基于生命周期模型的木塑复合材料研究分析

以加速老化为手段,考察氙灯照射和冻融循环对高密度聚乙烯(HDPE)/稻糠粉和HDPE/秸秆粉两种木塑复合材料弯曲强度的影响。结果显示,同等条件下,HDPE/秸秆粉木塑复合材料的弯曲强度显著大于HDPE/稻糠粉木塑复合材料。经过氙灯照射和冻融循环后,两种木塑复合材料的弯曲强度均下降,且它们的弯曲强度下降程度随着氙灯照射时间的增加而增加,随着冻融温差的增加而增加。无重复双因素方差分析结果显示,氙灯老化时间和冻融循环温度对两种木塑复合材料的弯曲强度影响均非常显著(p0.05,这里p表示显著性差异水平)。     

HDPE基木塑复合材料的洁丽香菇腐朽研究

研究了褐腐真菌——洁丽香菇对不同纤维含量及添加不同抗菌防腐剂的HDPE基木粉及竹粉填充的复合材料的腐朽情况,观察了腐朽对材料质量及吸水性能的影响。结果表明,在洁丽香菇处理12周后,HDPE/木粉及HDPE/竹粉复合材料均出现了质量损失,且损失随材料中纤维含量的增加而增加,但抗菌防腐剂的加入,可明显提高木塑复合材料对腐朽真菌的抗性,减少其质量损失;同时,腐朽显著增加了材料的吸水性能,使其吸水率增加;木塑材料的吸水率还受纤维含量及吸水温度的影响。     

两种不同基体木塑复合材料的制备及性能研究

以稻糠代替木粉,分别制备了高密度聚乙烯(HDPE)基体和聚甲醛(POM)基体木塑复合材料。结果表明稻糠含量小于50%时,这两种木塑复合材料均具有良好的加工流动性;稻糠含量从0增加到50%,拉伸强度和冲击强度下降,热变形温度提高;稻糠含量40%时,木塑复合材料韧性相对于单纯树脂下降最小;稻糠含量在40%时,耐热性能改善效果最为明显。综合各因素对木塑复合材料性能的影响,稻糠填充量选在40%较合适。POM基体木塑复合材料在拉伸性能、弯曲性能和耐热性能方面优于HDPE基体木塑复合材料,但在无缺口冲击性能方面HDPE基体木塑复合材料优于POM基体木塑复合材料。     

塑料基体中MAPE/HDPE比例对木塑复合材料力学性能的影响

以高密度聚乙烯(HDPE)和马来酸酐接枝聚乙烯(MAPE)共混物为塑料基体,以木粉为填料,用注塑成型法制备木塑复合材料,研究MAPE/HDPE质量比变化对塑料基体和木塑复合材料力学性能的影响.结果表明:MAPE/HDPE比变化对MAPE/HDPE共混形成的塑料基体强度基本没有影响,但对由该共混物所制得的木塑复合材料的强度影响显著;在相同的木粉含量下,保持配方中MAPE和HDPE的总含量不变,木塑复合材料的拉伸强度随MAPE/HDPE比率增大先迅速增加,然后趋于平缓.冲击强度随MAPE/HDPE比增大逐渐减小.     

防霉剂对木塑复合材料吸水性能的影响研究

研究了防霉剂对木塑材料自身吸水性能的影响,以竹粉/高密度聚乙烯(HDPE)、木粉/HDPE为供试复合材料,通过向其中添加一定量的ZB-2335、WPC-GUARD及ZD-29E、ZD-4E四种防霉剂,测试不同防霉剂对木塑材料吸水性能的影响.结果表明:无论是在室温还是在60℃条件下,四种防霉剂均对竹粉/HDPE、木粉/HDPE复合材料的吸水性能无显著影响.向竹粉/HDPE、木粉/HDPE复合材料中加入不同用量的ZD-29E防霉剂,测试了ZD-29E防霉剂用量对木塑材料吸水性能的影响,结果表明:无论是在室温还是60℃条件下,不同用量ZD-29E防霉剂的加入,对供试木塑材料的吸水性能无显著影响.     

