空心玻璃微珠表面包覆改性及其应用

本文主要综述了空心玻璃微珠表面镀膜的类型及镀膜方法,经表面包覆改性可提高空心玻璃微珠的性能或使其具有新的性能,拓宽了其应用领域,同时也探讨了空心玻璃微珠表面包覆改性及其应用的发展趋势。     

玻璃微珠增强硬质聚氨酯泡沫塑料的性能

研究了通过不同偶联剂处理后的不同玻璃微珠对全水发泡硬质聚氨酯泡沫的微观形貌、压缩强度和热稳定性的影响。试验结果表明,玻璃微珠的添加量占聚醚多元醇的6%(质量分数)以下时,玻璃微珠对泡孔形貌影响较小,并且应用偶联剂KH550处理后的玻璃微珠K46对聚氨酯泡沫的增强效果最好。在保持硬质聚氨酯泡沫密度不变的情况下,玻璃微珠K46含量为聚醚多元醇的6%时可提高压缩强度约10%,压缩模量约8%。同时,用玻璃微珠增强后的硬质聚氨酯泡沫热稳定性也有一定的提高。     

几种空心微珠的研究现状与发展

介绍了几种空心微珠(粉煤灰空心微珠、空心玻璃微珠、空心碳微珠以及其它空心微珠)的性能特点、制备方法以及在实际中的应用现状;并介绍了一种基于自蔓延高温合成技术制备空心陶瓷微珠的新方法,最后指出了各类空心微珠存在的问题及应用研究前景.     

空心玻璃微珠含量比对涂料隔热性能的影响

主要研究了自主研制的空心玻璃微珠涂料的隔热性能。通过隔热模型试验，考察了空心玻璃微珠涂料的隔热性能，对比了空心玻璃微珠含量比对涂料隔热性能的影响，并对其隔热机理和含量比的影响原因进行了探讨。指出空心玻璃微珠涂料是一种具有良好隔热性能的涂料，能产生明显的隔热效果，但过高的空心玻璃微珠含量比将对隔热性能产生劣化影响。     

空心玻璃微珠制备技术及应用研究进展

综述空心玻璃微珠结构与发展历史，玻璃粉末法、喷雾造粒法、液滴法、干凝胶法、软化学法等空心玻璃微珠制备方法，在塑料、橡胶、树脂、乳化炸药、涂料、电磁屏蔽、微波吸收等方面的应用。提出空心玻璃微珠具备质量轻、强度高、流动性好，隔热、耐腐蚀等优点，在发展隔热、耐磨等复合材料中发挥越来越大的作用，在新能源产业和生物材料中的应用获得快速发展。认为在抗压强度、粒径等方面，空心玻璃微珠达不到高性能微珠的高强度和细粒径水准，微珠化学稳定性和精细化控制程度方面也有欠缺；在改进原料配方、优化生产工艺、提高后处理技术方面，以及针对全海深浮力材料、隔热涂料、乳化炸药等的应用方面应深入开展。     

空心玻璃微珠填充改性POM的结构与性能

用空心玻璃微珠填充改性聚甲醛(POM)。研究了玻璃微珠的含量、粒径对POM／玻璃微珠复合体系力学性能、流动性和分散形态等的影响。结果表明,影响复合体系性能的主导因素是玻璃微珠在POM中的分散形态及其与POM间的界面粘结状况。用量一定的小粒径玻璃微珠可在POM中均匀分散,与POM间界面粘接好,可以提高复合体系的性能。     

空心玻璃微珠表面处理微观分析

用硅烷偶联剂对空心玻璃微珠的表面进行了处理.用红外,热分析,电镜对空心玻璃微珠进行了观测.未经偶联剂处理的空心玻璃微珠表面的OH键含量少.未经偶联剂处理的空心玻璃微珠含水量非常微小.通过电镜观察,偶联剂剂提高了环氧树脂与空心玻璃微珠的结合程度.     

