STUDY ON PHASE-SEPARATION OF PMMA/SAN BLENDS INDUCED BY GLASS BEADS THROUGH DYNAMIC RHEOLOGICAL MEASUREMENTS

Based on the premise that the addition of glass beads （GB） could hardly influence the linear viscoelasticity in low frequency （ω） region for homogeneous polymer systems, the dynamic rheological behaviors of unfilled and filled poly（methyl methyacrylate） （PMMA）/poly（styrene-co-acrylonitrile） （SAN） blends were studied in order to explore the effect of GB on the phase-separation of binary polymer matrix. Results show that GB has an induced effect on the phase-separation, which embodies that the phase-separation temperature （Ts） of PMMA/SAN blend filled with GB is lower than that of the unfilled system. The higher content of GB, the higher is the ＂secondary plateau＂ of ω in the terminal region of storage modulus （G＇） versus ω plot. The ＂secondary plateau＂ appearing in the terminal region is attributed to the phase-separation of PMMA/SAN blends and it becomes more fiat for filled polymer blends under the same conditions. However, it is suggested that this kind of ＂induced effect＂ is related to the GB content; the higher content of GB particles might enhance the interaction between the particles and polymer matrix. Moreover, it is found that the addition of GB also has an influence more or less on the morphology and domain size of polymer matrix. It is believed that the plot of dynamic viscosity （η＇） versus the loss viscosity （η＂） is sensitive to examine the effect induced by GB on the phase-separation of binary polymer matrix.

EFFECT 0F INTERFACIAL ADHESION ON CRYSTALLIZATION AND MECHANICAL PROPERTIES OF POLY (ETHYLENE TEREPHTHALATE)/GLASS BEAD COMPOSITES

The interfacial adhesion between poly (ethylene terephthalate) (PET) and glass beadwas investigated by scanning electron microscope and parallel-plate rheometer. Effect ofinterfacial adhesion on the crystallization and mechenical properties of PET/glass beadcomposites was also studied by differential scanning calorimeter and mechanical testers.The results obtained indicate that the glass bead has a heterogeneous nucleation effecton the PET crystallization. Although better interfacial adhesion is advantageous to theincrease of the tensile strength of the composite, yet it is unfavorable to the crystallizationof PET. It should be pointed out that the crystallization rate of filled PET is always higherthan that of pure PET, regardless of the state of interfacial adhesion.

Triaxial test on glass beads simulating coarse-grained soil

It is feasible to study the mechanical characteristics of coarse-grained soil by simulated granular materials such as glass beads.In this paper,3 mm diameter glass beads are used to conduct drained and undrained triaxial tests under different confining pressures to explore their strength,deformation and critical state characteristics.Specifically,the influence of drainage and confining pressure on the stick-slip phenomenon of glass beads is reported.The experimental findings from triaxial tests show that the stress-strain relationship of glass beads softens when the confining pressure is high.Under the undrained condition,the initial modulus increases with the increase in the confining pressure.In contrast,it is not significantly affected by the confining pressure in the drained condition.It is quite evident that the glass beads hardly contract during the shearing process,and their stress path is approximately a segmented straight line.The slope of the critical state line under the undrained condition is greater than that under the drained condition,and the friction angle of the glass beads under the undrained and drained conditions is calculated to be 28.1and 29.5,respectively.The phenomenon of stick-slip has been depicted for the different test conditions,and the stick-slip amplitude linearly increases with the confining pressure,especially in the undrained condition.It is also found that the maximum energy released from the phenomenon of stick-slip increases linearly with the confining pressure.

Effect of Fe_(2)O_(3) on the Formation of Micro Glass Beads under Air Staged Combustion

The effect of Fe_(2)O_(3) on the formation of micro glass beads(MGBs)under air staged combustion was studied.The experimental temperature was 1450℃,and Hegang bituminous coal was used as the experimental object.X⁃ray diffractometer(XRD),ash fusion tester,viscosity formula and scanning electron microscopy(SEM)were used to analyze the fly ash.Nano Measurer 1.2 software was used to measure the diameter of MGBs.The results showed that with the increase of Fe_(2)O_(3) in Hegang coal,the glass phase in fly ash first increased and then decreased.When the amount of Fe_(2)O_(3) was 15%,the content of the glass phase was the highest,which was 51.26%.The ash melting point first decreased and then increased,while the viscosity gradually decreased and the particles gradually became spherical.With the increase of Fe_(2)O_(3),the proportion of MGBs with particle size less than 10μm increased gradually.From the above results,it can be concluded that the addition of Fe_(2)O_(3) is conducive to the formation of MGBs and the reduction of particle size.

