几个影响PVA为粘合剂的光敏热成像材料感光性能的因素研究

本文以水性聚乙烯醇(PVA)为粘合剂，原位法合成的AgBr作为光敏元，考察了组分四氯邻苯二甲酸、酞嗪以及三溴甲基砜类防灰雾剂在体系不同pH值时对PTG材料感光性能的影响．实验结果表明：防灰雾剂可以明显地降低灰雾和减小最大密度；体系pH在7．0-7．5之间时，感光度最大，而灰雾随着体系pH的升高而增大．     

Sulfur‐free lignin as reinforcing component of styrene–butadiene rubber

The potential application of lignin biopolymer as a component of styrene–butadiene rubber was examined with regard to its ability to reinforce the vulcanizates. It was shown that the sulfur‐free lignin preparation improved physicomechanical properties of rubber. The determination of the coefficient of lignin activity confirmed that lignin acts as an active filler. FTIR characteristics of lignin isolated from the vulcanizate containing 20 phr lignin indicated its interaction with the sulfur system, resulting in formation of noncyclic sulfide structures. In the case of higher lignin amount in the vulcanizate, some interfacial interaction between lignin and SBR may occur. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 924–929, 2005     

垃圾焚烧管式布风流化床的冷态实验

在床截面为300mm×300mm、床高为4. 4m的管式布风流化床实验台上,分别对宽筛分下不同颗粒粒度、不同床层高度、不同截面流速、布风的均匀性以及非平衡布风时颗粒流化特性进行实验研究,为未来垃圾衍生燃料的流化燃烧实验提供基础数据。管式布风流化床的开孔方向与夹角大小对床层压降变化影响明显,向下开孔角度越小,动能消耗越大,但床层稳定性能好。随着料层高度增加,各布风管间的布风更趋于平衡,流化的稳定与均匀性能也越好。管组压降失衡时,床层压降不平衡明显增加,波动幅度增大,不稳定性明显高于正常流化状态。     

改性磁性壳聚糖微球的制备、表征及性能研究

以(NH4)2Fe(SO4)2.6H2O、NH4Fe(SO4)2.12H2O和壳聚糖为原料,经羟丙基化、胺基化,采用一步包埋法制备了一种新型的多胺基化磁性壳聚糖微球。通过正交实验法确定了磁性微球的最佳制备条件,即搅拌速度1200r/min,壳聚糖用量3.0g,环氧氯丙烷用量2.5mL,乙二胺用量2.5mL。并用IR、TG、XRD和SEM对其结构及形貌进行了表征。结果表明,Fe3O4磁性粒子已包埋了一层胺基化壳聚糖。磁性微球胺基含量为2.302mmol/g;呈较规则的球形,平均粒径为209nm,且具有顺磁性和良好的耐酸性。     

Surface properties of surfactants derived from natural products. Part 1: Syntheses and structure/property relationships—Solubility and emulsification

Several novel and some previously known, mostly sugar-based, surfactants have been synthesized and some of their surface properties have been characterized and compared with those of commercial nonylphenol ethoxylates. The surfactant solubility in water, ethanol, and dodecane was studied. The properties of these compounds as emulsification agents in systems composed of the surfactant with water/isopropyl myristate, water/rapeseed oil, and water/dodecane are presented. The aqueous solubility of the surfactants follows the general trend expected from their hydrophilic-lipophilic balance according to Griffin (HLBG), but it is also clear that the nature of the headgroup and the structure of the nonpolar part affect the solubility in a manner not aptured in the standard HLBG concept. An ester or amine group as the connecting unit between the hydrophile and the hydrophobe produces a more water-soluble surfactant than the corresponding amide derivative. Some effective emulsifiers were found. For instance, the surfactants with a dehydroabietic nonpolar group appear to be promosing emulsifiers. Most sugar-based surfactants were able to form macroemulsions of up to around 2 wt/vol% of oil. The stability of many of these amulsions was very high, extending for months.     

