PUE/微米SiO2复合材料抗冲蚀磨损性能研究

采用预聚体法制备了聚氨酯弹性体(PUE)/微米SiO2复合材料,通过硅烷偶联剂KH-550对微米SiO2表面改性以及超声波分散的方法来提高微米SiO2在PUE基体中的分散性,并研究了表面处理后微米SiO2对PUE/微米SiO2复合材料的磨损性能的影响.结果表明,经过表面处理微米SiO2的用量对复合材料的磨损性能影响较大...     

改性纳米碳化硅/聚氨酯弹性体复合材料的制备

采用KH-560与KH-550反应得到新的硅烷偶联剂改性纳米碳化硅(SiC);再以2,4-甲苯二异氰酸酯(TDI)、聚氧化丙烯醚二醇(PPG2000)为原料合成预聚体,改性纳米SiC为填料、3,3’-二氯-4,4’-二氨基二苯甲烷(MOCA)为扩链剂,制备了改性纳米SiC/聚氨酯弹性体(PUE)复合材料。讨论了改性前后的纳米SiC添加量对复合材料的力学性能、耐磨性能和热稳定性的影响,并用扫描电镜分析了改性前后的纳米SiC在基体中的分散性。结果表明,改性后的纳米SiC在基体中的分散性优于纳米SiC,当改性纳米SiC质量分数为9%时,改性纳米SiC/PUE复合材料的力学性能达到最佳,耐磨性能明显改善,热失重温度提高了33℃。     

一种大分子改性剂对纳米SiO2的改性及其在PU中的应用

采用自制的大分子表面改性剂(MAA)m-(BA)n-NCO对纳米SiO2进行表面改性,对改性前后的纳米SiO2进行FTIR、TGA、粒径分析表征.结果表明,大分子改性剂和纳米SiO2的表面发生化学键合,有效地阻止了纳米SiO2的团聚.用改性后的纳米SiO2制备了纳米SiO2/聚氨酯(PU)复合材料,SEM观察到纳米SiO2颗粒在PU中分散良好,XRD检测表明纳米SiO2阻碍了PU分子硬链段有序排列.力学性能检测显示纳米复合材料的力学性能有明显提高,当SiO2的用量为3％时,复合材料的断裂伸长率和拉伸强度均达到最大值,分别为458％和80.4 MPa.     

LLDPE／纳米SiO2复合材料的制备与性能研究

利用超声波分散，偶联剂对纳米SiO2进行了表面改性，用共混法制备了LLDPE/纳米SiO2复合材料，系统研究了该种新型复合材料的静态，动态力学性能和红外吸收性能，并与球磨机分散，偶联剂表面处理的纳米SiO2制备的LLDPE/纳米SiO2复合材料进行了对比。结果表明，纳米SiO2对LLDPE具有一定的增强，增韧作用；复合材料的贮能模量和损耗模量随SiO2含量的增加而增大，阻尼在-15-30℃范围内逐渐降低；复合材料的红外吸收能力较LLDPE明显提高，不同的分散，表面处理方法对纳米SiO2在基体中的分散性能影响不同。仅填加3份纳米SiO2时，常规分散，表面处理方法比基体树脂的红外吸收性能提高了42.5%。超声波分散，偶联剂表面处理方法比基体树脂提高了106.7%。     

聚氨酯弹性体/纳米二氧化硅协同改性聚氯乙烯及其力学性能

用聚氨酯(PU)弹性体/纳米SiO2复合材料协同改性聚氯乙烯(PVC),用反应挤出一步法成型工艺制备了PU弹性体/纳米SiO2/PVC复合材料,对挤出速率和温度进行了考察,并对复合材料力学性能的影响因素进行了研究。结果表明,制备该复合材料的最佳工艺条件是螺杆转速为40～50r/min、挤出机均化段温度为180～190℃;用分散于液化二异氰酸酯中的纳米SiO2制备的复合材料的性能优于用分散于聚醚二元醇中的纳米SiO2;PU弹性体和纳米SiO2能协同增韧PVC,两者质量比为5/1时增韧改性的效果最佳。当PU弹性体/纳米SiO2/PVC(质量比)为5/1/20时,复合材料的综合力学性能最优,冲击强度达到45.6kJ/m2,拉伸强度为50.3MPa。     

多壁碳纳米管改性聚氨酯弹性体的研究

采用多壁碳纳米管(MWCNT)对聚氨酯弹性体(PUE)进行改性,研究MWCNT用量、分散方式以及偶联剂表面处理等因素对PUE性能的影响.结果表明,MWCNT在PU基体中为部分纳米级分散;随着MWCNT用量的增大,PUE的100%定伸应力和拉伸强度呈现先减小后增大再减小的趋势,而拉断伸长率呈现先增大后减小的趋势.动态力学性能分析结果表明,PUE的tanδ时随着MwcNT用量的增大而减小,弹性提高,采用偶联剂对MWCNT进行表面处理后,MWCNT与PU基体间的相互作用有一定提高,但团聚现象增加.     

