Environmentally Friendly Polyurethane Composites: Preparation, Characterization and Mechanical Properties

The waterborne polyurethane (PU) prepolymer was prepared based on isophorone diisocyanate (IPDI), polyester polyol (N220), dimethylol propionic acid (DMPA) and hydroxyethyl methyl acrylate (HEMA). The modified waterborne polyurethane–acrylate (PUA) emulsions were obtained with different proportions of acrylate (butyl acrylate and methyl methacrylate) and initiating agent by in situ dispersion technique. The structures and thermal properties of prepared PU and PUA were analyzed and characterized with FT-IR, UV–Vis spectroscopy and DSC. The PUA hybrid samples had lower glass transition temperature of hard segment and higher decomposition temperatures than PU sample. Performances of the emulsion and film were studied by means of apparent viscidity, particle size and polydispersity, surface tension and mechanical properties. The results indicated that the particle sizes of the PUA dispersions were larger than those of the pure PU and the solvent resistance, mechanical properties of PUA films was improved compare with the unmodified polyurethane film. The film had the biggest hardness and the least water absorption when the BA/MMA mass ratio 5:5 modified PU. The obtained PUA have great potential application such as coatings, leather finishing, adhesives, sealants, plastic coatings and wood finishes.     

Utilization of coal fly ash in China: a mini-review on challenges and future directions

Environmental Science and Pollution Research - The rapid economic development in China places a large demand for energy, and as a result, thermal power plants in China are producing an enormous...     

The improved activity of Co3O4 nanorods using silver in the catalytic oxidation of toluene

Environmental Science and Pollution Research - Co3O4 nanorods with diameters of ~0.15 μm and lengths of ~1 μm were prepared using a hydrothermal method via the assembly of microcrystals...     

Groundwater geochemical signatures and implication for sustainable development in a typical endorheic watershed on Tibetan plateau

Environmental Science and Pollution Research - Groundwater resource is significantly important for sustainable development of the world, especially for arid endorheic watersheds. A total of 28...     

Arsenic biotransformation and an arsenite S-adenosylmethionine methyltransferase in plankton

<正>Arsenic(As)is a well-recognized toxicant and carcinogen.Chronic exposure to inorganic arsenic causes a range of human cancers(e.g.,skin,bladder,and lung)and increases the risk of developing diabetes,hypertension,and cardiovascular and neurological diseases.The prevalence of arsenic species and the severity of their health effects continue to drive and demand for extensive research(Carlin et al.,2016).     

一种生物除臭方法及装置的研究

文章介绍了一种生物除臭的方法,这种方法是将装有碳质填料的反应包悬挂于好氧池中,反应包在好氧池中,历经曝气挂膜20~30天;就可以将装有碳质填料的反应包/或碳质填料放于生物除臭装置内;然后向生物除臭装置通入湿润的臭气,就可以将其生成水、二氧化碳、硫酸、硝酸和亚硝酸.使臭气被氧化,转化成无污染的物质,由于它的转化效率高,符合现代生产的高效性,因此一定会在生产实际中受到欢迎.     

兰州市废旧手机产生量预测分析研究

手机普及率日益提高,随之产生的废弃量也日益增多,分别采用时间梯度模型、市场供给A模型、斯坦福(stanford)模型对兰州市2013年-2022年废旧手机的产生量进行了预测.结果显示,不同模型预测结果之间存在较大差异,市场供给A模型和斯坦福(Stanford)模型的预测结果比较接近,均大于时间梯度模型的预测结果,三种模型预测的兰州市2022年废旧手机的产生量分别为40.40万、46.67万和21.04万部.总体上看,兰州市废旧手机的产生量增长趋势较快.     

旅游不文明行为风险形成机理研究

如何有效治理旅游不文明行为、实现文明旅游已成为目前我国旅游研究的热点和焦点问题。辨识旅游不文明行为风险影响因素,分析旅游不文明行为风险形成机理,有助于从源头上根治旅游不文明行为的发生。为此,在分析相关文献及案例的基础上,根据危险源理论,从人、物、环境及管理等四个维度出发,提炼出导致旅游不文明行为风险的影响因素,并借鉴物理学中触发器工作原理,分析旅游不文明行为风险形成过程,建立旅游不文明行为风险形成机理模型。结果表明:所建立风险形成机理模型可以客观反映旅游不文明行为风险形成过程及其相互作用路径,可为旅游不文明行为治理提供参考依据和破解途径。     

Factors influencing the contents of metals and As in soils around the watershed of Guanting Reservoir, China

Topsoil samples from 61 sites around the Guanting Reservoir,China,were measured for Cu,Zn,Cr,Ni,Cd,Pb and As concentrations.The mean concentrations of Cu,Zn,Cr,Ni,Cd,Pb and As were 16.8,59.4,37.8,18.3,0.32,20.1 and 8.67 mg/kg dry weight,respectively.Factors that influence the dynamics of these metals in soils around the watersheds of Beijing reservoirs were examined.The influence of atmospheric deposition,land use,soil texture,soil type and soil chemical parameters on metal contents in soils was investigated.Atmospheric deposition,land use and soil texture were the important factors affecting heavy metal residues.Soil type and soil chemical parameters were also involved in heavy metal retention in soils.The data provided in this study are considered crucial for reservoir remediation,especially since the Guanting Reservoir will serve as one of the main drinking water sources for Beijing in the foreseeable future.