Preparation and Properties of Ni-plated Glass Beads/PVC Composite

Ni-plated glass beads（GB） was obtained by electroless plating, based on PVC adhesive, Niplated GB/PVC composite was prepared. Temperature insulation, fi re retardation and microwave absorption properties were tested, the results showed that the nickel coating was compact and continuous, Ni-plated GB/ PVC composite is a kind of excellent temperature insulated, fi re retardate and light-weight material, and especially for microwave absorption well; Refl ectivity was lower than-2 dB in the frequency range of 11-17 GHz.

Effect of surface treatment on rheological behaviors of glass bead/hydroxyl terminated polybutadiene suspensions

Surface treatment of glass bead(GB) was carried out by using γ-glycidoxypropyltrimethoxy silane(GPTES) and γ-methacryloxypropyltrimethoxy silane(MPTMS) as coupling agents,respectively.The steady viscosity and yield stress of the GB/hydroxyl terminated polybutadiene(HTPB) suspensions were determined by Brookfield R/S rheometer.The effect of surface treatment on the viscosity and yield stress of GB/HTPB suspension was investigated.The results indicate that the viscosity of the pristine GB/HTPB suspension increases with increasing GB,and the relationship between its viscosity and volume fraction of GB depends on the shear rate.The modification of GB by MPTMS changes the viscosity of the MPTMS@GB/HTPB suspension,and its viscosity is the minimum at the MPTMS dosage of 0.3 g per 1 g GB.Additionally,the modification of GB by MPTMS increases the yield stress of the GB/HTPB suspension,and its yield stress is the maximum at the MPTMS dosage of 0.1 g per 1 g GB.The GPTES modified GB/HTPB suspension behaves lower viscosity and weaker shear thinning than the MPTMS modified GB/HTPB suspension within the range of experimental shear rate.

PRELIMINARY STUDY ON RETRO-REFLECTIVE COATED PAPER BASED ON MICROGLASS BEADS

High-reflectivity micro-glass bead, as a kind of retro-reflective material, is widely used in reflective fabric or film and other reflective coatings. But it is rarely used in coated paper. The retro-reflective theory of micro-bead is described. Also the effect of size of micro-bead, dosage of binder and different color layers on reflective properties of coated paper are discussed in this article. The results show that its retro-reflective efficiency is good, equally to reflective fabric or film when the micro-glass bead is used in coated paper.

Study on Surface Modification of Glass Bead by a Block Copolymer Coupling Agent

A tri-block copolymer coupling agent polystyrene-block-poly(n-butyl-acrylate)-block-poly(γ-methacryloxypropylt rimethoxysilane)(PS-b-PnBA-b-PMPS)was synthesizedby atom transfer radical polymerization(ATRP),and its molecular structure was characterized by fourier-transform infrared spectra,hydrogen nuclear magnetic resonance and gel permeation chromatography.The glass bead was treated with the block copolymer coupling agent,and then studied by transmission electron microscopy.The result showed that strong interaction was formed between the block copolymer coupling agent and the surface of glass bead,and then the block of poly(n-butylacrylate)formed a layer of film on the surface.

Genetic transformation of Platymonas (Tetraselmis) subcordiformis (Prasinophyceae, Chlorophyta) using particle bombardment and glass-bead agitation

Platymonas (Tetraselmis) subcordiformis is a unicellular marine green alga. It was found to be very sensitive to the herbicide Basta through a sensitivity test indicating it could be employed as a selective agent. The bar gene is a practicable and selectable marker gene. The vector containing the expression cassette of the bar gene was transferred to P. subcordiformis by both particle bombardment and glass-bead agitation and transformants were then selected using Basta. Finally, Southern blotting analysis indicated that the bar gene had been successfully integrated into the nuclear genome of P. subcordiformis using both of the transgenic techniques, with the transformation efficiency of the glass-bead method being slightly higher than that of particle bombardment. This is the first report on stable transformation of P. subcordiformis, and will improve fundamental research and enlarge application of this alga.

表面活性剂对玻璃微珠镀银微观结构及性能影响

利用硅烷偶联剂KH792对小粒径玻璃微珠(GMs)表面进行修饰改性,以葡萄糖为还原剂,通过化学镀法制得玻璃微珠镀银(GMs@Ag)复合粒子,探讨了不同类型表面活性剂对样品物相、微观结构、外观及电性能的影响。将该复合粒子作为导电填料,制备柔性电磁屏蔽织物,对样品的电磁屏蔽性能进行了测试。结果表明:添加聚乙烯吡咯烷酮(PVP)和阿拉伯树胶(AG)复合表面活性剂制备的GMs@Ag镀层致密、均匀、连续,粉末电阻率值为12.4mΩ·cm,在其添加量为70%,在电磁波频率为30~1500MHz下,涂层的电磁屏蔽效能可达到40dB以上,有一定的应用前景。

