丙烯酰氧基螺噁嗪接枝羧甲基甲壳素反应条件的研究

采用接枝共聚法合成了一种具有螺噁嗪侧基的羧甲基甲壳素水溶性衍生物。讨论了反应温度、反应时间、引发剂用量、溶剂用量、单体用量对丙烯酰氧基螺噁嗪接枝羧甲基甲壳素反应的影响。接枝效率最高时反应条件为:羧甲基甲壳素0.4 g,溶剂水50.0 mL,引发剂0.35 mmol,单体3.0 mmol,反应温度70℃,反应时间4.0 h,接枝率为65.0%,接枝效率为25.2%。     

羧甲基甲壳素与丙烯酰胺接枝聚合反应研究

制备了羧甲基甲壳素接枝丙烯酰胺共聚物,讨论了反映温度、时间、引发剂用量、溶剂用量、单体用量对接枝反应的影响。最佳反应条件为：羧甲基甲壳素0．4g,溶济水50mL,引发剂60mg,单体1．6g,反应温度50℃,反应时间3．0h。     

羧甲基甲壳素接枝丙烯酸丁酯共聚物的制备及水溶性

制备了羧甲基甲壳素接枝丙烯酸丁酯共聚物,讨论了反应温度、时间、引发剂用量、溶剂用量、单体用量对接枝反应的影响。最佳反应条件为:羧甲基甲壳素0.3g,溶剂水30mL,引发剂50mg,单体1.2g,反应温度60℃,反应时间3.5h。用红外光谱对接枝产物进行了表征,考察了不同接枝率的产物在10种常见溶剂中的溶解性,结果表明不同接枝率的接枝产物都有水溶性。     

丙烯腈接枝羧甲基甲壳素水溶性衍生物的制备和表征

以羧甲基甲壳素和丙烯腈为原料,制备了丙烯腈接枝羧甲基甲壳素衍生物,讨论了反应温度、反应时间、溶剂用量、引发剂用量、单体用量对接枝反应的影响。结果表明,最佳反应条件为:羧甲基甲壳素0.4 g,溶剂水40.0 mL,过硫酸铵50.0 mg,丙烯腈2.5 g,反应温度60℃,反应时间2 h。所制共聚产物具有水溶性,分析了产物具有水溶性的原因。     

羧甲基甲壳素与醋酸乙烯酯接枝共聚反应研究

以过硫酸铵为引发剂,合成了醋酸乙烯酯接枝羧甲基甲壳素共聚物,采用红外光谱对接枝共聚产物进行了表征。考察了溶剂用量、反应温度、反应时间、引发剂用量、单体用量等因素对反应接枝率和接枝效率的影响,获得了最佳反应条件。结果表明：羧甲基甲壳素0．4g,溶剂水50．0mL,醋酸乙烯酯1．5g,过硫酸铵60．0mg,在70℃反应3．0h时接枝效率最高,可达65．1％。接枝共聚改性反应可以扩展羧甲基甲壳素的应用价值。     

羧甲基甲壳素与丙烯酸钠溶液接枝共聚反应研究

以过硫酸铵为引发剂,制备了羧甲基甲壳素接枝丙烯酸钠共聚物,讨论了反应温度、反应时间、引发剂用量、单体用量对接枝率的影响。红外光谱分析说明接枝反应是由过硫酸铵和羧甲基甲壳素上存在的氨基组成的氧化还原引发体系引发的。     

过硫酸钾引发羧甲基甲壳素和丙烯酸钾溶液接枝聚合

以过硫酸钾为引发剂,水为介质,制备了羧甲基甲壳素接枝丙烯酸钾共聚物,讨论了反应温度、反应时间、引发剂用量、单体用量对接枝率的影响,获得了最佳反应条件。结果表明：在含羧甲基甲壳素0．3g的30．0mL水溶液中,加入过硫酸钾50．0mg,丙烯酸钾水溶液8．0mL,于60℃反应120min时接枝率最高,达305．1％。接枝共聚物具有水溶性。接枝共聚改性反应可以扩展羧甲基甲壳素的应用价值。     

丙烯酸丁酯改性C_9石油树脂的研究

利用丙烯酸丁酯改性C9石油树脂,以AIBN为引发剂,以正庚烷为溶剂,采用自由基溶液聚合法合成了C9石油树脂/丙烯酸丁酯接枝共聚物。采用单因素实验和正交实验,考察了反应中单体的选择、单体用量、引发剂用量、反应温度、反应时间对接枝率以及单体转化率的影响。最佳反应条件为:反应温度为80℃,反应时间为4 h,引发剂用量为0.75 g,丙烯酸丁酯的用量为12%,在此条件下,产物的接枝率为27.03%。红外光谱分析证实了接枝产物的生成。     

羧甲基纤维素-丙烯酰胺接枝共聚的工艺条件研究

以羧甲基纤维素(CMC)为接枝底物,丙烯酰胺(AM)为接枝单体,过硫酸铵和亚硫酸氢钠为引发剂,N,N′-亚甲基双丙烯酰胺(MBAM)为交联剂,制备羧甲基纤维素-丙烯酰胺接枝共聚物。对CMC/AM质量比、MBAM用量、引发剂用量、反应温度、反应时间等因素对反应的影响进行了探讨。结果表明,聚合的最佳条件为:CMC/AM为6/1~7/1,交联剂MBAM为0.003 g,引发剂为单体质量的1%~2.5%,反应温度为45℃,反应时间为3~3.5 h。     

