改性聚天冬氨酸三元复合吸水性树脂的制备和性能研究

发布时间：2018-11-02 17:41

【摘要】：吸水性树脂是一种能够吸收大量水的超强吸水剂,其具备优异的吸水性能和保水性能等,可以应用于多个领域。基于绿色环保理念,选用天冬氨酸作为绿色原料,合成吸水性树脂,然而单一组分的聚天冬氨酸吸水性树脂的成本较高和耐盐性较差,多种组分复合制备吸水性树脂,可以提高树脂的综合性能。因此本文以改性聚琥珀酰亚胺、丙烯酸、有机蒙脱土和羧甲基纤维素为原料采用水溶液聚合法制备了可生物降解和生物相容的复合吸水性树脂:改性聚天冬氨酸/聚丙烯酸/有机蒙脱土(KPAsp/PAA/OMMT)和改性聚天冬氨酸/聚丙烯酸/羧甲基纤维素(KPAsp/PAA/CMC)复合吸水性树脂。本文探究了两种复合树脂的合成参数、吸液动力学、pH敏感性、温度敏感性、盐敏感性以及在人工血、人工尿和乙醇水溶液中的吸液性能,并对复合树脂的结构、热稳定和表面形貌进行进行了表征,研究内容和结果如下:(1)在水溶液体系中以改性聚琥珀酰亚胺(KPSI)、丙烯酸(AA)和有机蒙脱土(OMMT)为原料,过硫酸钾(K_2S_2O_8)为引发剂,N’N-亚甲基双丙烯酰胺(MBA)为交联剂,制备了KPAsp/PAA/OMMT复合吸水性树脂。探讨了合成参数对复合树脂吸液倍率的影响,结果表明当各组分组成比为m(KPSI):m(AA)=1:3,有机蒙脱土用量为KPSI的10wt%时,蒙脱土粒径为通过网筛230~300目,AA中和度为70%,引发剂和交联剂用量分别为单体的0.5wt%和0.2wt%,反应温度为70℃,反应时间为3 h,复合树脂的吸液倍率达到最佳,其在去离子水和生理盐水中的吸液倍率分别为675 g/g和118g/g。(2)对KPAsp/PAA/OMMT复合吸水性树脂的结构,热稳定性和表面形貌进行了FTIR、XRD、TGA和SEM表征,结果表明:在蒙脱土片层之间发生了聚合交联反应,蒙脱土被剥离,达到纳米级分散;复合树脂的热稳定性得到改善,复合树脂具有均匀规则的孔道结构。复合树脂吸液动力学分析表明其吸液动力学属于菲克扩散。(3)KPAsp/PAA/OMMT复合吸水性树脂表现出良好的pH、温度、盐敏感性。复合树脂的吸液倍率在pH=6和pH=10的溶液中存在两个吸液高峰,其低临界溶解温度(LCST)是50℃,在该温度下复合树脂表现出最佳的吸液倍率,其在NaCl、CaCl_2和FeCl_3溶液中的吸液倍率均是随盐溶液浓度的升高逐渐降低,当三者浓度相同时,树脂在其中的吸液顺序为:NaClFeCl_3CaCl_2。探究了复合树脂在人工尿、人工血和乙醇水溶液的吸液倍率,结果表明:其在人工血、人工尿和50%乙醇水溶液中的吸液倍率分别达到110 g/g、46 g/g和215 g/g,是KPAsp的3.3倍、1.8倍和1.6倍。(4)采用水溶液聚合法在引发剂和交联剂作用下制备了KPAsp/PAA/CMC复合吸水性树脂,探讨了合成参数对复合树脂吸液倍率的影响,当原料组成为m(KPSI)/m(AA)/m(CMC)=1:3:0.15时,交联剂为0.1wt%,引发剂为0.5wt%,丙烯酸中和度为70%,丙烯酸质量浓度为12.5%,反应温度为70℃,合成的复合树脂在去离子水和生理盐水中的吸水倍率达到最好,分别为845 g/g和130 g/g。(5)通过FTIR、TGA和SEM对KPAsp/PAA/CMC复合吸水性树脂进行表征,结果表明复合复合树脂成功制备,热稳定性提高,孔道结构得到了改善。复合树脂吸液动力学分析表明复合树脂吸水溶胀过程属于菲克扩散。(6)探究了KPAsp/PAA/CMC复合吸水性树脂的敏感性,复合树脂在pH=5和pH=9的溶液中吸液倍率出现量高峰,表现出良好的pH敏感性;复合树脂的液倍率在55℃(低临界溶解温度)下达到最大值;在不同浓度的同种盐溶液中,复合树脂的吸液倍率随盐溶液浓度的升高而降低,当浓度相同时,树脂在不同盐溶液中的吸液大小为:NaClFeCl_3CaCl_2。在人工血、人工尿和50%乙醇水溶液中复合吸水性树脂具有良好的吸液性能,其吸液倍率分别为211 g/g、142 g/g和295 g/g,是KPAsp的6.39倍、5.68倍和2.2倍。
[Abstract]:The water-absorbent resin is an ultra-strong water-absorbing agent capable of absorbing a large amount of water, which has excellent water absorption performance and water retention property and the like, and can be applied in a plurality of fields. Based on the concept of green environmental protection, aspartic acid is used as green raw material and water-absorbent resin is synthesized, however, the cost of polyaspartic acid water-absorbent resin with single component is higher and the salt resistance is poor, and various components are compounded to prepare water-absorbent resin, so that the comprehensive performance of the resin can be improved. In this paper, the biodegradable and biocompatible composite water-absorbent resin was prepared by aqueous solution polymerization with modified polyamber acid, acrylic acid, organic montmorillonite and cellulose as raw materials. Modified polyaspartic acid/ polyacrylic acid/ organic montmorillonite (KPAsp/ PAA/ OMMT) and modified polyaspartic acid/ polyacrylic acid/ polyurethane (KPAsp/ PAA/ CMC) composite water-absorbent resin. In this paper, the synthetic parameters, the kinetics, pH sensitivity, temperature sensitivity, salt sensitivity of the two kinds of composite resins and the absorption performance of the artificial blood, artificial urine and ethanol aqueous solution were studied, and the structure, thermal stability and surface morphology of the composite resin were characterized. The research contents and results are as follows: (1) In aqueous solution system, modified polyamber (KPSI), acrylic acid (AA) and organic montmorillonite (OMMT) are used as raw materials, potassium persulfate (K _ 2S _ 2O _ 8) as initiator, N 'N-methylene bis (MBA) as cross-linking agent, KPAsp/ PAA/ OMMT composite water-absorbent resin was prepared. The effect of synthetic parameters on the rate of resin absorption was discussed. The results showed that when the composition ratio of each component was m (KPSI): m (AA) = 1: 3 and the amount of organic montmorillonite was 10wt% of KPSI, the particle size of montmorillonite was 230 ~ 300 mesh, and the neutralization degree was 70% in AA. The initiator and crosslinking agent were used in 0. 5wt% and 0. 2wt% of the monomer, the reaction temperature was 70 鈩，

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