汗液老化对玻璃微珠反光材料性能的影响

反光材料具有良好的夜间可视性,在夜间及视线较差的环境下给人们提供有效可靠的安全保障,被广泛应用于特殊作业服装等领域。为了科学评估反光布的安全防护作用,探讨汗液对玻璃微珠反光材料性能的影响,对反光材料分别进行1、5、10、20、25、30、40、50次酸碱汗液老化实验,对试样外观特征、色差、微观结构、逆反射系数进行实验与分析。结果表明:老化后试样有不同程度的玻璃微珠脱落、铝层溶出、表面盐结晶析出等现象,导致反光材料性能下降;试样的反光性能随酸碱汗液老化次数的增加先提升后下降,汗液老化次数大于5次,逆反射系数呈下降趋势,其中酸性汗液相比于碱性汗液对反光材料性能的影响更显著;经过酸性汗液老化50次,试样的逆反射系数下降了2.97%~12.86%。

不同冲击介质在机械镀锌中的运用及分析

通过改变机械镀锌工艺中的冲击介质条件,研究了玻璃珠、硅酸锆珠和氧化锆珠3种不同冲击介质在相同镀覆面积条件下对镀层质量的影响。从镀层表面形貌、镀层硬度、镀层结合强度和镀层耐腐蚀性能4个方面对镀层进行了分析。结果表明:以硅酸锆珠、氧化锆珠为冲击介质制备的试件表面光滑平整,镀层表面致密区增大。镀层的平均硬度值分别提高8.8、13.6 HV,镀层结合强度等级提升到0级,耐腐蚀性能提高。

低吸水率水性隔热保温涂料的制备及性能

[目的]随着水性隔热保温涂料在工业涂装领域的广泛应用,其吸水率较高引发的涂层隔热性能下降问题亟需解决。[方法]以苯丙乳液作为主要成膜物,以偶联剂表面改性的中空玻璃微珠作为隔热填料,以涂层的导热系数和吸水率作为主要性能指标,制备了一种低吸水率的水性隔热保温涂料。通过傅里叶变换红外光谱仪(FT-IR)对不同偶联剂处理的中空玻璃微珠进行了表征,通过扫描电子显微镜(SEM)考察了涂层的微观结构和形貌,测试了浸水前后涂层的导热系数、力学性能和粘结强度。[结果]铝酸酯偶联剂的改性效果比硅烷偶联剂好。当铝酸酯偶联剂改性中空玻璃微珠添加量为25%(质量分数)时,涂层的综合性能最优,24 h吸水率为9.32%,浸水168 h后的导热系数为0.1228 W/(m·K),拉伸强度为2.45 MPa,断裂伸长率为28.37%,拉拔法粘结强度为2.32 MPa。[结论]采用合适的偶联剂对中空玻璃微珠进行表面改性可有效改善隔热保温涂料体系中有机-无机界面的相容性,从而降低其吸水率,增强其力学性能。

有机硅/改性空心玻璃微珠复合材料的制备与性能研究

以缩合型有机硅为有机树脂基体,以改性空心玻璃微珠为无机填料,基于物理复合法制备出不同空心玻璃微珠含量的有机硅/改性空心玻璃微珠复合隔热材料。系统性研究其隔热机理、隔热性能、力学性能和热稳定性能,实现对复合隔热材料孔隙率和隔热性能的精准调控。研究结果表明,所制得的复合隔热材料的压缩强度最大值达到13.28 MPa,是纯有机硅材料的1.49倍,热导率最低为0.113 W/(m·K),比纯有机硅材料减小了37.91%。

广西越州故城遗址玻璃珠饰的科学研究

本研究利用能量色散型X射线荧光光谱分析、共聚焦激光拉曼光谱分析、光学相干层析成像、超景深光学显微观测等多种方法对广西越州故城遗址出土的印度-太平洋玻璃珠饰进行科技分析,获取了玻璃珠的化学成分、物相结构、内部物理结构、表面显微形貌等综合物理化学信息,确定了玻璃珠的玻璃体系、制作工艺(着色工艺、成形工艺)和产地来源,探讨了以丝绸之路为主线的国内发现魏晋南北朝时期印度-太平洋玻璃珠可能的输入路线。广西越州故城遗址发现的印度-太平洋玻璃珠为中外文明交流提供了新实物证据,对深入研究我国南北朝时期中外文明交流具有十分重要的学术价值和研究意义。