β成核剂和纳米SiO_2复合改性PP/POE复合材料研究

研究了纳米SiO2和β成核剂对PP/POE复合材料力学性能的影响,并用广角X射线衍射仪(WAXD)对其进行了表征。结果表明:纳米SiO2的加料方式影响PP/POE复合材料的力学性能,先将PP和纳米SiO2共混挤出,再与POE共混制备得到的复合材料冲击强度最高。当纳米SiO2含量为4%时,PP/POE/纳米SiO2复合材料的综合力学性能最好。在PP/POE/纳米SiO2复合体系中的加入β成核剂后,复合材料的拉伸强度和弯曲强度下降,而韧性进一步提高,当β成核剂含量为0.4%时,复合材料的缺口冲击强度和断裂伸长率达到最大值,拉伸强度也明显提高。XRD表明,β成核剂在纳米SiO2改性PP/POE复合体系中能显著诱导β晶的生成。     

CE/纳米SiO2复合材料的改性研究

利用纳米SiO2对氰酸酯树脂(CE)进行改性。结果表明,适量的纳米SiO2可提高CE/纳米SiO2复合材料的冲击强度和弯曲强度;选用不同分子尺寸的偶联剂KH-560和SCA-3对纳米SiO2进行表面处理,扫描电镜(SEM)表明,纳米SiO2经偶联剂处理后CE/纳米SiO2复合材料的静态力学性能、动态力学性能都得到了不同程度的提高,特别是经SCA-3处理后的效果更加明显,偶联剂的加入改善了纳米SiO2在CE中的分散状态,使纳米SiO2与CE之间的界面结合强度进一步提高。     

偶联剂处理纳米SiO2对尼龙1010力学与摩擦学性能的影响

用A171和KH550 2种硅烷偶联剂对纳米SiO2进行分散处理,然后用注射成型法制备了纳米SiO2/尼龙1010复合材料。研究了改性处理纳米SiO2对尼龙1010复合材料的结晶性能、力学性能以及摩擦学性能的影响。结果表明:纳米SiO2表面的改性处理均使尼龙1010基体的结晶度降低,而拉伸强度、硬度和耐磨性提高。A171处理纳米SiO2/尼龙1010复合材料的断裂伸长率大于纯尼龙1010。改性处理纳米SiO2使尼龙1010复合材料的摩擦因数降低。     

丙烯酸酯类聚氨酯/SiO2纳米复合材料制备及性能研究

用原位聚合法制备丙烯酸酯类聚氨酯/SiO2纳米复合材料,通过透射电子显微镜研究了纳米SiO2在基体中的分散情况,并对材料的力学性能和光学性能进行了研究。结果表明,纳米SiO2在基体中分散很好;当纳米SiO2的质量分数为1.5%时,复合材料的综合力学性能最佳,其拉伸强度、断裂伸长率和冲击强度分别为34.20MPa、56.15%和81.52kJ/m2,与纯丙烯酸酯类聚氨酯相比分别提高了52.75%、81.19%和149%;且该复合材料的透光率在80%以上。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

三种煤样燃烧热的测定

本文通过三个厂家提供的三种煤样燃烧热的测定,由测定结果综合得出3号煤样燃烧最完全、燃烧热也最大,是三个煤样中最好的一种。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

我国聚碳酸酯工业发展概况

介绍我国聚碳酸酯生产能力和消费需求,对聚碳酸酯在信息工业中的应用作了简短介绍     

小议汽车涂装工艺设计对涂装成本的影响

论述了涂装工艺设计对涂装设备投资、涂装生产成本的影响。     

Effect of degree of deacetylation of chitosan on the kinetics of ultrasonic degradation of chitosan

The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003     

Measurement of the gradient of viscosity with composition of mixtures of non-ideal gases

A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%.