三种有机泡沫材料的吸放水性及微观结构研究

采用重量法和扫描电镜研究了硬质聚氨酯泡沫塑料、硅橡胶泡沫材料、半硬质自结皮聚氨酯泡沫塑料的吸、放水性能和微观结构,比较了这三种泡沫材料的吸、放水性能及其机理。结果表明,这三种有机泡沫材料的吸、放水能力不同,硬质聚氨酯泡沫塑料的吸、放水能力<硅橡胶泡沫材料<半硬质自结皮聚氨酯泡沫塑料,其吸、放水机理与泡沫开孔有关,密度越小且泡孔开孔率越高,吸、放水能力越强。     

醇-磷酸酯法降解废旧聚氨酯的研究

选用不同的降解剂,采用醇-磷酸酯法降解废旧聚氨酯泡沫,对降解产物进行性能测试。结果表明：以一缩二乙二醇和磷酸三正丁酯为降解剂降解聚氨酯软质泡沫效果较好。以降解产物作为部分原料制备聚氨酯硬质泡沫塑料体,对其性能测试并与不加降解产物制备的聚氨酯硬质泡沫体比较,结果表明：降解产物作为部分原料对聚氨酯硬质泡沫塑料的性能影响不大。     

三种泡沫材料的吸放水性及微观结构

采用重量法和扫描电镜研究了硬质聚氨酯泡沫塑料、硅橡胶泡沫、半硬质自结皮聚氨酯泡沫的吸、放湿水性能和微观结构,比较分析和探讨了3种泡沫材料的吸、放水性及其机理,并提出减少泡沫材料中水份的有效途径.研究结果表明3种泡沫材料的吸、放水性不同,即硬质聚氨酯泡沫塑料＜硅橡胶泡沫＜＜半硬质自结皮聚氨酯泡沫,其吸、放水机理是由于开孔所致,如果密度越小且泡孔开孔率越高,则吸、放水能力越强.减少泡沫材料中水份的有效途径(1)提高材料密度和闭孔率;(2)在材料表面镀金属膜或保留表皮;(3)进行适当干燥处理,并尽可能降低存放环境湿度.     

增强硬质聚氨酯泡沫塑料的吸湿效应研究

对两种增强硬质聚氨酯泡沫塑料在不同温湿度条件下的吸湿性能和力学性能进行了研究.结果表明,增强硬质聚氨酯泡沫塑料在初始阶段吸湿较快,随着时间的延长其吸湿率的变化逐渐变缓,同时其吸湿率随着环境温湿度的增高而明显增大;相同环境条件下,玻璃微珠增强硬质聚氨酯泡沫塑料的吸湿率明显高于玻璃纤维增强聚氨酯泡沫塑料的吸湿率;吸湿量对增强硬质聚氨酯泡沫塑料力学性能的影响较小.     

短切碳纤维增强硬质聚氨酯泡沫复合材料压缩强度与形貌研究

本文研究了短切碳纤维增强硬质聚氨酯泡沫复合材料的压缩强度和形貌.探讨了不同短切碳纤维含量对硬质聚氨酯泡沫力学性能的影响,利用光学显微镜和扫描电镜观察了不同短切碳纤维含量情况下,硬质聚氨酯泡沫复合材料泡孔形成情况及试样破坏的微观相貌.研究结果表明,当短切碳纤维含量为30％时,硬质聚氨酯泡沫复合材料的压缩强度最大,泡体泡孔均匀致密;当短切碳纤维含量超过30％后,开始出现了大量闭孔和塌泡,碳纤维与聚氨酯泡孔剥离,力学强度下降.     

玻纤增强硬质聚氨酯泡沫塑料研究进展

主要介绍近年来玻璃纤维增强硬质聚氨酯泡沫塑料的成型方法、力学性能及形态结构等方面的研究进展，探讨了玻璃纤维增强硬质聚氨酯泡沫塑料的增强机理，详细讨论了玻璃纤维的长度、含量对增强硬质聚氨酯泡沫塑料力学性能的影响。     

硬质聚氨酯泡沫压缩性能增强研究进展

从纤维增强、粒子增强、混杂增强3个角度介绍了不同增强体对硬质聚氨酯泡沫压缩性能的增强改性效果,阐述了各类增强体的增强机理与特点,讨论了表面改性对增强效果的影响,并对不同增强体提高硬质聚氨酯泡沫压缩性能的发展趋势作出展望。     

硬质聚氨酯泡沫塑料研究进展

介绍了合成硬质聚氨酯泡沫塑料的主要原料,包括主体成分和发泡剂、泡沫稳定剂等;对硬质聚氨酯泡沫塑料的物理性能,如力学性能、阻燃性能、老化性能等及其在工程上的应用情况进行了综述。     

