两性壳聚糖的制备及其对纸张的增强作用

以壳聚糖-环氧丙基三甲基氯化铵(CTS-ETA)进行羧甲基化改性,制得两性壳聚糖;制备羧甲基化CTS-ETA的优化条件为:m(氯乙酸)∶m(CTS-ETA)=1.5∶1,碱化时间为1h,醚化时间为3h,醚化温度为60℃。将自制改性壳聚糖应用于成纸物理强度的增强,结果表明:两性壳聚糖可用作纸张的增强剂,加入少量(质量分数为0.2%~0.3%)就能对纸张的物理强度有很大的提高。     

两性型聚丙烯酰胺助留助滤剂的合成及其性能研究

以丙烯酰胺(AM)、甲基丙烯酸二甲氨基乙酯氯甲烷盐(DMC)、丙烯酸(AA)为主要原料,采用水溶液接枝共聚,合成了分子质量适宜的两性型聚丙烯酰胺(AmPAM)助留助滤剂,并对其性能做了研究,结果发现,其性能可与德国K350相媲美.     

两性丙烯酸树脂复鞣剂的合成及应用

以丙烯酸 (AA)和甲基丙烯酰氧乙基三甲基氯化铵 (DMC)为原料 ,在水中采用自由基共聚和制备了两性丙烯酸树脂复鞣剂。利用红外光谱 (FTIR)和核磁共振 (13 CNMR)对其结构进行了表征。分别采用浊度法和黏度法测定了该类聚合物的溶解性和黏度行为。应用试验表明 ,共聚物的复鞣性能与其组成和分子量大小有关 ,在丙烯酸聚合物鞣剂中引入阳离子基团 ,可以提高复鞣革的柔软度 ,克服败色现象。通过扫描电镜观测、X -衍射分析证实 ,两性丙烯酸树脂复鞣剂可以分散皮胶原纤维 ,降低胶原纤维的结晶度。     

两性聚丙烯酰胺的絮凝脱水性能研究

将两性聚（甲基丙烯酰氧基乙基三甲基氯化铵－ｃｏ－丙烯酰胺－ｃｏ－丙烯酸）三元共聚物（ＡＰＡＭ）用于生化污泥的絮凝脱水。试验结果表明：该类两性聚丙烯酰胺具有独特的絮凝脱水性能，且以丙烯酸质量摩尔浓度为１５％的ＡＰＡＭ性能最佳。     

两性聚丙烯酰胺的合成及其溶解性的研究

应用水溶液聚合法合成了聚 (丙烯酰胺 /氯化二甲基二烯丙基铵 /氯化甲基丙烯酰氧乙烯基三甲基铵 /丙烯酸 ) [P(AM/DDAC/DMC/AA) ]两性共聚物。采用正交实验方法分析讨论了引发剂用量、聚合体系温度、抗交联剂用量对该两性共聚物溶解性的影响 ,从中优化出最佳反应条件。用傅立叶红外光谱仪对两性共聚物的结构进行了表征。     

两性高相对分子质量聚丙烯酰胺的合成

通过Mannich反应和水解将重均相对分子质量约1.0×107的聚丙烯酰胺改性为两性聚丙烯酰胺(AM-PAM)。以二乙胺和甲醛改性为阳离子聚丙烯酰胺,再以Na2CO3为水解剂,在35-45℃水解2h,得到胺化度42%,水解度15%、重均相对分子质量约1.0×107的AMPAM。用1HNMR、IR对产物进行了结构表征。     

改性鱼油磷酸酯加脂剂的合成及应用

鱼油与乙醇胺在 110℃下 ,进行酰胺化反应 5 h,得到改性鱼油 ,然后在 70 - 80℃下 ,以 P2 O5为磷酸化试剂反应 4 h,使磷酸化改性鱼油中的磷酸单酯 (MAP)含量达 6 0 %以上 ,再中和至 p H为 6 .5 - 7.5 ,最后复配成加脂剂。经该加脂剂加脂后 ,革身柔软、不油腻、弹性好。     

Study on adsorption behavior between Cr(VI) and crosslinked amphoteric starch

Crosslinked amphoteric starches (CASs) with quaternary ammonium cationic and carboxymethyl anionic groups were prepared by a hemidry reaction. Their adsorption behavior for Cr(VI) was investigated, and was found to follow the Langmuir isotherm. The adsorption process was found to be dependent on initial pH, concentration of Cr(VI), dose of CAS, and temperature. The adsorption capacity decreased with increasing degree of substitution of anionic groups. The thermodynamic study indicated that the adsorption process was exothermic, and the enthalpy changes (ΔH^θ), the entropy changes (ΔS^θ), and free energy changes (ΔG^θ) for CASs were determined. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 263–267, 2003     

新颖两性聚合物复鞣剂DR的合成研究

利用二乙基二烯丙基氯化铵(DEDAAC)和甲基丙烯酸等乙烯基类单体(VM)在引发剂过硫酸铵(APS)的作用下，在水溶液中通过共聚合反应制得了一种两性树脂鞣剂，研究了各种聚合条件，如引发剂和单体浓度对共聚合反应的影响。同时用红外光谱(FT-IR)、热失重(TGA)、透射电镜(TEM)对聚合物的结构和性能进行了表征，并进行了应用试验。应用结果表明：该复鞣剂无败色现象，有一定的选择填充性，收敛性小，鞣后成革手感丰满、柔软、革面平细。     

Electrical properties of nickel in silicon

Electrical activity and energy levels as well as diffusion properties of nickel in silicon have not yet been reliably established. In this paper, we investigated the diffusion and the electrical properties of nickel in silicon to confirm that nickel is electrically active and introduces one acceptor and one donor level by combined measurements of Hall coefficient and DLTS, and measurements of the distribution of electrically active nickel in various silicon diodes by DLTS. The former experiments show that bothn- andp- type silicon are compensated by nickel and that nickel introduces an acceptor level ofE _c-0.47 ± 0.04 eV and a donor level ofE _v +0.18 ± 0.02 eV. The concentrations of these two levels are almost identical over the diffusion temperatures from about 800 to 1100° C, indicating that these donor and acceptor levels are due to different charge states of the same nickel center. In the distribution measurements of electrically active nickel in silicon diodes, we inspected how nickel can be observed by DLTS. It was found that the nickel diffusion intop- n junction is rather complicated, the distribution profiles of nickel in the vicinity of thep- n junction being markedly influenced by an additional heating at elevated temperatures after the nickel diffusion. This gives evidence that the difference in silicon devices used in various studies could give rise to different results.