丙烯酸酯无皂乳液聚合体系的研究进展

综述了丙烯酸酯无皂乳液聚合体系的最新发展,包括亲水性共聚单体、离子型单体、反应型乳化剂、挥发性乳化剂和助溶剂参与的聚合体系等,对这些丙烯酸酯无皂乳液聚合的方法与机理进行了归纳.指出了丙烯酸酯无皂乳液聚合的发展方向,对丙烯酸酯无皂乳液的良好应用前景进行了展望.     

有机硅改性丙烯酸酯乳液的合成及其性能研究

以SDS、OP-10为乳化剂,过硫酸钾和亚硫酸氢钠为氧化还原引发体系进行有机硅改性丙烯酸酯乳液聚合研究,比较不同工艺条件对乳液聚合及其性能的影响.研究结果表明有机硅后加工艺得到的乳液性能优于有机硅先加工艺得到的乳液.采用红外光谱表征硅丙共聚物的组成、结构,表明用不同工艺均能成功地在丙烯酸酯聚合物上引入有机硅.透射电镜表明得到的硅丙乳液为核壳结构.     

脂肪酸甲酯磺酸钠作乳化剂的丙烯酸酯乳液聚合研究

以甲基丙烯酸甲酯、丙烯酸丁酯、丙烯酸为单体,脂肪酸甲酯磺酸钠C16-MES为乳化剂,通过乳液聚合制备了丙烯酸酯共聚物乳液.根据Davies法计算了C16-MES的HLB值在12.8左右,并且考察了乳化剂用最、引发剂种类及用量、单体配比对聚合稳定性及乳液稳定性的影响规律.实验结果表明,以C16-MES为乳化剂制备的不同单体配比的丙烯酸酯共聚物乳液稳定,随着乳化剂用量的增加,聚合反应速率增大;引发剂用量相同时,氧化还原引发体系引发的丙烯酸酯乳液聚合速率大于热引发体系.乳胶粒的粒径都在103～200 nm.     

丙烯酸酯乳液聚合研究进展

综述了近几年来丙烯酯乳液聚合方法新进展,包括反应性乳化剂存在下的乳液聚合、超浓乳液聚合、Reversible addition fragmentation chain transfer(RAFT)种子乳液聚合及氧化还原引发的乳液聚合等。另外,对不同丙烯酸酯乳液体系的动力学研究也做了详细阐述。     

丙烯酸酯乳液聚合研究进展

综述了近几年来丙烯酯乳液聚合方法新进展,包括反应性乳化剂存在下的乳液聚合、超浓乳液聚合、Reversible addition fragmentation chain transfer(RAFT)种子乳液聚合、辐射及氧化还原引发的乳液聚合等。另外,对不同丙烯酸酯乳液体系的动力学研究也做了详细阐述。     

"Winsor I-like"法合成聚丙烯酸酯微乳液的工艺及机理探讨

采用"Winsor I-like"型微乳液聚合法合成了聚丙烯酸酯微乳液,考察了聚合工艺、乳化体系、引发体系等因素对丙烯酸酯微乳液粒径及性能的影响,探讨了聚合机理.研究表明,预乳化种子微乳液聚合工艺更有利于制备稳定、粒径小且分布窄的聚合物微乳液;动态光散射研究表明微乳液聚合成核方式主要为均相成核和单体微珠滴成核.     

有机硅氧烷改性丙烯酸酯乳液的聚合稳定性分析

在用乳液聚合合成有机硅改性丙烯酸酯微乳液过程的基础上，着重考察了有机硅氧烷种类及用量、有机硅氧烷的加入方式、乳液的pH值以及聚合温度等对有机硅改性丙烯酸酯微乳液聚合过程稳定性的影响。实验结果表明，采用含异丙氧基取代基的硅烷有助于乳液聚合体系的稳定；并且控制硅氧烷用量和聚合体系的pH值、采用后交联技术有助于提高有机硅改性丙烯酸酯乳液聚合过程的稳定性。     