聚醚改性硅油

中国已成为全球聚氨酯泡沫体行业最具成长性的市场之一。在2010年5月28日于深圳会展中心举行的第八届中国国际聚氨酯展览会（PU China 2010）上,迈图隆重推出了一系列新型聚氨酯泡沫添加剂,包括块状聚氨酯软泡、模塑泡沫、硬质泡沫塑料及特殊海绵泡沫。     

国外聚氨酯泡沫塑料工业(连载)

三、聚氨酯泡沫塑料制品 (三)硬质聚氨酯泡沫塑料硬质聚氨酯泡沫塑料(简称硬质泡沫或硬泡),具有绝热效果好、比强度大、成型工艺简单等特点。广泛地用作绝热保温材料、结构材料以及“合成木材”等。在日本、美国等国家中,硬质泡沫主要用途是用做设备绝热、冷库、冷冻机、船舶、车辆等绝热     

Reinforcing biopolymer hydrogels with ionic‐covalent entanglement hydrogel microspheres

Microscopic hydrogel spheres can be used to improve the mechanical properties of conventional hydrogels. We prepared ionic‐covalent entanglement (ICE) hydrogel microspheres of calcium cross‐linked gellan gum and genipin cross‐linked gelatin using a water‐in‐oil emulsion‐based processing technique. The method was optimized to produce microspheres with number average diameter 4 ± 1 µm. These ICE microspheres were used to reinforce gelatin hydrogels and improve their compressive mechanical properties. The strongest microsphere reinforced hydrogels possessed a compressive mechanical stress at failure of 0.50 ± 0.1 MPa and a compressive secant modulus of 0.18 ± 0.02 MPa. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40557.     

二元溶剂体系对泡沫传输制备聚苯乙烯微球的影响

采用二氯甲烷（DCM）和丙酮（AC）组成二元溶剂体系,考察了二元溶剂体系对制备聚苯乙烯（PS）微球时泡沫的传输和微球性能的影响,并探讨了对应的作用机理。实验结果表明,随着AC质量分数的增加,体系的出泡温度升高,PS微球的平均粒径下降且粒径分布逐渐变窄,微球的结构由多孔逐渐演变为中空。这主要是由于AC对水具有一定的亲和性,会往连续相迁移,改变连续相的表面张力,并在油水界面形成一个AC/DCM的混合液膜层,该液膜层改变了溶剂挥发的过程,最终实现对微球粒径和结构的调控。     

Effect of preparation conditions on the properties of microspheres prepared using an emulsion-solvent extraction process

Methylaluminoxane microspheres were prepared using a hydrocarbon-in-perfluorocarbon-emulsion solvent extraction process. The effect of the preparation conditions on the size of the microspheres was investigated. As expected, the size of the microspheres decreased with increasing stirring speed. At low surfactant concentrations the size of the microspheres was independent of the surfactant concentration. However, the size of the microspheres decreased as the surfactant concentration was further increased. The size of the microspheres was not only affected by the surfactant concentration but also by the volume ratio of the dispersed phase to the continuous phase. At a low volume ratio of the phases the effect of the surfactant on the size of the microspheres was larger than the effect of the increased volume ratio of the phases. At high volume ratios of the phases the effect of the volume ratio of phases on the size of the microspheres became more significant than the effect of the surfactant. A slow solidification increased the formation of non-spherical microspheres.     

Genipin-cross-linked silk fibroin microspheres prepared by the simple water-in-oil emulsion solvent diffusion method

This work describes for the first time the preparation of cross-linked and non-cross-linked silk fibroin (SF) microspheres using the simple water-in-oil emulsion solvent diffusion method. Aqueous SF solution and ethyl acetate were used as water and oil phases, respectively. Span80, oil-soluble emulsifier was found to induce the formation of SF microparticles that are completely spherical in shape and smooth in surface. SF microsphere sizes were found to depend upon various process parameters. The SF microsphere matrices showed predominantly random coil conformation. It was possible to fabricate genipin-cross-linked SF microspheres by cross-linking SF solution with genipin before microsphere formation. Both non-cross-linked and genipin-cross-linked SF microspheres contained porous structures. Percentage of dissolution in water decreased and density values of the SF microspheres increased when increasing the genipin ratio and cross-linking time. The genipin cross-linking induced SF conformational transition from random coil to β-sheet form but the size and shape of the SF microparticles did not change. It is suggested that these SF microspheres might be suitable microcarriers for hydrophilic drug delivery.     

