventional polyols for making polyurethane elastomers. Miscibility was complete for polypropylene oxide/polyethylene oxide and polytetramethylene oxide (PTMEG). Blends of polyester seed‐oil derived polyols with conventional polyester polyols (polybutylene adipate and ?‐polycaprolactone) were immiscible or nearly so. Furthermore, the phase behavior (miscible vs. immiscible) did not change appreciably for each blend composition explored as a function of temperature at relevant ranges (up to the polyether ceiling temperature). This counter‐intuitive result is found to be actually consistent with calculated solubility parameters for each polyol type and the phase diagrams computed on their basis. The phase behavior of the polyols is shown to have significant effects on the properties of polyurethane elastomers where immiscible polyols cause broadening of the glass transition distribution and significant reduction of ultimate tensile properties. However, here it is shown that immiscible systems containing polyester seed‐oil derived polyols can be transesterified with the appropriate polyol partner of interest to create a new single phase polyol or that the polyester polyol monomers can also be copolymerized to make new single phase polyols, both of which result in improved polyurethane elastomer properties. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 93–102     

Elevation of modulus and elongation of semicrystalline polyurethanes

Polyurethanes were synthesized based on an amorphous polyester polyol, and different chain extenders, comparing the universally accepted symmetric chain extender (1,4‐butanediol) with an asymmetric (1,2‐propanediol) chain extender. The effect of incorporating a crystalline polyester polyol polyhexamethylene adipate (PHMA) was investigated. The resulting morphologies and tensile properties are dramatically different. Based on the thermal and infrared data obtained, the sample with the symmetric chain extender exhibits a phase‐separated morphology, which can change as a function of time and temperature. Conversely, the polyurethane with the asymmetric chain extender has a phase mixed morphology that remains stable under the same experimental conditions. Incorporating crystalline PHMA resulted in a substantial change in the mechanical properties of the materials, especially for the copolymer comprising asymmetric chain extender. The rate of crystallization and the degree of crystallization achieved depended on the type of chain extender used. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018