对苯型不饱和聚酯树脂性能的研究

研究了以聚酯回收料为原料生产的对苯型不饱和聚酯树脂的固化性能和耐化学腐蚀性能,分析了影响凝胶时间的各种因素。试验结果表明,所得对苯型树脂具有优良的耐化学腐蚀性能。其耐酸性、耐碱性、耐盐性和耐水性能与间苯UPR树脂相当,其耐溶剂和耐氧化酸性能与双酚A型UPR树脂相当。     

Characteristics of heavy-oil-in-water emulsions containing produced sand

Heavy-oil-in-water (o/w) emulsions containing produced sand were prepared using commercially available emulsifiers. The emulsions were tested in beakers for emulsion type, quality, and sand-retention characteristics. The apparent viscosities of the o/w emulsions were measured. The effects of polymer addition on the apparent viscosity and sand-carrying capability of the emulsions were also studied. The results of the breaker tests indicate that most emulsifier solutions water-wet the beaker wall and temporarily improve heavy-oil flow characteristics. However, most of the chemicals also water-wet the sand particles and cause sand dropout. The Flothin F2 chemical alone showed stable oil dispersion and, in combination with the Flocon 4800C polymer, showed very good sand-retention, viscosity-reduction, and stable oil-dispersion characteristics.     

沸石滤池的净水作用

利用沸石的过滤吸附作用与石英砂进行对比试验 ,试验表明 ,粒径为 0 .8～ 1 .2mm的天然沸石对水中浊度、有机物、苯酚及氨氮的去除效果均好于同粒径石英砂 ,且水头损失小 ,运行周期长 ,是一种经济可行的水处理滤料。     

不饱和聚酯树脂光固化工艺的研究-光引发剂浓度

本文选用TPO、651两种光引发剂，分别配制引发剂浓度为0．25、0．5、1、2wt％的不饱和聚酯体系。通过测定光固化试样的显微硬度分析光引发剂浓度对固化程度的影响。结果表明，提高引发剂浓度能抑制氧阻聚的作用，但对于较厚的试样，引发剂浓度过高会导致固化不完全。     

热固性树脂基防火涂料的研究

讨论了不同单组分树脂基体和树脂复配体系以及树脂用量对防火涂料性能的影响。确定以不饱和聚酯树脂和环氧树脂为树脂基体,以聚磷酸铵、三聚氰胺和季戊四醇为防火助剂,辅以填料和其他助剂,配制膨胀型防火涂料。实验结果表明,当树脂基体的质量分数为28%,涂层厚度为1.90 mm的条件下,涂料的防火性能最好,耐燃时间超过210 min。     

新疆某黄土的土水特征及其分形描述

本研究采用新疆某引水渠道边坡的黄土填料进行土水特征曲线试验,研究压实度和应力水平对土料的土水特征的影响规律。针对试验结果,本研究首先采用经典的van Genuchten模型进行曲线拟合。然后采用分形理论进行土水特征曲线的比较分析。结果表明:(1)随着压实度的增加,土水特征曲线向下移动;随着轴向应力的增加,土水特征曲线也会有所下移;(2)相应于孔隙分布,该土料的土水特征曲线具有明显的分形特性;(3)在相同压实度下,不同应力水平的SWCC分形拟合基本平行。采用本文所述的分形方法,在已知不同应力水平下的孔隙率时,可较为合理的从一个应力水平下的土水特征曲线推求其它应力水平下的土水特征曲线。     

砂子负载纳米TiO2薄膜光降解有机污染物的研究

从光化学的角度，对砂子负载纳米二氧化钛薄膜，光催化剂降解工业污水中的有机污染物的过程进行分析与研究，探讨了多种因素对光降解的影响。实验显示在紫外光和纳米二氧化钛共同存在下，能对工业污水进行处理，砂子负载纳米二氧化钛进行光催化降解的最佳条件：纳米二氧化钛的质量分数为2％，焙烧温度约300℃，工业污水的pH为6．0～7．0。     

双环戊二烯改性不饱和聚酯树脂研究进展

较详细地介绍了双环戊二烯改性不饱和聚酯树脂的机理、合成路线(初始法、半酯化法、酸酐法、后期法、封端法和水解法)及国内外双环戊二烯改性不饱和聚酯树脂在气干性、低苯乙烯挥发、低收缩性与力学性能方面的研究进展,提出了今后的研究方向。     

Allelopathic properties ofPolygonella myriophylla

Polygonella myriophylla is a perennial shrub endemic to the Florida scrub. Striking bare zones surround maturePolygonella stands. Quantitative measurements of root distribution show that fewPolygonella roots extend into the bare zones, supporting the hypothesis that the bare zones result from chemical interference byPolygonella with the growth of other species. Bioassays of soils collected biweekly for one year from beneathPolygonella, the bare zone, and adjacent grassed areas confirm that the germination and growth of grasses is reduced inPolygonella soil and soil from the surrounding bare zone. Compared to adjacent grassed area soil, the average germination of bahiagrass (Paspalum notatum) was 71% inPolygonella soil and 81% in bare zone soil, and average shoot dry weight was 48% inPolygonella soil and 81% in bare zone soil. Seasonal variation in the inhibition of grass germination and growth was not pronounced.     

Role of sand on curing of partex surface by UV radiation

A partex surface was modified by a UV‐curing system with epoxy acrylate (EB‐600). A set of formulations was prepared with oligomer and the trifunctional monomer trimethylol propane triacrylate in different combinations of percentages (1–5%) of sand to study the role of sand in various physical properties of UV‐cured thin films, as well as partex surfaces. Increased pendulum hardness (PH), gloss, adhesion, and abrasion values were obtained by the addition of sand into the partex surfaces. The best results were obtained with the formulation containing 3% sand. An enhanced PH and a decreased percentage of gel content of the UV‐cured film was observed with an increase of the sand concentration. A simulated weathering test was performed with partex surfaces cured by a formulation containing 3% sand in the base coat. The losses of the physical properties were found to be lower over the surface treated with the formulation containing sand. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2385–2392, 2002