一种水性硅氟聚合物及其制备方法和该聚合物的水分散物

本发明涉及一种水性硅氟聚合物及其制备方法，其特征是按质量份数计，由甲基含氢硅油100份，烯丙醇聚氧乙烯聚氧丙烯醚1～500份，丙烯酸氟化烷基酯0．1～500份和含端反应性双键有机硅烷偶联剂0～80份混合后，在催化剂存在下加聚反应合成得到。本发明还涉及这种水性硅氟聚合物的水分散物，

从含氢硅油制取水性氟硅聚合物

在无溶剂的条件下,通过硅氢加成法将烯丙基聚氧乙烯聚氧丙烯醚,氟化丙烯酸烷基酯接枝共聚到甲基含氢硅油侧链,成功地合成了一系列有机氟硅聚合物.通过高速剪切乳化法可制得不同质量投料比时的水性氟硅聚合物水分散物.采用FTIR,1HNMR和TEM对有关产物和乳液进行了结构分析,并进一步系统研究了水分散物表面张力,流变性等性能,结果表明:质量分数为2.0%的水性氟硅聚合物水分散物的表面张力降低至22.00～26.00N/m,其黏度随着剪切速率的增大有剪切变稠现象发生,且不同质量投料比时,其粒子粒径大小及形状也有较大差别.

Synthesis, characterization and application of a dispersant based on rosin for coal-water slurry

A rosin derivative and maleopimaric acid diethanolamide(MAD), was synthesized, characterized by FTIR and1 H NMR, and applied as dispersant for the coal-water slurry(CWS) prepared from Chinese Shenfu coal. The CWS application performance investigation shows that the MAD dispersant has better abilities in reducing CWS viscosity and stabilizing the slurry than a commercial dispersant—sulfonated naphthalene-formaldehyde condensate(SNF). The physicochemical property investigation of the two tested dispersants shows that the adsorption amount of the MAD at coal-water interface is much larger than that of SNF, and the MAD has better wetting property than the SNF on the coal surface. It indicated that the excellent capabilities of MAD are related to the adsorption mode of standing upright on the coal surface. Based on the above, the mechanism of dispersion and stabilization of the CWS prepared from MAD dispersant is presented.

Debris Flow Formation Process and Critical Hydrodynamic Conditions in the Meizoseismal Area of the Wenchuan Earthquake

Abstract： The Wenchuan earthquake generated strong surface disturbances and triggered a large number of loose deposits, resulting in the disaster- prone environment with special watershed hydrological characteristics. This paper was to propose a debris flow formation process and explore the permeability characteristics and critical hydrodynamic conditions of the loose deposits triggered by the earthquake. The Guo Juanyan gully （31005＇27＂ N to 31005＇46＂ N, 103036＇58＂ E to 103037＇09＂ E） in Du Jiangyan City, located in the meizoseismal areas of the Wenchuan earthquake, was chosen as the study area and the disaster-prone environment was analyzed. The formation process of the debris flow was first proposed using a stability analysis, and then, the permeability characteristics of loose deposits were determined via in situ permeability experiments. Finally, the critical 1 h rainfall was simulated through a distributed hydrological model and verified by field observations. The formation process of debris flow could be divided into three stages based on the relationship between the hydrodynamic force and loose deposit resistance. The critical 1 h rainfall amounts under three antecedent moisture conditions （I-dry, Ⅱ-normal and Ⅲ-wet） were 52 mm/h, 43 mm/h and 34 mm/h, respectively. This study proposed a debris flow formation process in the meizoseismal areas of the Wenchuan earthquake based on the stability analysis and defined the rainfall threshold for debris flow early warning at the local level, which is significant for debris flow mitigation and risk management.

