聚砜改性酚醛树脂玻纤增强模塑料的热老化研究

研究了聚砜改性酚醛树脂玻纤增强模塑料在200℃、230℃的热老化过程中的力学性能、电学性能的变化情况。结果表明，热老化后，材料的性能(弯曲强度除外)虽有所下降，但仍能满足使用要求，说明此种模塑料具有良好的热稳定性，能在200℃下长期使用。     

玻璃纤维增强聚酰胺66耐冷却液性能研究

从冷却液对材料力学性能影响的角度出发，研究了玻璃纤维增强聚酰胺材料在冷却液中的老化作用。选用质量分数为30 %的玻璃纤维增强聚酰胺66（PA66/30 %GF）开展冷却液热老化试验（1008 h，125 ℃），研究在冷却液加速热老化过程各阶段材料的弯曲强度和冲击性能，并从微观结构的变化来分析其机理。结果表明，杜邦和索尔维的PA66/30 %GF经历1008 h老化后，弯曲强度大于70 MPa，性能保持率超过25 %，适宜在冷却液环境中长期使用。     

玉米秸秆纤维-氨基树脂模塑料的制备与性能研究

以玉米秸秆纤维为增强材料,氨基树脂为基体聚合物,制备了玉米秸秆纤维-氨基树脂模塑料。研究了玉米秸秆纤维浆料质量分数对模塑料的弯曲强度和冲击强度的影响。采用电子扫描显微镜(SEM)表征玉米秸秆纤维和氨基树脂的界面结合性能,并利用动态机械热分析(DMA)和热重分析(TG)分析模塑料的动态力学性能和热稳定性。研究表明,当玉米秸秆纤维浆料质量分数为31%时,氨基树脂模塑料的力学性能优异,弯曲强度为60.41 MPa,冲击强度为1.81 kJ/m²,模塑料的储能模量较高,性能较优;玉米秸秆纤维与氨基树脂的相容性稍差;模塑料在68.8~114.3℃时失重率仅为0.5%~2%,在246.0~345.2℃时失重率较高,达到26%,玉米秸秆纤维质量分数对模塑料的热稳定性影响不明显。     

废弃环氧模塑料填充聚氯乙烯的研究

用废弃环氧模塑料粉作为填料,采用模压成型的方法制备了聚氯乙烯（PVC）/废弃环氧模塑料复合材料,研究了废弃环氧模塑料粉的组成和性质及其与PVC的界面黏结情况,分别考察了温度和废弃环氧模塑料粉含量对复合材料力学性能和动态力学性能的影响。结果表明,废弃环氧模塑料粉具有一定的活性,能与极性树脂PVC发生作用而产生界面接枝;在模压温度为200 ℃,废弃环氧模塑料粉含量为60 %（质量分数,下同）时,复合材料的拉伸强度为32.13 MPa,弯曲强度和冲击强度分别为60.70 MPa和4.68 kJ/m2,基本可满足相关产品的要求;随着废弃环氧模塑料粉含量的增加,复合材料的储能模量提高,损耗峰向高温方向移动,且损耗峰形先变宽后变窄。     

不饱和聚酯树脂／大麻纤维复合材料的热氧老化

采用模压工艺制备不饱和聚酯(UP)树脂/大麻纤维复合材料,研究了105℃下热氧老化600h前后复合材料力学性能的变化;采用傅立叶变换红外光谱仪(FTIR)对老化前后复合材料的结构进行对比分析,并通过SEM技术观察复合材料的断面形貌.结果表明,偶联剂KH570处理对复合材料力学性能的总体改善效果最佳.老化600h后,偶联剂处理复合材料具有的最佳力学性能如拉伸强度、拉伸模量、弯曲强度、弯曲模量及冲击强度分别为19.06MPa、5.78GPa、52.988MPa、1.01GPa和3.881kJ/m2.红外分析显示,偶联剂处理得到的复合材料在老化前后的红外图形变化不明显,有些吸收峰甚至得到了加强.SEM结果表明,老化600h后,偶联剂处理的复合材料中纤维仍能较均匀地分散在树脂基体中,两者间的界面粘结良好.     

