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81.
Sung‐Jun Cho 《应用聚合物科学杂志》2003,88(8):1904-1910
The polymerization of ?‐caprolactam between the interlamellar spaces of the [TEACOOH]–montmorillonite intercalations complex was attempted using Na–montmorillonite and 10‐carboxy‐n‐decyltriethylammonium bromide to achieve [TEACOOH]–polycaprolactam–montmorillonite, in which montmorillonite (inorganic polymer) is chemically bonded with the polycaprolactam (organic polymer). The results of X‐ray and IR analysis for the samples obtained after polymerization showed that the polymerization reaction has been successfully accomplished. For the purpose of studying the polymeric reaction product more precisely, we have isolated the polymerized product from the silicate layers and analyzed it with X‐ray diffractometer and IR spectrometer. Comparison of the results of X‐ray and IR analysis between the isolated polymer and the polymer that was synthesized by the reaction of ?‐caprolactam only with the organic cation without montmorillonite showed that both obtained polymers are the same compounds. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1904–1910, 2003 相似文献
82.
This work was undertaken to discuss in depth the vital differences in the morphological development during synthesis, and properties of starch‐g‐poly‐(vinyl acetate) copolymers using two different initiators, potassium persulfate (KPS) and ceric ammonium nitrate (CAN). KPS‐initiated system gave relatively low values of grafting ratio and grafting efficiency, indicating a great tendency for the formation of poly(vinyl acetate) homopolymer (PVAc). Yet, higher values were seen for the CAN‐initiated system. Transmission electron microscope observations indicated a relatively broad distribution of latex particles for the KPS‐initiated system. The surface potential of latex particles was about ?3.5 mV, which turned out to be insufficient to maintain stability of latex particles. On the other hand, a uniform particle size distribution was found for the CAN‐initiated system, as the surface potential of latex particles was 21.5 mV. Moreover, radicals on starch molecules were generated directly through a redox reaction with positively charged ceric ion. The hydrophobic PVAc chains were thus grafted on starch, resulting in an amphiphilic graft copolymer, which provides a sufficient stabilization degree as a role of surfactant to render a relatively uniform distribution of latex particles. The synthesized starch‐g‐poly(vinyl acetate) copolymers were further converted to starch‐g‐poly(vinyl alcohol) through saponification, which were subjected to evaluations regarding the biodegradation and cell culture capability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3017–3027, 2006 相似文献
83.
84.
以聚乙二醇-4000钾盐为引发剂.合成了食不同长度聚醚链段的聚D.L-乳酸-聚乙二醇-聚D.L-乳酸(PLA-PEG-PLA)三嵌段共聚物。考察了溶剂用量、引发剂用量、反应温度和时间、PEG分子量、不同溶剂对聚合反应的影响。以1H-NMR、IR、DSC、GPC对共聚物进行了表征。 相似文献
85.
羟基乙酸的合成与应用 总被引:2,自引:0,他引:2
概述了羟基乙酸几种主要工业合成方法的工艺条件及存在的主要问题,即氯乙酸水解法、氰化法、甲醛羰基化法和一氯乙酸钾水解法。并对羟基乙酸在化学清洗、助剂和材料等方面的应用进行了详细的介绍。最后对羟基乙酸在国内外的生产现状进行分析,并对国内羟基乙酸今后的发展提出几点建议。 相似文献
86.
P. R. Ernani 《Nutrient Cycling in Agroecosystems》1995,45(3):193-197
The electrolyte concentration of the soil solution affects the availability of some nutrients in the soil, especially of P, but it is not know at what salt concentration the reactions start to be significantly affected and their magnitude. This study was carried out to evaluate the effect of rates of potassium chloride (KCl) on some soil parameters that determine supplying of P, K, Ca, Mg, and Al in an unlimed acid soil. Increasing rates of KCl (from zero up to 2000 mg K kg–1) were applied to soil samples fertilized with 360 mg P kg–1. Solution (Cli) and exchangeable (Csi) forms of P, Ca, Mg, K, and Al were determined in the treated soil samples after 30-days of incubation; cation activity in solution and their selectivity coefficients were then calculated. Addition of KCl at rates equal to or above 500 mg K kg–1 caused a large relative increase on P in the soil solution (Pli) but a small and insignificant increase on the absolute value of Pli. All forms of soil K increased with increases on K applied, and buffer power for K varied according to the range of soil K. At all KCl rates, K displaced Ca, Mg, and Al from the solid phase to the soil solution, but had no effect on the extractable values. The relative preference of cations for the adsorption sites increased with increase on cation valency, and only those selectivity coefficients involving K were affected by K applied. 相似文献
87.
采用双通道的FP-640火焰光度计对磷矿中钾、钠元素进行联合测定试验。试验结果表明:在0.1%~1.0%区间内,K2O的相对标准偏差(RSD)为1.88%~2.93%,回收率为96.6%~102.7%;Na2O的相对标准偏差(RSD)为1.05%~2.10%,回收率为97.3%~101.2%。 相似文献
88.
89.
污水COD超标的影响因素及解决措施 总被引:4,自引:0,他引:4
通过对总排污口污水中主要还原性物质逐项进行掩蔽,分析掩蔽前后污水COD值的变化,找出了影响COD的主要因素并提出了改进措施,使排污总口COD值大幅降低。 相似文献
90.
十六烷基三甲基溴化铵活化催化合成香豆素 总被引:1,自引:0,他引:1
以无水碳酸钾为催化剂、十六烷基三甲基溴化铵(HTMAB)为活化剂,用水杨醛和醋酸酐为原料通过Perkin反应合成香豆素,研究了物料比、催化剂用量和HTMAB用量和反应近结束时保温时间对产率的影响。结果表明:用HTMAB为活化剂,可有效活化碱催化剂无水碳酸钾,提高了其碱性,与无HTMAB时相比,香豆素产率有较大提高,其最佳反应条件是n(水杨醛):n(乙酸酐):n(碳酸钾):n(HTMAB)为1.00:3.00:0.25:0.03,反应温度185℃,反应近结束时保温3h,香豆素产率可达85.3%。 相似文献