Preparation and Characterization of Hybrid Aqueous Dispersions Composed of Silica Sol and Poly(styrene-co-acrylate)

A stable silica sol with 3-5 nm in diameter, which can form homogeneous film without crack, was prepared and characterized. Then, the inorganic-organic hybrid aqueous dispersion composed of such a silica sol and an emulsion of styrene （St） and acrylate （Ac） copolymer was prepared and the hybrid effect between the silica sol and poly（St-co-Ac） was observed by Fourier transform infra-red （FT-IR） spectroscope. The toughness of the film prepared by this kind of hybrid aqueous dispersion was excellent, as it was enhanced appreciably by commixing with a small amount of poly（St-co-Ac） emulsion. Some amino-polysiloxane modified hybrid aqueous dispersions were also prepared and the properties of the modified dispersions and their films were investigated. The experimental results showed that the film prepared with such an amino-polysiloxane modified hybrid dispersion exhibited excellent hydrophobicity and low surface energy after heat treatment for 1.5 h, during which the formation of the graft copolymer was observed. The surface energy of this film decreases as a result of the enrichment of siloxane segments on the film surface.

A Reduced Mechanism for Flame Inhibition by Phosphorus-containing Compounds Based on Level of Importance Analysis

A reduced mechanism for propane/air combustion and its flame inhibition by phosphorus-containing compounds (PCCs) is constructed with the level of importance (LOI) method. The analysis is performed on solutions of freely propagating premixed flames with detailed chemical kinetics involving 121 species and 682 reactions proposed by Jayaweera et al. For the non-homogeneous reaction-diffusion system, the chemical lifetime of each species is weighted by its diffusion timescale, and the characteristic flame timescale is used to normalize the chemical lifetime. The definition of sensitivity in LOI is extended so that multi-parameters can be used as sensitivity targets. Propane, oxygen, dimethyl methylphosphonate (DMMP), and flame speed are selected to be perturbed for sensitivity analysis, the species with low LOI index are removed, and reactions involving the redundant species are excluded from the mechanism. A skeletal mechanism is obtained, which consists of 57 species and 268 elementary reactions. Calculations for laminar flame speeds, key flame radicals and catalytic cycles using the skeletal mechanism are in good agreement with those by using the detailed mechanism over a wide range of equivalence ratio undoped and doped with DMMP.

专利介绍

室温固化耐高温型柔性环氧粘合剂 中国专利1546590(2004—11—17)。该粘合剂由粘合组分和固化组分组成，其中粘合组分又含有增韧组分、耐温组分和增塑剂，固化组分由主体固化剂和固化促进剂组成。固化促进剂为多种成分的混合物。粘合组分与固化组分分别制取，分别封装，使用时现场按比例混合调制。制取的环氧粘合剂具有极好的柔韧性，粘结强度高，室温下的抗冲强度不低于30MPa，且使用温度高，可在300℃下长期使用。

Water Consumption of Seven Forage Cultivars under Different Climatic Conditions in the North China Plain

The objectives of this study were to determine the characteristics of water consumption of seven forage cultivars, ryegrass （Secale cereale L.）, triticale （×Triticosecale Wittmack）, sorghum hybrid sudangrass （Sorghum biolor× Sorghum Sudanense c.v.）, ensilage corn （Zea mays L.）, prince’s feather （Amaranthus paniculatus L.）, alfalfa （Medicago sativa L.）, and cup plant （Silphium perfoliatum L.）, in response to climate variability （especially precipitation）. Field experiments were conducted at Yucheng Integrated Experiment Station from 2005 to 2009. Fifteen irrigated lysimeters were used to measure evapotranspiration （ET） and crop coefficient （Kc） of these seven forage varieties under ample water supply. The mean Kc for alfalfa is 1.08, and the mean Kc for other forage varieties ranges from 0.79 to 0.94. Kc for hibernating forage is higher in wet years than that in dry years, followed by normal years, while for annual forage, Kc is higher in dry years than in normal years, and is the lowest in wet years. For perennial varieties the order is normal years, dry years, and wet years. Among the annual varieties, ensilage corn is the first choice due to its highest average forage N yield and water use efficiency （WUE）. Sorghum hybrid sudangrass is another forage cultivar that grows well under all climatic conditions. It can achieve 1.08-2.31 t ha-1 y-1 N yield under all circumstances. Prince’s feather is sensitive to climate change and its N yield dropped below half even when ample water was applied in dry and normal years. Ryegrass and triticale have the advantage of growing in the fallow phase after cotton is harvested in the North China Plain （NCP） and the latter performed better. For perennial varieties, alfalfa performed better than cup plant in dry years. With ample irrigation, alfalfa can achieve higher biomass and WUE under arid climate condition, but excessive rain caused reduction in production.