有机硅改性丙烯酸酯乳液的聚合方法及研究进展

介绍了5种有机硅改性丙烯酸酯乳液的聚合制备方法,包括细乳液聚合、种子乳液聚合、微乳液聚合、无皂乳液聚合以及乳液互穿聚合物网络,分析了各种制备方法的特点,指出了有机硅改性丙烯酸酯乳液的应用前景。     

细乳液聚合法制备PUA杂合乳液研究进展

聚氨酯-丙烯酸酯(PUA)杂合乳液可以弥补聚氨酯乳液和丙烯酸酯乳液各自的不足,使聚氨酯良好的耐磨性和机械性能与丙烯酸酯良好的耐候性与耐水性有机结合,从而达到优势互补.介绍了应用细乳液聚合法制备PUA杂合乳液的优势,综述了近年来细乳液聚合法在制备PUA杂合乳液的机理和应用研究方面的进展.     

保护胶体在高固含量弹性丙烯酸酯乳液聚合中的应用

为了降低高固含量弹性丙烯酸酯乳液聚合的凝聚率,选择了聚甲基丙烯酸钠作为丙烯酸酯乳液聚合的保护胶体,研究了其用量对乳液聚合和乳液性能的影响,探讨了它对丙烯酸酯乳液的稳定机理。研究结果表明,聚甲基丙烯酸钠增加了乳液聚合的稳定性,其用量仅为0.2%就可使凝聚率降到;提高了乳液胶膜的耐水性;保持了较低的乳液黏度。     

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。     

A study of miscibility of blends of polybutadienes of varying microstructure

The miscibility of various amorphous polybutadienes with mixed microstructures of 1,4 addition units (cis, 1,4 and trans 1,4) and 1,2 addition units have been investigated. The studies here involved optical transparency, differential scanning calorimetry, and small angle light scattering. It was found that a 90 percent (cis) 1, 4 addition polybutadiene was immiscible with high (91 percent) 1,2 addition polybutadiene. Reduction of the 1,2 content to 71 percent induced an upper critical solution temperature (UCST) with the cis 1,4 polymer. Polybutadienes with 50 percent and 10 percent 1,2 contents were miscible above the crystalline melting temperature of the cis 1,4 polybutadiene. Immiscibility of the 91 percent 1,2 addition polymer was also found with a 10 percent 1,2 polybutadiene. The latter polymer also exhibits an UCST with the 71 percent 1,2 polymer. The results are used to interpret the characteristics of blends of polybutadienes of varying microstructure.     

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。     

粉煤灰中烧失量检测的不确定度分析

以F类粉煤灰为例,详细介绍了测定粉煤灰中烧失量的步骤、计算数学模型、影响测量不确定度的因素以及各项测量不确定度分量评定,人员、设备、材料、方法、环境都是影响测量不确定的因素。     

生物油的成分分析及物性测定

以添加FeCl2的ZnCl2-KCl混合熔盐裂解纤维素和秸秆,制得生物油。采用傅立叶变换红外光谱法和气相色谱-质谱法分析生物油的成分。结果表明,生物油中成分复杂,含有氧元素、多种有机化合物,主要包括酮类、醛类、酚类及羧酸类等。测定了20～80℃生物油的密度和粘度,发现生物油的密度与温度呈较好线性关系,而生物油的粘度均大于水的粘度,且不同熔盐体系对秸秆生物油的粘度无较大影响。     

分解炉扩径的技术改造

我厂3号回转窑(Φ4m×60m)生产线在1996年年底由SP窑(产量912t/d)改为NSP窑(产量1320t/d),预分解系统为四级旋风预热器带离线式分解炉     

Process of acceleration of filtration of viscose

Conclusions It is significant that the purification on a single passage of viscose through porous ceramic corresponds to the result of a two-stage filtration of it in industrial filter-presses with standard fillings.Kiev Combine. Kiev Technological Institute of Light Industry. Translated from Khimicheskie Volokna, No. 3, pp. 20–22, May–June, 1969.     

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