乌兹别克斯坦拜松市拉巴特墓地出土珠饰的分析研究

2017年—2018年度,中乌联合考古队在乌兹别克斯坦共和国拜松市拉巴特墓地进行了考古发掘,发掘墓葬94座,出土了丰富的遗迹遗物。考古学初步研究表明,该墓地为公元前2世纪末到公元2世纪的一处月氏文化墓地,文化因素丰富,为古代月氏文化面貌研究及北巴克特里亚地区公元前2世纪至公元2世纪的古代文化研究提供了重要的考古新资料。拉巴特墓地发掘中出土各类材质珠饰1 500余件,选取了其中典型人造硅酸盐质珠饰残样13件,采用超景深三维显微系统(OM)、能量色散型X射线荧光光谱(EDXRF)、扫描电子显微镜能谱分析(SEM-EDS)、激光拉曼光谱(Raman)等方法对其进行了科技分析,确定了这些人造硅酸盐质珠饰的材质属性和部分制作工艺相关信息,结合材质和工艺特点探讨了拉巴特墓地人造硅酸盐质珠饰可能的产地。结果表明,该遗址人造硅酸盐质珠饰包括富钠费昂斯、泡碱型钠钙玻璃、植物灰型钠钙玻璃、高镁钠钙玻璃、矿物碱型钠铝玻璃、植物灰型钠铝玻璃和钾玻璃等多种材质。其中,富钠费昂斯的产地与西亚有关;已分析出的六类玻璃产地涉及西亚、地中海周边、印度、巴基斯坦、中亚等多个地区。研究表明拉巴特墓地所处区域在公元前2世纪末期到公元2世纪文化面貌丰富,与西亚、地中海、南亚等地的经济贸易往来频繁、人群间文化互动丰富。

西藏阿里地区曲龙遗址出土珠饰的科学研究

曲龙遗址位于西藏阿里地区札达县,出土了公元前7~前5世纪的白色滑石珠以及公元1~4世纪的赤红色不透明玻璃珠。通过分析这两种珠饰的工艺、原料,本文认为玻璃珠与巴拉遗址等南亚北部的玻璃珠相似,滑石珠显示出与西喜马拉雅高山地区滑石珠的密切联系。这些发现反映出各个时期的曲龙遗址先民可能与南亚次大陆北部存在物质交换,通过象泉河等河谷地带将低海拔或临近高山地区的装饰品带入当地的生活中。结合西藏西部、新疆南缘、河西走廊同时期的玻璃珠,研究发现公元前1千纪下半叶后,南亚类型的玻璃珠开始频繁出现于阿里地区以及新疆南缘,南亚珠饰的传播半径扩大,西藏西部地区参与进印度河流域与新疆甚至黄河流域的物质文化交流互动中。

空心玻璃微珠在高性能保温涂料中的应用

通过对比不同种类的玻璃微珠,得到可以赋予涂料更低保温性能的玻璃微珠HL20;通过加入不同量的水分,得出了适量的水分不会对涂料性能造成不利影响,甚至还会在一定范围内对保温性能及粘接强度有利;通过不同玻璃微珠HL20用量的对比得出了较优的玻璃微珠添加量;通过HL20及HL25分别与不同量气凝胶浆体(固含22%左右)复配制备涂料的数据对比,最终得出HL20制备的保温涂料综合性价比要远远优于添加气凝胶浆的涂料;通过实验室较优配方与市场上现有涂料的性能对比,得出了实验室使用玻璃微珠HL20制备的保温涂料综合性能均优于市场配方,并且价格上要远远低于使用气凝胶制备的涂料A。

SiO_(2)气凝胶及其他功能填料对反射隔热涂料性能影响

为了提高SiO_(2)气凝胶反射隔热涂料的保温隔热性能,研究了亲水、疏水性SiO_(2)气凝胶的掺量对反射隔热涂料的太阳热反射率和隔热温差的影响,以及几种功能性填料的作用。结果表明:掺量1.5%的疏水SiO_(2)气凝胶制得的反射隔热涂料性能最好,其太阳热反射率达到了83.32%,隔热温差达到了31.6℃。掺量为9%的空心玻璃微珠所制的反射隔热涂料的反射率达到85.33%,隔热温差达到32.65℃,是其他功能性填料中表现最佳的一种填料。1.5%疏水SiO_(2)气凝胶和9%空心玻璃微珠复配制得的反射隔热涂料其导热系数为0.041 W·m^(-1)·K^(-1),比各自单独使用制得的反射隔热涂料的导热系数低30%~40%,表现出良好的保温隔热效果。

水性反射隔热型涂料的制备及性能影响因素探究

研究了反射隔热涂料中重要组分对其性能的影响规律。以纯丙乳胶作为成膜物,空心玻璃微珠和金红石型二氧化钛作为功能填料,在基本配方体系基础上,通过单一变量控制法研究了空心玻璃微珠、金红石型二氧化钛的尺寸及添加量等因素对反射隔热涂料透水及耐沾污性、太阳光反射性能和隔热性能的影响规律,并制备得到综合性能优异的水性反射隔热涂料。研究结果表明,反射隔热填料不仅影响涂层的太阳光反射和隔热性能,对于涂层的耐水和耐沾污性也有显著影响。