聚砜、复合增韧剂改性酚醛模塑料的耐油性研究

通过采用聚砜、复合增韧剂对酚醛模塑料进行改性，成功制得了一种耐油型酚醛模塑料。分别在200℃和170℃的仪表油中浸泡24h和100h，测其力学性能和电绝缘性能，结果表明，除垂直纤维方向的压缩强度外，各项性能保持率均达95％以上。采用SEM等手段对改性模塑料进行研究和分析，并同国外同类材料进行比较，发现聚砜、复合增韧剂改性酚醛模塑料具有优异的力学性能、电绝缘性能和耐滑油性能。     

聚砜、复合增韧剂改性酚醛模塑料的耐油性研究

通过采用聚砜、复合增韧剂对酚醛模塑料的界面进行改性，成功地制得了一种耐油型酚醛模塑料。分别在200℃和170℃的滑油中浸24h和100h，测其力学性能和电绝缘性能，除垂直纤维方向的压缩强度外，各项性能保持率均达95％以上。采用SEM等手段对改性模塑料进行研究和分析，并同国外同类材料进行比较分析，发现聚砜、复合增韧剂改性酚醛模塑料具有优异的力学性能、电绝缘性能和耐滑油性能，是国防用理想材料。     

木粉增强酚醛模塑料制件的后固化行为研究

利用动态力学分析（DMA）技术考察了后固化对木粉增强酚醛模塑料制件固化性能的影响。研究发现，随着后固化时问的增加，材料力学损耗（tanδ）的峰形变窄、峰值降低，储存模量提高。表明后固化进一步提高了酚醛模塑料制件的交联密度和交联结构的均一性。经后固化处理24h后，材料的玻璃化转变温度（Tg）和热变形温度分别提高了19．5℃和25℃，达到252．63℃和205℃，材料的冲击强度降低，弯曲强度在后固化进程中出现最大值，材料的弯曲模量升高，表面绝缘电阻从2．5×10^9Ω增加到4．8×10^12Ω，后固化处理增加了木粉及其增强材料的耐水性能，但也造成了一定的质量损失。     

石英纤维增强聚三唑树脂复合材料性能研究

本文研究了石英纤维增强的聚三唑树脂复合材料的固化行为、热性能、介电性能及力学性能。复合材料能够在80℃下固化成型,经过120℃/2h+150℃/2h+180℃/2h+200℃/2h+250℃/2h后处理,固化完全,玻璃化转变温度T g高达230℃,介电常数为3.8。力学性能随后处理温度升高而上升,至250℃时,弯曲强度和层间剪切强度分别为795MPa和61MPa,180℃时弯曲强度保留率达到59%。     

星型支化尼龙进气歧管专用材料的研究

利用星型支化剂处理尼龙和短玻璃纤维,制备星型结构尼龙的进气歧管材料。星型尼龙中,分子链之间形成空间网状结构,大大地提高材料的物理性能和爆裂强度。星型尼龙,在150℃老化,其拉伸强度经过500 h老化仍可达164.83 MPa;弯曲模量和缺口冲击强度在经历近400 h热老化后反而会逐渐提高,这是因为星型尼龙材料在老化过程中发生固相交联。同时,星型尼龙材料,具有优良加工流动性,提高表面光洁度,提高生产效率,降低能源消耗。     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

氢气纯度分析方法准确性的探讨

ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l／3为氧气,2／3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中：A一混…     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

HEASUREHENT OF INSTANTANEOUS RATES OF LOSS OF VOIATILE COMPOUNDS DURING DRYING OF DROPS

A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.

Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology.     

用两个形状指数表征粉煤灰颗粒形貌的研究

引用两个形状指数表征颗粒形状的概念,即先将颗粒形状近似为椭圆,再将椭圆图像分离:以圆为基准的颗粒宏观形状指数δ;以光滑椭圆为基准的颗粒轮廓凹凸度,即微观形状指数ζ。分析和发展了近似椭圆模型。并运用图像分析仪对粉煤灰、水泥样品进行实验。结果表明,粉煤灰颗粒的两个形状指数δ和ζ都大于水泥颗粒。证明粉煤灰颗粒的球形度、表面光滑度优于水泥,而且,随着粒径增大,δ和ζ呈下降趋势,表明磨制颗粒越粗。(?)粒形状越不规则。文中还运用近似椭圆模型再现了颗粒的模拟图像。     

典型煤碳燃烧特性研究和数值模拟

本文以三种典型煤的碳燃烧为研究对象，分别采用简单一维沉降燃烧方式和等温加热燃烧方式，实验研究了煤在快速加热条件下，其碳的初期和中，后期燃烧过程。以实验为基础，建立了煤的碳燃烧模型，变工况数值模拟了煤的碳燃烧过程，揭示了煤不同条件下的单颗粒碳燃烧特性。     

茶多酚提取方法进展

本文综述了国内外现有茶多酚提取方法的现状以及近期的研究进展，并对其优缺点进行了评价。这将有助于中低档茶的综合利用和茶多酚的进一步开发应用。     

卫生陶瓷烧成用窑炉发展之我见

归纳了当今卫生陶瓷工业的发展现状和水平 ,对窑炉产业提出了的新要求 ,分析了某一新型窑炉的特点 ,对发展我国陶瓷窑炉产业提出了建议     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.