淀粉分子磁化修饰及其再生膜材料制备

以高直链淀粉（HS）为原料，通过“还原胺化-点击化学法”在其还原性端的潜在醛基上进行磁化分子修饰，得到具有磁性的变性淀粉（MMS），并在外磁场作用下制备再生淀粉膜。具体包括在HS分子唯一的潜在醛基上引入炔基，对四氧化三铁粒子（MNP）进行硅烷包覆得到叠氮化磁体粒子（azide-MNPs），两者经点击化学反应得到分子链末端带磁的变性淀粉。借助XRD、FTIR、NMR和MALDI-TOF MS对产物进行结构表征，结果表明，磁体粒子精准接枝到高直链淀粉分子还原末端，得到目标产物MMS。再生淀粉膜性能测试结果表明，在外磁场诱导条件下MMS逐渐趋于分子有序排列，制得的再生淀粉膜较纯CMS淀粉膜断裂伸长提升49.5%，断裂强度提升88.3%，短程有序程度提高。该文为基于外加磁场下的淀粉再生膜结构设计和力学性能调控提供了新思路。     

Preparation of dibasic acid-containing soy phospholipids by chemical and enzyme-catalyzed transesterification and evaluation of their surface-active properties

The preparation of dibasic acid-containing soy phospholipid was made by transesterification reaction with alkyl ester of diabasic acid with both lipase and alkoxide as a catalyst. The extent of incorporation of a dibasic acid varied with the molecular size of the dibasic acid. The extent of incorporation in soy phospholipids was 4–13% in the case of adipic acid and 9–20% in the case of sebacic acid. The surface-active properties of these modified soy phospholipids were examined and were found to be different from those of the original (unmodified) soy phospholipid. The interfacial properties such as critical micelle concentration (CMC), γ_CMC, surface excess concentration Γ_max, and minimum area per molecule (Å), and thermodynamic parameters such as standard free energy of micellization, were found to depend on the hydrophobic part of the dibasic acids.     

Rheology of poly(n‐butyl methacrylate) and its composites with calcium carbonate

Poly(n‐butyl methacrylate) (PBMA) composites with calcium carbonate (CaCO₃) were prepared by in situ radical copolymerization of butyl methacrylate (BMA) and methacrylic acid (MA) with precipitated calcium carbonate. To compare the different rheological behaviors of the monomer mixtures with CaCO₃ and the composites, the steady and dynamic viscosities of BMA/MA/CaCO₃ and poly(BMA/MA/CaCO₃) were measured by means of steady and oscillatory shear flows. The viscosity of the mixture BMA/MA/CaCO₃ was found to increase evidently with the increasing of CaCO₃%. The influence of MA% on viscosity of BMA/MA/CaCO₃ was slight. During the in situ polymerization, the viscosity of the reacting system was measured to be enhanced by a factor of about 10⁴ from the monomer/CaCO₃ mixture to composites. The dependency of zero‐shear viscosity on molar mass of PBMA was also investigated. The relation between the zero‐shear viscosity and molar mass is η₀ = 10^?15 M_w^3.5. The evolution of the viscosity with the temperature for both PBMA and its composites was obtained and time–temperature superposition was used to build master curves for the dynamic moduli. The flow activation energies were found to be 115.0, 148.6, and 178.7 kJ/mol for PBMA, composite PBMA/CaCO₃ (90/10), and PBMA/MA/CaCO₃ (89/1/10), respectively. The viscosity of the composites containing less than 10% CaCO₃ was lower than that of pure PBMA with the same molar mass. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1376–1383, 2003     

Modification of sandy soil using water‐borne polymer

A new polymeric system has been applied for structural modification of (noncompactable) sandy soils. The system is based on a water‐borne styrene acrylic polymeric formulation (emulsion) containing varying amounts of solid polymer. The present work deals with system optimization and measurements designed to examine the effects of polymer content on hydraulic conductivity and compressive strength. Samples were prepared from prescribed amounts of polymer, water, and sand by using two different preparations methods (mixing and spraying). Measurements of hydraulic conductivity for both sets of samples were conducted in a flexible membrane test apparatus. For the first set of samples, the permeability coefficient of the sand was noted to be reduced 10‐fold (from 10^?5 to 10^?6 m s^?1) upon the incorporation of about 2% polymer. In the second set (samples prepared with the spraying method), the hydraulic conductivity was further reduced to 7.2 × 10^?7 at a polymer concentration of about 2%. Stress–strain measurements made on dry cylindrical specimens disclosed remarkable enhancement in the mechanical behavior of the system. For both types of preparation methods, the compressive strength and modulus of elasticity increased linearly with the polymer concentration in the sample. Scanning electron microscopic examination revealed that the dramatic reduction in the permeability and the improved mechanical properties are attributed to the polymer coverage of the sand particles and the development of interconnecting ties between them. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2484–2491, 2003