玻璃微珠的提取与应用

煤粉在燃烧过程中会形成粉煤灰，在粉煤灰中存在大量的玻璃微珠。由于玻璃微珠具有许多优异特性，其应用领域很广，利用价值很高。玻璃微珠的提取有两种方法。     

空心玻璃微珠填充固体浮力材料的制备及性能研究

以双酚A环氧树脂E51为基质原料,甲基四氢苯酐为固化剂,K25空心玻璃微珠为轻质填充物,采用模压成形的方法制备了空心玻璃微珠填充固体浮力材料。研究了玻璃微珠的填充率对体系粘度、浮力材料的密度、抗压强度及耐静水压件能的影响。结果表明,低密度空心微珠的引入,有效降低了固体浮力材料的密度,并且随着玻璃微珠填充量的增大,材料的理论计算密度与实际密度的偏差逐渐变大;浮力材料的单轴压缩强度和耐静水压强度随着空心玻璃微珠填充量的增大而降低,当玻璃微珠填充量超过18％时,材料性能下降幅度增大。     

空心玻璃微珠填充固体浮力材料的制备及性能研究

以双酚A环氧树脂E51为基质原料,甲基四氢苯酐为固化剂,K25空心玻璃微珠为轻质填充物,采用模压成形的方法制备了空心玻璃微珠填充固体浮力材料。研究了玻璃微珠的填充率对体系粘度、浮力材料的密度、抗压强度及耐静水压性能的影响。结果表明,低密度空心微珠的引入,有效降低了固体浮力材料的密度,并且随着玻璃微珠填充量的增大,材料的理论计算密度与实际密度的偏差逐渐变大;浮力材料的单轴压缩强度和耐静水压强度随着空心玻璃微珠填充量的增大而降低,当玻璃微珠填充量超过18%时,材料性能下降幅度增大。     

The effect of glass bead content on the mechanical properties of acrylonitrile/styrene/acrylate copolymer

The influence of glass bead content and the loading rate on the mechanical properties of polyacrylonitrile/styrene acrylate (ASA) copolymer was investigated. For this copolymer, tensile yield strength and work to fracture were significantly reduced as the bead content was increased. Tensile yield strength decreased linearly with increasing glass bead content according to the Leinder equation. It was found that the variation of tensile yield strength with log (loading rate) follows that of Eyring's equation for yielding. The presence of the weldline reduced the tensile yield strength of both unfilled and filled materials. Flexural modulus and flexural strength also varied in a predictable fashion with glass bead concentration. The increase in modulus with glass bead content followed Kerner's equation.Crack growth resistance values of the unfilled ASA and its composites were measured at three loading rates using the generalized locus method. It was found that the resistance to steady crack propagation,J _R, was a sensitive function of glass bead content and loading rate. Within the range of these experiments,J _R decreased with increasing glass bead content and loading rate.     

耐高温防腐隔热涂料的制备与性能

耐高温防腐隔热涂料在石化管道领域具有重要的应用。文中以环氧改性有机硅树脂为基料,通过复配具有优异隔热性能的空心玻璃微珠、低温熔融玻璃粉、润湿分散剂、消泡剂等制备了一种至少耐500℃高温的防腐隔热涂料。利用扫描电子显微镜、热导分析、电化学阻抗谱,研究了不同颜基比、空心玻璃微珠含量对涂料力学性能和热学性能的影响。研究表明,颜基比为2/1,空心玻璃微珠占填料比例为40%时涂层综合性能达到最佳。     

中空玻璃微珠粒度分布分形特征及其与空隙率关系的研究

为研究中空玻璃微珠粒度分布分形特征与空隙率的关系,测量了6种中空玻璃微珠的粒度累积分布,用统计学概念与分形理论分别考察了中空玻璃微珠的粒度分布法则及其分形特征。结果表明:中空玻璃微珠粒度累积频率与相应的上限粒径的对数值有良好的线形关系,粒度符合对数正态分布法则;各中空玻璃微珠的粒度累积频率与粒径与最大粒径比值的双对数值呈线形关系,相关系数在0.95～0.98之间,强的相关表明各中空玻璃微珠的粒度分布的分形结构是客观的;随着中空玻璃微珠粒度分布分形维的增加,其空隙率减少。     

玻璃微珠改性聚丙烯的熔融、结晶与形态

采用玻璃微珠改性聚丙烯并对复合材料的熔融、结晶行为与形态结构进行了研究.结果表明,玻璃微珠一定程度上起到了异相成核作用,有利于PP的结晶,提高了结晶速率.与单螺杆挤出复合材料相比,双螺杆挤出复合材料的塑化效果较好,玻璃微珠与基体的粘接情况也较好.冲击断面呈现典型的脆性断裂特征,玻璃微珠大量蓄积在冲击断面.而拉伸破坏断面表现出显著的塑性变形,形成大量带状或纤维状形变区域,材料最终的拉伸性能则取决于玻璃微珠与基体粘接和脱粘的综合效果.     