不同温度条件下废弃牛奶盒/聚乙烯复合材料性能的研究

研究了温度对于废弃牛奶盒/聚乙烯复合材料性能的影响。结果表明:(1)废弃牛奶盒/聚乙烯复合材料在52、85、-29、-40℃四种典型的温度环境中处理15 d后,各个方向的尺寸变化率符合热胀冷缩的规律,且各个方向的尺寸变化率呈现出典型的各项异性特征,其中厚度方向的尺寸变化率最大;(2)材料在52、85℃下处理一个月后,弹性模量和弯曲强度都降低了很多,且随着温度的升高,降低的幅度也有所增加,85℃下材料几乎丧失了弯曲强度;在-29、-40℃下处理一个月后,弹性模量和弯曲强度都呈现出了增大的趋势,且随着温度的降低,增大的幅度也在变大;(3)材料经历不同的温度段的冻融循环后,弹性模量和弯曲强度降低的幅度随着温度差的增加而增加;随着循环次数的增加而增加;与经历单纯的高温或者低温的材料的弹性模量和弯曲强度保留率进行对比,冻融循环对材料的弯曲性能影响更大。     

建筑模板用不同配比高密度聚乙烯/木塑材料性能表征

选择竹粉与高密度聚乙烯(HDPE)作为原料,通过加入复合阻燃剂的方法并对其实施共混挤出制备得到木塑材料,之后对该材料的吸水性、力学强度与阻燃性开展实验分析。结果表明,随木塑材料的竹粉添加量上升,复合材料的拉伸强度不断增大,伸长率减小。将HDPE、竹粉与马来酸酐接枝聚乙烯(PE-g-MAH)质量比设定在50/45/5的比例时,材料获得良好的综合力学性能。当木粉的添加量上升后,HDPE/木塑材料获得了更高的吸水率。当PE-gMAH添加量上升,材料力学性能提高。复合型阻燃剂不会使该材料的力学性能发生变化。在没有加入阻燃剂的情况下,测试HDPE/竹粉材料的极限氧指数(LOI)为21. 26%。当膨胀石墨的添加量增加后,HDPE/木塑材料的LOI也明显升高。     

白腐菌对木塑复合材料质量及吸水性能的影响研究

对不同纤维含量及添加不同抗菌防腐剂木粉/HDPE及竹粉/HDPE复合材料的白腐菌云芝腐朽进行了研究,并在腐朽试验后,对材料的吸水性能也进行了探索,以明确白腐真菌对木粉/HDPE及竹粉/HDPE复合材料质量及吸水性能有无影响。研究结果显示,在云芝腐朽后,竹粉/HDPE及木粉/HDPE复合材料均出现了质量损失,且损失随材料中纤维含量的增加而增加,但抗菌防腐剂的加入,可明显提高WPC试样对腐朽真菌的抗性,减轻其质量损失;而试样的吸水率则受材料腐朽、纤维含量及吸水温度的共同影响。     

交联聚乙烯回收料增韧高密度聚乙烯

采用机械粉碎方法制备了交联聚乙烯回收料(RXLPE),并使用RXLPE填充高密度聚乙烯(HDPE),对RXLPE/HDPE复合材料的热性能、注塑制品力学性能和常温下的晶体形态进行了研究。结果表明:RXLPE填充HDPE后,材料的结晶峰值温度升高,由118℃提高到121℃,说明RXLPE具有明显的异相成核作用;随着RXLPE含量的增加,材料结晶度明显下降。RXLPE/HDPE复合材料注塑成型制品的冲击强度随着回收料含量的增加而增加,当RXLPE和HDPE比例为50∶50时,材料的冲击强度约为纯HDPE的3倍,而弯曲模量略有下降。常温下偏光显微镜结果表明,制品晶体粒径随着RXLPE含量的增加而下降,RXLPE具有细化晶粒的作用,同时也是引起注塑制品冲击强度增加的主要原因。     

木塑复合材料弯曲振动弹性模量优势因素分析

以木塑复合材料加工实验为先导,利用弯曲振动方法得到不同工艺条件的木塑复合材料动态弹性模量。选取木粉含量、造粒温度、螺杆转速、偶联剂含量作为影响力学性能指标的主要因素,通过灰色关联分析方法分析不同加工因素对材料力学性能的影响程度。结果表明,木粉含量对木塑复合材料料的弹性模量有显著影响,其次是造粒温度。材料的动态弹性模量随木粉含量的增加而增大;造粒温度在130～140℃范围内,动态弹性模量随温度的升高而增大;在140～150℃时,动态弹性模量呈下降趋势。     

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%.