磁性壳聚糖微球的制备及其对2，4-二氯苯酚的吸附

采用反相悬浮聚合法合成了磁性壳聚糖微球,平均粒径不超过5μm。将其用于2,4-二氯苯酚的吸附研究。考察了吸附时间、吸附温度、DCP浓度以及磁性壳聚糖用量等因素对氯酚吸附的影响。结果表明,温度对吸附影响不大,最佳吸附时间为2h时,吸附剂磁性壳聚糖微球用量为1g。对DCP的吸附率在80％以上。在最佳条件下的吸附容量为1．70mg／g。     

缓释破伤风类毒素微球的制备及其免疫原性

目的 用可生物降解缓释微球,单剂投递破伤风类毒毒。方法 用溶剂挥发法,将破伤风类毒素(TT)包入两种丙交酯-乙交酯共聚物制备成微球,用电镜观察微球的粒经与表面形态,用Bradford法及SDS-PAGE检测微球内蛋白含量及抗原结构的变化。TT微球免疫豚鼠后,观察抗体应答。结果 微球表面光滑,成球规律,两种微球平均粒径为8.4μm及9.7μm,包裹率为48％及56％,包裹后的TT结构未改变。TT微球免疫豚鼠后,1针诱导的抗TT-IgG及中和抗体滴度与3针铝吸附TT相似;TT微球免疫血清及铝吸附TT免疫血清与游离破伤风毒素有相似的结合特性。加强免疫后,TT微球的回忆应答优于铝佐剂疫苗。结论 可生物降解缓释微球单剂投递破伤风类毒素,可产生持续高的免疫应答。     

Fabrication of Gelatin/Chitosan Microspheres with Different Morphologies and Study on Biological Properties

Gelatin/Chitosan (Gel/Cs) microspheres were prepared by emulsion-coagulation method using glutaraldehyde as cross-linker. The influence of treatment methods, including removing water by different concentration of acetone/water solution and freeze-drying, on surface morphology was investigated, and the biological properties, such as cell cytotoxicity and hemolytic test, were also studied. The experimental results indicated that collapsed and aggregative, wrinkled and smooth Gel/Cs microspheres was obtained when treated by pure acetone, acetone/water solution (volume ratio of 7:1) and acetone/water solution (volume ratio of 3:1), respectively. The microspheres with porous structure were prepared when the obtained smooth Gel/Cs microspheres were treated by freeze-drying method. The cytotoxicity test result demonstrated that no significant cytotoxicity of the Gel/Cs microspheres against L929 mouse fibroblasts was observed. The hemolytic test suggested that the Gel/Cs microspheres, with a hemolytic index of 1.03%, did not have an obvious hemolytic reaction.     

Silk fibroin microspheres prepared by the water-in-oil emulsion solvent diffusion method for protein delivery

Silk fibroin (SF) microspheres were prepared by the simple water-in-oil emulsion solvent diffusion method without any surfactants. Aqueous SF solution and dichloromethane were used as water and oil phases, respectively. Influence of water: oil phase ratios on SF microsphere characteristics was investigated. From FTIR spectra, the resulting SF microspheres showed predominantly random coil SF conformation. SF microspheres observed from SEM images were spherical with deflated surfaces in some cases. Particle sizes of the SF microspheres were in the range 45–92 μm. Finally, bovine serum albumin (BSA) was used as a model protein for entrapment within the SF microspheres. The BSA-loaded SF microspheres were larger than unloaded SF microspheres. In vitro release tests indicate that BSA release from the SF microspheres was influenced by BSA content.     

Preparation and Characterization of Carboxymethyl Chitosan and β-Cyclodextrin Microspheres by Spray Drying

Three kinds of carboxymethyl chitosan/β-cyclodextrin microspheres loaded with theophylline were prepared by spray drying intended for pulmonary delivery. Mucociliotoxicity, permeation rate, and drug release characteristics of the product were investigated. The microspheres obtained by spray drying were found to be spherical with smooth or wrinkled surfaces. The mean particle size was between 3.39 and 6.06 µm. The microspheres demonstrated high product yield (43.7–50.2%), high drug loading (13.7–38.1%), and high encapsulation efficiency (86.9–92.8%). FT-IR indicated that there were interactions of theophylline with carboxymethyl chitosan matrix. Further studies on mucociliotoxicity and permeation confirmed that microspheres had better adaptability and high permeation rate. In vitro drug release from the microspheres was not related to the drug/polymer ratios.     

Preparation of polyethersulfone/sulfonated polyethersulfonephenylethane microspheres and its application for the adsorption of bisphenol A

A novel kind of sulfonated polyethersulfonephenylethane (SPESPE) was successfully synthesized firstly in this work. Then the SPESPE was introduced in polyethersulfone (PES) microspheres prepared by the electrospraying technique. The microspheres were applied to adsorbing bisphenol A (BPA) from its aqueous solution. Compared with the PES microspheres, the adsorption capacity of PES/SPESPE microspheres for BPA was increased significantly. Furthermore, the adsorption capacity of PES/SPESPE microspheres was enhanced by increasing the amounts of SPESPE in the microspheres. The pH of solution had influence on the adsorption capacity of PES/SPESPE microspheres. The kinetic data of adsorption were found to follow pseudo‐second‐order model. The Freundlich isotherm model was suitable to describe the equilibrium adsorption data. The microspheres also showed excellent regeneration and reuse ability. These results indicated that the PES/SPESPE microspheres have the potential to be used in environmental application. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43066.