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101.
PP/POE/滑石粉三元复合材料的研究 总被引:5,自引:0,他引:5
研究了弹性体(POE)、滑石粉、偶联剂和填料处理方式对聚丙烯(PP)的力学性能、加工性能、结晶行为以及无机粒子在基体中分散形态的影响。结果表明,PP 2(K 7726)/POE(80/20)二元共混体系的综合性能较好;采用方式C(将两种偶联剂按1∶1的质量比,先加钛酸酯后加硅烷处理滑石粉)制得的PP 2/POE/T a lc(80/20/25)三元复合材料的力学性能比其它两种方式有显著提高。偏光显微镜(PLM)研究表明,方式C处理的滑石粉在体系中分散性最好;扫描电镜(SEM)显示,三元复合体系由PP 2/POE耗能少的空洞化断裂方式向耗能多的剪切屈服方式转变;DSC表明,采用方式C处理的滑石粉对聚丙烯的成核作用减弱。 相似文献
102.
Lin Zhu Xinhua Xu Fengjuan Wang Na Song Jing Sheng 《Materials Science and Engineering: A》2008,494(1-2):449
Poly(ethylene-co-octene) (POE) was mixed into polypropylene (PP) by an internal mixer, which was installed on on-line small-angle laser light scattering (SALLS) device. A new parameter called the thickness (d) of transition layer was introduced to describe the compatibility of PP/POE blends in both dynamic and static states. Using the correlation distance, ac (it was indicative of the dimension of the dispersed phase pellets), d was calculated for the PP/POE blends based on the SALLS theory. The results indicated that the average values of d increased with increasing concentration of dispersed phase and had a maximum value at 40/60(PP/POE) for the blends. And the values of d showed much more violent fluctuation and were much larger at the early stage of mixing, but at a later stage d leveled off and approached to steady state. In addition, the relationships between the thickness of transition layer and mechanical properties were studied. It showed that the notched Izod impact strength and the average values of d of PP/POE blends increased with increasing of POE concentration, while the Young's modulus and flexural modulus decreased. The results indicated that SALLS method was an effective method to deal with diffuse transition layer of PP/POE blends and d was indeed a valid parameter to describe compatibility. 相似文献
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ABSTRACTRaymond J. Cole’s body of work, spanning sustainable design, system complexity and human agency, has encouraged researchers to reconceptualize the notions of comfort and building performance. However, methods for predicting energy use and assessing environmental performance have remained predominantly within a reductionist approach common to physics and engineering. The recognition that building performance is characterized by interactive adaptivity and co-evolution of the physical with the social has not been matched by the generation of new methods. Although social practice theories that articulate the socio-technical nature of the built environment have been increasingly appropriated to understand occupants’ role in performance, the challenge of studying buildings as complex socio-technical systems remains. This methodological paper discusses the application of the case study method (CSM) to the study of 10 retrofit projects selected from the Retrofit for the Future (RfF) Programme in UK between 2011 and 2012. Guided by Greene’s framework for methodological discourse, the epistemic regime is articulated under four headings: philosophical assumptions, investigative logics, guidelines for practice and contribution to system perspective. The discussion of these domains highlights the fecundity of CSM in providing a more nuanced understanding of the interaction between social and technical systems in performance. 相似文献
106.
国内开展建筑使用后评估的必要性研究 总被引:7,自引:0,他引:7
建筑使用后评估关注的是建成使用一段时间后建筑物的性能和服务于业主/用户的满意程度,它连接了建筑物的规划设计和使用阶段,为后续建筑的设计提供参考,提高建筑业用户的满意度。本文介绍了建筑使用后评估在国外的发展历史和近期的实践活动,提出了建筑使用后评估在国内开展的必要性,也提出了在国内开展的难点,可作为政府和相关企业的参考。 相似文献
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The objective of this work was to investigate the effect of elastomer polarity on phase structure and mechanical properties of PP nanocomposites. The nonpolar and polar elastomers studied were polyethylene octene (POE) and polyethylene octene grafted maleic anhydride (POEgMAH), respectively. The results from mechanical studies showed that the POEgMAH-toughened polypropylene nanocomposites have higher Izod impact strength but lower tensile and flexural properties than the unmaleated ones. X-ray diffraction (XRD) was used to characterize the formation of nanocomposites. XRD studies revealed that intercalated rubber-toughened PP nanocomposites (RTPPNC) had been successfully prepared where the macromolecule segments PP were intercalated into the interlayer space of organoclay. XRD also indicated that the incorporation of polar POEgMAH elastomers into PP nanocomposites contribute to a better intercalation effect and formed a more exfoliated combinations structure compared to POE. Scanning electron microscope (SEM) was used for the investigation of the phase morphology and rubber particle size and particle-size distribution. SEM study revealed a two-phase morphology where POE as droplets dispersed finely and uniformly in the PP matrix. The POEgMAH-toughened PP nanocomposites shows a much finer dispersion of elastomer particles than POE-toughened PP nanocomposites. 相似文献
109.
广州西关作为旧城区的空间核心及城市文化代表,其更新改造问题一直是各界关注的焦点。谊文以经过一定程度整治后的广州西关社区的典型公共街角空间为研究对象,基于当地居民的日常生活视角,综合利用问卷调查、观察和访谈的方法对目标空间环境进行使用后评价(Post occupancy Evaluation,POE),深入分析影响当地居民环境取向和主观评价的内在因素,剖析环境更新与居民生活空间需求之间的关系,总结环境更新的正反经验。以期为进一步的城市公共环境的整治积累第一手的反馈数据。 相似文献
110.
以过氧化二异丙苯(DCP)作为引发剂,使用哈克(HAAKE)流变仪研究了乙烯基三乙氧基硅烷(VTES)接枝交联不同型号的聚烯烃弹性体(POE)(TAFMER DF610、Vistamaxx 6202、Koattro KT-MR-05)的反应规律。结果表明,VTES以化学键接枝到POE分子链上。加工过程中扭矩变化和接枝交联的反应程度与POE的种类有直接关系,其中,DF610更容易预交联,接枝率较高;而Vistamaxx 6202和KT-MR-05在反应过程中产生降解,接枝率较低。对产品凝胶含量影响因素进行方差分析表明,水解前对凝胶含量影响严重的是DCP的含量,而水解后硅烷含量的变化对凝胶含量影响显著。 相似文献