中空玻璃微珠在泡沫塑料中的应用研究

概括了中空玻璃微珠(HGB)在泡沫塑料中应用的研究进展。着重HGB对泡沫塑料的加工过程、泡孔结构、不同性能的影响进行了研究,并介绍了其在复合泡沫功能化方面的进展。研究表明HGB在泡沫基体中易分散,易加工,能够显著提高泡沫塑料的压缩性能,并对其耐热性能、保温性能、阻燃性能有一定的促进作用。此外,HGB在功能化方面也展现了日益突出的作用,显示出广阔的应用前景。     

Morphology evolution of a liquid crystalline polymer confined by highly packed glass beads in polycarbonate

Very long and perfectly oriented fibrils of a liquid crystalline polymer (LCP) were in situ formed in capillary flows by adding large amounts of glass beads (GB) to a polycarbonate (PC)/LCP blend. Thermodynamically the different interfacial tensions between the components made GB migrate to the LCP phase. Then the high content of GB spheres produced a confined condition, so that the LCP droplets passed through the simultaneously formed micro-capillaries, followed by being stretched into fibrils and stabilized consequently.     

空心玻璃微珠增强泡沫材料的研究和应用进展

空心玻璃微珠是一种新型无机填料,经表面改性后,与发泡基体复合,制备新型复合泡沫材料。同传统发泡材料相比,该复合材料质轻且机械性能优异,在航天航空以及深海开发等领域,特别是制备浮力材料方面,应用前景广阔。文章综述了空心玻璃微珠表面改性方式、空心玻璃微珠/发泡体复合材料的发泡方法和成型工艺,在此基础上对近年来国内外研究和应用现状进行了介绍。     

Photocatalytic inactivation of algal growth in eutrophic water with hollow glass beads

Photocatalytic inactivation of algae,Anabaena, Microcystis, andMelosira, was performed with TiO₂-coated pyrex glass beads under the illumination of UV light (370 nm wavelength). After being irradiated with UV light in the presence of the TiO₂-coated pyrex glass beads,Anabaena andMicrocystis, known as typical cyanobacteria, lost their photosynthetic activity, and the string ofAnabaena cells and the colonies ofMicrocystis cells were completely separated into individual spherical ones. In the case ofMelosira, which is a typical diatom, however, somewhat lower photocatalytic inactivation efficiency was obtained, which was believed to be due to the presence of the inorganic siliceous wall surrounding the cells ofMelosira.     

影响中空玻璃微珠填充PS复合材料性能的因素

研究了中空玻璃微珠的表面改性和粒径分布,苯乙烯-丁二烯-苯乙烯弹性体(SBS)的加入对聚苯乙烯(PS)/中空玻璃微珠复合材料力学性能的影响.结果表明:硅烷偶联剂KH550对中空玻璃微珠的表面改性效果优于KH560;粒径分布窄的中空玻璃微珠填充PS复合材料具有较高的拉伸强度、弯曲强度和冲击强度:SBS的加入可以提高复合材料的力学性能,尤其可以大幅提高简支梁缺口冲击强度.     

PVC/HGB拉伸性能的研究

应用Instron材料试验机在室温下测量了空心玻璃微珠（HGB）填充聚氯乙烯（PVC）复合材料（PVC／HGB）拉伸性能。结果表明：试样的弹性模量随着HGB体积分数（φf)的增加而线性增大；而屈服拉伸强度（σyc)和拉伸断裂能则随着φf的增加而缓慢下降，当φf为5％－20％时，PVC／HGB的断裂拉伸强度（σbc)均高于未填充PVC；HGB粒径对试样的σyc和σbc的影响不太明显。当φf为5％时，PVC／HGB的拉伸强度均高于PVC/CaCO3复合材料。     

废旧三元乙丙橡胶粉和空心玻璃微珠填充改性PP的性能

采用熔融共混挤出的方法制备了聚丙烯(PP)/废旧三元乙丙橡胶(WEPDM)粉/空心玻璃微珠(HGB)复合材料,研究了w(WEPDM)和w(HGB)对复合材料力学性能的影响.结果表明:w(WEPDM)为20％时,PP/WEPDM复合材料拉伸强度最大;WEPDM粉的加入可提高复合材料冲击强度,但会降低其弯曲应力;w(WEP...     

Effect of hollow glass beads on density and mechanical properties of silicone rubber composites

In this work, low density hollow glass beads (HGB)/silicon rubber (SR) composites were prepared by solution method and flocculation process. The prepared samples were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, tensile test, and friction test. The results show that the densities of SR composites decrease from 1.140 to 0.792 g/cm³ with the addition of HGB. By comparing theoretical density with true density, it can be estimated that the ratio of shattered HGB increase from 8.79% to 24.76%. Especially, the mechanical properties of SR composites were improved by surface modification of HGB. By adding surface-modified HGB at 5 and 10 wt%, the tensile strengths of SR composites were enhanced by 17.8% and 28.2%, respectively. In addition, tear strength, shore A hardness, compression set, and friction property were significantly ameliorated. Furthermore, the mechanism of surface-modified HGB in mechanical properties was analyzed.     

