“零VOC”丙烯酸酯类涂料的研究进展

在分析水性涂料中有机挥发物（Volatile Organic Compound,VOC）主要来源的基础上,从乳液合成和助剂选择两方面阐述了消除VOC的途径．探讨了利用核壳乳液聚合、引入功能性单体和软硬乳液混拼等思路来解决乳液的高玻璃化温度Tg和最低成膜温度MFT之间的矛盾,着重论述了丙烯酸酯类涂料的制备及其改性．认为“零VOC”涂料适应未来的环境要求．     

环保型防污涂料研究进展

简要介绍了防污涂料中的有毒防污剂和VOC对人体和环境的危害,以及一些国家的应对策略。从防污剂的无毒化、低表面自由能树脂、导电防污涂料、低VOC防污涂料等方面综述了环保型防污涂料研究和开发取得的进展。并提出了需要对导电防污涂料和低VOC防污涂料进一步加强研究的建议。     

石化污水场含烃废气的催化燃烧试验

石化污水场所逸散的臭气主要来源于平流隔油池进出口，其主要成分为烃类等易挥发有机物。经封闭后有组织排放的废气，采用浓度调整－吸附脱硫－催化燃烧工艺技术处理，可达到国家废气排放标准，中型试验表明，其有机废气脱除率在96％以上，并尝试探索了催化燃烧中试的一些规律。     

基于优化SVPWM三相VSR的仿真与研究

介绍了三相电压型PWM整流器(VSR)的拓扑结构和电压定向控制(VOC)的基本原理。针对三相VSR传统中电压空间矢量(SVPWM)算法的缺陷性,提出了一种优化SVPWM调制方法。该方法利用电压空间矢量旋转的幅角来判断扇区,并由相电压的电压差值计算基本电压矢量的作用时间,完全省略了坐标变换和三角函数计算,化简了SVPWM算法步骤。经过MATLAB/SIMULINK建立电压定向控制(VOC)仿真模型,可以证明该优化SVPWM算法的正确性,为改进三相VSR的硬件设计提供了依据。     

低VOC纯丙乳液及乳胶涂料的合成与配制

采用种子乳液聚合工艺合成纯丙乳液,并以其为成膜物质配制低VOC乳胶涂料。实验结果表明,选用种子乳液聚合工艺合成的乳液粒径小,分布均匀,且具有很好的低温成膜性和冻融稳定性;引入功能性单体甲基丙烯酸羟丙酯(HPMA)可提高涂膜的硬度和耐擦洗性能。此外,在配制乳胶涂料时,不添加成膜助剂和防冻剂,选用不含VOC的高效助剂,制得的涂料VOC含量仅为0.3g/L,且具有优异的综合性能,符合低VOC乳胶涂料的要求。     

热湿地区室内挥发性有机物多源散发研究现状

分析热湿地区室内空气污染现状,对影响热湿地区室内空气污染因素的独特特征进行总结。介绍国内外热湿环境下挥发性有机物多污染源散发机制的研究现状,指出湿热条件下室内装修家具等具有多污染源的挥发性有机物散发模型及环境影响因素研究的不足,提出对室内温度场、风速场、湿度场、污染物浓度分布进行模拟仿真的研究方向。     

Managing Exposure to Indoor Air Pollutants in Residential and Office Environments

Abstract Sources of indoor air pollutants in residential and office environments can be managed to reduce occupant exposures. Techniques for managing indoor air pollution sources include: source elimination, substitution, modification, pretreatment, and altering the amount, location, or time of use. Intelligent source management requires knowledge of the source's emission characteristics, including chemical composition, emission rates, and decay rates. In addition, knowledge of mechanical and natural outdoor air exchange rates, heating/air-conditioning duct flow rates, and local exhaust fan (e.g., kitchen, bathroom) flow rates is needed to determine pollutant concentrations. Finally, indoor air quality (IAQ) models use this information and occupant activity patterns to determine instantaneous and/or cumulative individual exposure. This paper describes a number of residential and office scenarios for various indoor air pollution sources, several ventilation conditions, and typical occupant activity patterns. IAQ model predictions of occupant exposures for these scenarios are given for selected source management options. A one-month period was used to compare exposures; thus, long-term exposure information is not presented in this paper.     

Comparison Of Volatile Organic Compounds From Processed Paper And Toners From Office Copiers And Printers: Methods,Emission Rates,And Modeled Concentrations

The emission of volatile organic compounds (VOC) from nine toner powders and eleven types of processed paper from photocopying machines (6), laser (3) and matrix printers (21, and one carbonless copy fm has been measured. A total of 61 VOC from toner powders were identified by heating (185 °C) the powder for three minutes for thermal desorption and by gas chromatography followed by the use of low and high resolution EI and CI mass spectrometry. VOC from processed paper were analyzed by headspace sampling on Tenax TA from nylon bags. Thirty-one VOC with a wide range of volatility and persistency were identified from processed paper. The total VOC emission from the various types of paper differed substantially. Using the field and laboratory emission cell (FLEC), the calculated initial emission rate of styrene was 5 μg m^?2h^?1 from a freshly processed paper The VOC emission from machines and the processed paper can be reduced by proper choice of o m e equipment. However, an evaluation should consider all potential pollutants.     

Characterization of Linoleum. Part 1: Measurement of Volatile Organic Compounds by use of the Field and Laboratory Emission Cell, “FLEC”⋆

The volatile organic compounds (VOCs) emitted from 12 linoleum samples were measured by use of the “Field and Laboratory Emission Cell” (FLEC) with sampling on Tenax TA followed by thermal desorbtion and GC/FID or GC/MS analysis. Major VOCs were alkanals, alkenals and fatty acids. The emissions were measured after 24 h in FLEC and again after one month's storage in a well ventilated room. The emission profiles of hexanal, nonanal and propanoic acid were modeled for four linoleum samples using a new exponential diffusion model. The time required to reach 50% of the odor threshold concentrations in a standard room was from 113 to 2296 hours. The applicability of the diffusion model for modeling long-term emission needs to be further evaluated considering possible continuous oxidative emission.     

Performance of H‐ZSM‐5‐supported bimetallic catalysts for the combustion of polluting volatile organic compounds in air

The performance of H‐ZSM‐5‐supported bimetallic catalysts with chromium as the base metal in the combustion of ethyl acetate and benzene is reported. A reactor operated from 100 to 500 °C at a gas hourly space velocity (GHSV) of 32 000 h^?1 was used for study of the activity. A combination of 1.0 wt% chromium and 0.5 wt% copper yielded a catalyst (Cr_1.0Cu_0.5/Z) with improved conversion and carbon dioxide yield. Cr₂O₃ (Cr³⁺) and CuO (Cu²⁺) were the predominant metal species in the catalyst. In agreement with the Mars–van Krevelen model, improved reducibility of Cr³⁺ in the presence of Cu²⁺ led to an improvement in activity. The copper content in Cr_1.0Cu_0.5/Z also favored the formation of deep combustion products. Condensation and subsequent growth of coke precursors in the catalyst pores led to the formation of a softer and less aromatic coke fraction while dehydrogenation activity on acid sites formed a harder and more aromatic coke fraction. The use of Cr_1.0Cu_0.5/Z favored the formation of lower molecular weight intermediates, leading to reduction in formation of softer coke. Copyright © 2005 Society of Chemical Industry