Role of heat transfer and thermal conductivity in the crystallization behavior of polypropylene‐containing additives: A phenomenological model

The thermal conductivity of a filler and the thermal conductivity of a composite made from that filler influence the heat‐transfer process during melt processing. The heat‐transfer process from the melt to the mold wall becomes an important factor in developing the skin–core morphology. These aspects were examined in this study. The thermal conductivity of polypropylene–filler composites was estimated with a standard model for various fillers such as calcium carbonate, talc, silica, wollastonite, mica, and carbon fibers. The rate of cooling under given conditions, including the melting temperature, mold wall temperature, mass of the composite, and filler content, was estimated with standard heat‐transfer equations. The time to attain the crystallization temperature for polypropylene was evaluated with a regression method with differential temperature steps. The crystallization curves were experimentally determined for the different fillers, and from them, the induction period for the onset of crystallization was estimated. These observations were correlated with the expected trends from the aforementioned formalism. The excellent fit of the curves showed that in all these cases, the thermal conductivity of the filler and composite played a dominant role in controlling the onset of the crystallization process. However, the nucleation effects became important in the later stages after the crystallization temperature was attained. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2994–2999, 2003     

Effect of sodium monofluorophosphate treatment on microstructure and frost salt scaling durability of slag cement paste

Sodium-monofluorophosphate (Na-MFP) is currently in use as a surface applied corrosion inhibitor in the concrete industry. Its basic mechanism is to protect the passive layer of the reinforcement steel against disruption due to carbonation. Carbonation is known as the most detrimental environmental effect on blast furnace slag cement (BFSC) concrete with respect to frost salt scaling. In this paper the effect of Na-MFP on the microstructure and frost salt scaling resistance of carbonated BFSC paste is presented. The results of electron microscopy, mercury intrusion porosimetry (MIP) and X-ray diffraction (XRD) are discussed. It is found that the treatment modifies the microstructure and improves the resistance of carbonated BFSC paste against frost salt attack.     

PET/MFMB复合材料的力学性能、热性能的研究

用力学性能测定、DSC和熔体流动速率（MFR）测定法研究聚对苯二甲酸乙二酯／多功能母料（PET／MFMB）复合材料的力学性能和热性能。结果表明，当MFMB的含量为22％时，PET／MFMB复合材料的冲击强度、断裂伸长率分别出现极大值；复合材料中PET、PP的熔点比纯PET、纯PP的稍有降低，当PET／MFMB＝78／22时降低的幅度稍大；复合材料的MFR在PET／MFMB＝78／22时出现转变点。     

过磷酸钙折流混合器的改进

由于绿原化工有限公司过磷酸钙装置生产能力由 6 70 t/ d(实物量 )提高到 84 0 t/ d,折流混合器负荷增大 ,出现折流环磨损加快等问题。采用若干技改措施 :扩大折流环内径、改变折流混合器喷射方向、采用新材料制作折流环 ,使折流混合器能满足 84 0 t/ d过磷酸钙生产的需要     

用RAP法引上技术生长KCL晶体

用RAP法(reactivo atmosphere process)处理KCl熔体,在不改变生长气氛和RAP继续处理的情况下,提拉生长KCl晶体,以解决高纯、大尺寸、生长速度快、成品率高和有较大经济效益的问题。     

Synthesis of tertiary poly(amido-amine)s with amido- and amino-groups randomly arranged along the macromolecular chain

A new synthesis of poly(amido-amine)s from bis (secondary amine)s and acryloyl chloride has been studied, leading to polymers in which the amido- and amino-groups are randomly arranged along the macromolecular chain. A poly(amido-amine) based on piperazine, chosen as the mother compound, has been fully characterized by ¹³C n.m.r. as well as by identification and quantitative evaluation of its hydrolysis products.     

新型植物杀菌剂--苯并噻二唑类植物抗病诱导剂

植物抗病诱导剂是近年来发现的一种新型植物杀菌剂，苯并噻二唑类(BTH)就是其中重要的一类。对近年来BTH研究情况作一简要综述。     

茂金属乙烯/苯乙烯假无规共聚物(ESI)的研究进展

乙烯／苯乙烯假无规共聚物（ESI）是一类新型的茂金属聚合物，通常苯乙烯质量分数可达80％，随苯乙烯的质量分数增加，ESI由半晶态的弹性体材料过渡到非晶态的热塑性塑料，笔者综述了近年来国外茂金属乙烯－苯乙烯假无规共聚物（ESI）研究与开发的新进展，重点介绍了ESI的物理性能，合成工艺，共混性能，填充性能，膜塑性能及发泡性能，并论述了ESI的应用现状和发展趋势。     

双－（p－N，N－二甲氨基苄叉）酮／二苯基碘鎓盐复合体系的电子转移光显色

不同的双－（ｐ－Ｎ，Ｎ－二甲氨基苄叉）酮ＤＭＢＫ和二苯基碘盐（ＤＰＩＯＦ）复合，组成一种新型的电子转移光显色体系，ＤＭＢＫ／ＤＰＩＯＦ复合体系在暗处有良好的热稳定性。在光作用下很快发生从激发态ＤＭＢＫ至ＤＰＩＯＦ的电子转移，并伴随ＤＭＢＫ染料的褪色，测得ＤＭＢＫ光褪色速度的次序为：ＤＭＢＡ＞ＤＭＢＰ＞ＤＭＢＨ。与此同时，电子转移又引起新的光显色反应，对ＤＭＢＡ化合物，在７００ｎｍ处出现新吸收峰。其光密度随光照时间而增长，然而，ＤＭＢＰ和ＤＭＢＨ体系这种光显色现象并未观察到，这可能由于它们的中间产物不能共平面的缘故，ＤＭＢＡ的光显色速度和最大密度明显取决于浓度和溶剂性质。本文对这种短波区光褪色和长波区光显色的光化学反应过程作了讨论。     

国内外邻苯二甲酸酯类增塑剂的现状和展望

对邻苯二甲酸酯类增塑剂的国内外现状作了评述,并对我国提高DOP和高分子量邻苯二甲酸酯类增塑剂的比例、降低DBP的比例、开发高性能的复合增塑剂提出了积极的建议。