空心玻璃微珠填充改性双马来酰胺树脂复合材料耐热性能的研究

采用空心玻璃微珠填充改性双马来酰胺树脂,研究了玻璃微珠用量、粒径及表面处理对材料性能的影响,并用热机械分析仪,(TMA)测定了材料的线膨胀系数。结果表明随着玻璃微珠质量份数增加,马丁耐热温度提高,线膨胀系数呈降低的趋势,小粒径和经过表面处理的玻璃微珠对马丁耐热温度改性的效果更加显著。     

Synergistic effect between hollow glass beads and aluminium hydroxide in flame retardant EVA composites

Abstract

Flame retardant ethylene vinyl acetate (EVA) composites were prepared based on different contents of hollow glass beads (HGBs) and aluminium hydroxide (ATH) in this paper, and the flame retardant properties were studied using limiting oxygen index, UL-94 test and cone calorimeter test respectively. The results showed that EVA-4 with 1·0 wt-%HGBs has the lowest heat release rate, total heat release and smoke production rate among all samples, and HGBs could promote to form a compact char layer on the surface of the sample. It indicates that there is an obvious synergistic flame retardant effect between HGBs and ATH in this composite.     

Modification of polycarbonate by adding poly(L‐lactide)

In this study, the blend of polycarbonate (PC)/poly(L‐lactide) (PLLA) (70/30) was prepared through the conventional extrusion‐injection‐molding process. The morphology of the blend was characterized using scanning electron microscope. Both differential scanning calorimetry and wide angle X‐ray diffraction were used to investigate the crystallization behavior of PLLA component in the blend. The mechanical and thermal properties of the blend were comparatively investigated, and the hydrolytic degradation ability of the material was also evaluated. The results show that the dispersed‐PLLA particles are in the amorphous state in the PC matrix. Although the blend is immiscible, the rigid PLLA particles exhibit the toughening and reinforcement effects on PC simultaneously. Specifically, the heat‐distortion temperature of the blend is comparable to that of pure PC. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Wettability control of glass beads

Wettability plays an important role in a number of industrial applications. Often it becomes desirable to control contact angles (wettability). For this purpose, two techniques for altering the contact angles of glass beads are described. These involve chemisorption of Silicones or Hexamethyldisilazane (HMDS) on glass surfaces. The results of measured contact angles on treated glass beads indicate that by carefully controlling the treating procedure, it is possible to obtain the desired wettability.     

N2‐filled hollow glass beads as novel gas carriers for microcellular polyethylene

N₂‐filled hollow glass beads (HGB) were first used as novel gas carriers to prepare microcellular polymers by compression molding. Dicumyl peroxide was acted as crosslink agent to control the produced microcellular structure of low density polyethylene (LDPE)/HGB. The effect of temperature, pressure and the content of gel on the embryo‐foaming, and final‐foaming structure are investigated. Scanning electronic microscopy shows that the average cell size of microcellular LDPE ranges from 0.1 to 10 μm, and the foam density is about 10⁹–10¹¹ cells/cm³. A clear correlation is established between preserving desirable micromorphologies of microcellular LDPE in different processing stage and tuning processing factors. The pertinent foaming mechanism of microcellular materials foamed with HGB is proposed. Because of the good mechanical strength, low density, weak water‐absorption, and excellent heat insulate ability, microcellular LDPE has great potential application in energy building materials. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

中空玻璃微珠填充聚氨酯发泡材料的吸声性能与动态力学性能研究

以聚氨酯（PU）为基体、磷酸三甲酚酯（TCP）为增塑剂、中空玻璃微珠（HGB）和偶氮二甲酰胺（AC发泡剂）为填料,采用熔融共混法制备了软质PU/TCP、PU/TCP/HGB、PU/TCP/HGB/AC材料,研究了增塑剂TCP、填料HGB和AC发泡剂的含量对PU材料的吸声性能和动态力学性能的影响。结果表明,在一定范围内,增塑剂TCP、填料HGB和AC发泡剂的加入显著提升了复合材料的吸声性能,当TCP含量为25 %（质量分数,下同）、HGB含量为10 %、AC含量为2 %时,材料的吸声性能最佳,平均吸声系数达到0.29,且频率为1 714 Hz时吸声系数最大,为0.55;以半峰宽衡量材料的吸声频率宽度,发现在一定范围内增塑剂TCP、填料HGB和AC发泡剂对半峰宽的长度分别有减少、增加的作用,为制备轻质宽频吸声材料提供了实验依据;对PU/TCP、PU/TCP/HGB材料的动态力学性能分析进一步验证了选用25 % TCP和10 % HGB配比对材料整体性能调控的合理性。     

Conformation of polycarbonate by flow and magnetic birefringence

Solutions of polycarbonate in chloroform and tetrahydrofuran have been used to make measurements of flow birefringence, magnetic birefringence and viscosity. The results are used with standard theories of the two effects to derive optical and magnetic polarizability anisotropies of the polymer's statistical segment. These anisotropies are then used to determine the average mutual orientation of the phenyl rings in the chain and the average number of monomer units per statistical segment.     

Vane rheology of cohesionless glass beads

The rheology of a single coarse granular powder has been studied with shear vane rotational viscometry. The torque required to maintain constant rotation of a vane tool in a loose bed of glass beads (with a mean particle size of 203 μm) is measured as a function of vane immersion depth and rotational speed. The resulting torque profiles exhibit both Coulombic behavior at low rotational rates and fluid-like, collisional behavior at high rotational rates. Analyzing vane shaft and end effects allows the flow dynamics at the cylindrical and top and bottom disk surfaces of vane rotation to be determined. Disk surfaces show a uniform torque profile consistent with Coulombic friction over most of the rotational rates studied. In contrast, cylindrical surfaces show both frictional and collisional torque contributions, with significant dynamic torque increases at deep immersion depths and fast vane rotation.