Effects of reinforcement filler and temperature on the stability of β-crystal in glass bead filled polypropylene

The effects of crystallization temperature (T_c), glass bead content and its size on the formation of β-crystal and structural stability of originally formed β-crystal in glass bead filled polypropylene (PP) were examined. The differential scanning calorimetry (DSC) measurements indicated that the amount of β-phase in PP crystals was a function of the crystallization temperature and glass bead content. For a constant crystallization temperature, it was observed that the amount of β-crystal initially increased with increase in glass bead content up to 30 wt.%, and then decreased slightly with further increase in the filler content. From the DSC data, a disorder parameter (S) was derived to define the structural stability of originally formed β-crystals. The structural stability of originally formed β-crystals was enhanced with increase in either the crystallization temperature or the glass bead content. Also, the influence of glass bead size (4–66 μm) on the formation and stability of β-crystals in PP/glass bead blends was studied. Large glass bead particles suppressed the formation and decreased the stability of β-crystals.     

Crack propagation in polymeric composites

The velocities of rapidly moving cracks in polymethylmethacrylate, an epoxy resin, a rubber modified epoxy resin, coupled and decoupled glass bead filled epoxies and randomly oriented glass fiber reinforced epoxies were measured with a crack propagation gage that was electrolissecally plated on the surfaces of the materials.

When fracture was initiated from a natural crack it was found that the velocity conformed to Mott's equation , while fracture initiated from a blunted notch resulted in a velocity that conformed to Dulany and Brace's equation . A general energy balance was used to show how one could develop these two equations as bounds to the velocity of catastrophic crack propagation.

The terminal crack velocity in the unfilled materials and the glass bead filled materials was , where E/ρ was the modulus to density ratio of the matrix phase at the macroscopic strain rate of the fracture test. The proportionality constant of 0.28 was independent of matrix type, temperature and degree of adhesion. Cracks in the rubber reinforced epoxies always tended to become blunt, resulting in breaking loads that were higher than that expected for materials possessing a natural crack. In addition, the average terminal velocity was less than 0.28√E/ρ, indicating the retardation effects of the rubber particles. These facts were used to explain the higher fracture toughness of these composites.

Fracture surface roughness was primarily a function of crack extension and breaking stress and was less sensitive to crack velocity. An empirical modification of the Mott energy balance was used to qualitatively explain this behavior.     

Preparation and properties of hollow glass bead filled silicone rubber foams with low thermal conductivity

Silicone rubber foams filled with various content and different particle size of hollow glass bead (HGB) were prepared by compression molding. It was revealed that compared with silica filled silicone rubber foams, HGB filled materials achieved higher foaming extent, lower thermal conductivity, and lower hardness, which can be significant for thermal insulation materials. For HGB filled materials, the morphology indicated the average cell size decreased with higher HGB content and larger particle size of HGB. The density, thermal conductivity, hardness and tensile strength increased with higher HGB content and larger particle size of HGB.     

中空玻珠/超微铁核壳复合粒子的制备与微观结构的表征

用ATPU作表面活性剂制备出了超微铁包裹中空玻珠核壳复合粒子,详细地研究了中空玻珠的性质以及ATPU的用量对中空玻珠/超微铁核壳复合粒子的微观结构的影响。结果表明:粒径小、分布窄以及适当用量的空心玻璃微珠,有利于制备出小粒径的超微铁均匀致密包裹空心玻珠的核壳结构复合粒子;ATPU的用量也会对复合粒子的结构与形貌有较大的影响。     

Thermal conductivity of porous materials as a function of moisture content

Results are presented of studies of the thermal conductivity of porous materials (including cermets, fireclay ceramics, and glass bead models) as a function of moisture content.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 21, No. 2, pp. 296–300, August, 1971.