废弃聚苯乙烯颗粒接枝改性制备防水涂料的研究

以丙烯酸（AA）和丙烯酸丁酯（BA）为共聚单体,采用溶液接枝法对废聚苯乙烯（PS）进行接枝改性制得PS接枝共聚物,然后以PS接枝共聚物的乳液为基料制备改性PS防水涂料。研究了引发剂用量、单体用量、反应温度和反应时间对PS接枝共聚物接枝率的影响,以及填料和增塑剂的用量对改性PS防水涂料性能影响。结果表明,PS接枝共聚物的最佳合成工艺为：PS用量为30 g,溶剂用量为60 mL,引发剂用量为2.2 g,单体用量为20 g,反应温度为85 ℃,反应时间为25 h;向改性PS乳液中填加10 %的填料和4 %的增塑剂制得的防水涂料性能最佳：耐水时间为25 h,耐盐时间为27 h,表干时间为18 min,冲击强度达50 kg·cm。     

Graft copolymerization of vinyl monomers onto chitin with cerium (IV) ion

Graft copolymerization of vinyl compounds onto chitin was studied, and an efficient and reproducible procedure has been established, cerium (IV) being used as the initiator. The reactions with acrylamide and acrylic acid onto powdery chitin were carried out under various conditions to elucidate the polymerization behavior in terms of grafting percentage. The amount of cerium (IV) affected the polymerization most strikingly, and grafting percentages showed maxima with suitable amounts of initiator for both the monomers. As a solvent water proved to be superior to aqueous nitric acid except the reaction with a small amount of initiator. Under appropriate conditions, around 240 and 200% grafting percentages were achieved for acrylamide and acrylic acid, respectively. The resulting graft copolymers showed much improved affinity for solvents and hygroscopicity compared to the original chitin.     

Preparation and evaluation of the chitin derivatives for wastewater treatments

The chitin thiocarbonate—Fe(II)H—H₂O₂ redox system was investigated as the initiator for the graft copolymerization of acrylonitrile and acrylic acid monomers onto chitin powder. The reaction with vinyl monomers onto chitin was carried out under various parameters of the graft copolymerization reaction to elucidate the polymerization behavior in terms of graft yield. Reactions of chitin—acrylonitrile graft copolymer with hydroxyl amine hydrochloride, as well as, sodium hydroxide were conducted in order to obtain chitin—(amidoxime-co-acrylonitrile) and chitin-(acrylate-co-acrylamide) graft copolymers, respectively. The reaction efficiency depends upon the alkali concentration, time, temperature, and on the reactant concentrations. The prepared chitin derivatives were evaluated for use in the wastewater treatments for adsorption and desorption of heavy metal ions as well as acid and basic dyes. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 1939–1946, 1997     

蔗渣纤维丙烯酸高吸水树脂的制备

以蔗渣纤维为原料,丙烯酸为接枝单体,N,N-亚甲基双丙烯酰胺为交联剂,K2S2O8为引发剂,通过溶液聚合的方法合成了蔗渣纤维（sugarcanebagasse,SCB）与聚丙烯酸（polyacrylicacid,PAA）的接枝共聚高吸水树脂（scB—g—PAA）。研究了丙烯酸用量、引发剂用量、交联剂用量以及中和度对吸水树脂吸水倍率的影响,结果表明,该接枝共聚吸水树脂的最佳合成条件是以丙烯酸用量为标准,蔗渣纤维、K2S2O8、交联剂用量分别是10％、2％、0．1％,中和度为80％,共聚物吸水倍率最高为765．7g·g-1。     

The Synthesis of Chitin-g-Poly(vinyl acetate) Copolymers with a Redox Initiator

Vinyl acetate monomer was graft polymerized onto chitin with a redox initiator, cerium ammonium nitrate. Both the graft copolymerization and emulsion polymerization of pure poly(vinyl acetate) (PVAc) were observed during the reaction and a stable dispersion solution was obtained after the reaction. After the PVAc homopolymer was removed by acetone extraction, the grafting efficiency and grafting percentage were calculated from the weight balance. Transmission and scanning electronic microscope were used to observe the morphologies of the reaction product. Experimental results indicated that at initial stage of reaction, graft copolymerization, which occurred on the surface of chitin particles, dominated over the emulsion polymerization. After that, the rate of emulsion polymerization increased greatly and became dominant. The existence of chitin not only provided the stability of the emulsion particles, but also increased the polymerization rate. Structures of copolymers were evidenced with the techniques of Fourier transform infrared and differential scanning calorimeter.     

固相法微晶纤维素接枝甲基丙烯酸甲酯共聚物的制备与表征

以过硫酸铵为引发剂,在少量水存在下,研究了微晶纤维素（MCC）与甲基丙烯酸甲酯（MMA）接枝共聚的反应规律。考察了含水量、反应时间与温度、MMA单体和引发剂用量等因素对接枝共聚反应的影响。实验结果表明,体系含水质量分数为50％左右,MMA用量为MCC质量的20％,过硫酸铵用量为MCC质量的10％,反应温度在80℃,反应时间为40min左右,可得到接枝率和接枝效率均较高的接枝共聚物。通过红外光谱（FTIR）、热重分析法（TGA）以及X射线衍射法（XRD）对合成的接枝共聚物进行了表征。     

氢氧化钠/尿素水溶液中纤维素均相接枝制备高吸水材料

以氢氧化钠／尿素(NaOH／Urea)水溶液为纤维素溶剂，进行了纤维素均相接枝丙烯酸制备高吸水材料的研究。该吸水材料吸去离子水达400多倍、自来水达近200倍。讨论了纤维素在NaOH／Urea水溶液体系中的溶解，考察了反应温度、交联剂用量、引发剂用量对接枝产物吸水性能的影响。