甜菊糖苷提取中脱盐脱色树脂的选择及流速对收率的影响

甜菊糖苷的工业提取中,通常以三氯化铁或硫酸亚铁为絮凝剂,对提取液进行絮凝处理。为提高后续吸附树脂的吸附量,改善产品品质,在大孔吸附树脂吸附前,对絮凝液进行脱盐脱色是至关重要的。通过对阳离子树脂001×7、001×14.5、001×16,与阴离子树脂330和D941相互组合,考察了不同组合下脱盐脱色的效果,以及不同流速对甜菊糖苷收率的影响。结果表明,选用阳离子树脂001×14.5与阴离子树脂D941相组合进行脱盐脱色,效果较好,且甜菊糖苷收率可达96.46%;脱盐脱色流速控制在3～4BV/h最佳。     

干粉浸提法提取菊粉及树脂脱色工艺研究

采用干粉浸提法从干燥的菊芋颗粒中提取菊粉,石灰-磷酸法除杂,得到澄清的菊粉提取液;利用脱色一号、D280、D296R、D301-G、201-7 5种阴离子树脂和AB-8大孔吸附树脂分别对菊粉提取液进行脱色处理,结果表明,D280型树脂脱色效果最好,综合评分值最高为80.31%,脱色率为84.67%,菊粉保留率为75.9%。通过响应曲面实验探讨菊粉澄清液的pH、质量浓度和温度对综合评分值的影响,并对这3个因素进行了优化。确定树脂脱色的最佳条件为pH=5.11,质量浓度为103.6 g/L,温度为25.43℃。在此条件下综合评分值为95.10%。     

交联聚丙烯酰多胺树脂的合成及脱色性能的研究

以二乙烯苯，甲基丙烯酸甲酯为共聚单体，以不同结构的多乙烯多胺为胺化试剂，合成了一系列大孔交联聚丙烯酰多胺树脂。测定了树脂孔的结构参数和功能基的含量，并考查了此类树脂对甜菊甙的脱色性能。     

树脂材料在烷基多苷脱色技术中的应用

采用弱碱阴离子交换树脂,研究淀粉糖苷表面活性剂的动态吸附脱色,脱色后产品稳定性好、透明度高、不产生不愉快气味、无机盐含量低、操作简单、脱色时间短、易再生。在470 nm波长下吸光度为0.058,强化实验72h吸光度为0.051。红外光谱和气相色谱分析证明脱色前后烷基多苷结构基本不变化。     

大孔吸附树脂对维生素C脱色研究

通过比较树脂的脱色效果、脱色条件、树脂再生方法对多种树脂进行了筛选实验.结果显示,D 201吸附树脂脱色性能良好,再生使用次数多,回收率稳定,适合维生素C交换液的脱色,确定了最佳实验条件.与传统工艺相比,树脂脱色工艺具有生产简单、环境污染小等优点.     

大孔聚苯乙烯吸附树脂对鳕鱼排免疫活性肽的脱盐

比较了6种聚苯乙烯型大孔树脂对鳕鱼排活性肽的吸附能力,并研究了各因素(温度、pH、吸附物浓度、料液比等)对树脂吸附特性的影响. 通过动态吸附与解析实验,探讨了DA201-C树脂对鳕鱼排活性肽脱盐的可行性. 结果表明,DA201-C树脂对鳕鱼排活性肽吸附能力最强,在温度25℃、pH 4.0、溶液浓度10 mg/mL、料液比(树脂质量与活性肽体积比)2 g/mL的条件下,吸附率最高为84.7%. 在动态吸附解析实验中,多肽的脱盐率为98.1%,回收率为90.3%. 且脱盐后的多肽同样具有促进脾细胞增殖活性且呈剂量依赖关系.     

丙烯酸类树脂脱色性能的研究

利用胺解法对丙烯酸类树脂进行脱色性能的研究,结果发现,树脂的交换容量对丙烯酰胺阴离子交换树脂的脱色性能有较大影响,因此要想得到较好的脱色效果,必须保证树脂具有较高的交换容量.在4种功能基类型中,以四乙烯五胺的树脂脱色效果最好.     

1，3-丙二醇发酵液脱盐用离子交换树脂的筛选

研究了用离子交换树脂处理1,3-丙二醇发酵液,选用6种阳离子交换树脂和3种阴离子交换树脂,以交换容量、电导率和再生时间为指标,考察了树脂的脱盐效果。结果表明：阳离子交换树脂中的D001-cc对1,3-丙二醇发酵液的处理效果最好,150mL树脂的平均交换容量达到240mL,电导率能降到2250gS／cm,再生时间7h;3种阴离子交换树脂中,D301R的去盐效果最好。     

不同氧化性的盐酸对树脂再生的影响

纯盐酸不具有氧化性,然而由于盐酸制造工艺的不同,通常会使工业盐酸具有一定的氧化性,这将会导致阳树脂在再生中受到氧化而遭受破坏,从而影响纯水的制造质量。经过实验证实了以上事实并且提出了一些解决方案。     

The Effect of Superimposed Dynamic and Static Stresses on the Stress Relaxation Rates of Model Epoxy Resins

Model epoxy resins with controlled crosslinking densities were prepared from a commercially available DGEBA (Epon Resin 825® from Shell Chemical) and α,ω-aliphatic diamines having different lengths of the aliphatic chain. The mixtures were always prepared in stoichiometric ratio. Dumbbell specimens, either with a cylindrical (with thin walls) or a rectangular cross section, have been subjected to combined static tensile strains (applied vertically) and dynamic torsional strains (applied horizontally). The experiments were performed at temperatures encompassing the glassy and the rubbery range of each investigated resin. The apparatus, by which the combined dynamic and static stresses were applied, was equipped with load cells for measurement of stresses developed in the specimens, both in tension and in shear. In this paper, results concerning the effect of the above combinations of stresses on stress relaxation rates in tension are shown. The main conclusion of this study is that combinations of dynamic and static stresses affect the network chain mobility, as it is expressed by the stress relaxation rate, in a way depending on temperature and frequency of torsional oscillations, as well as the crosslinking density of the polymer. For the most flexible epoxy resins investigated in this work, the superimposed stressing experiments led to a stiffening of the structure in the glassy state, while an opposite effect has been observed for the most rigid resins in similar conditions. It seems that the behavior of the investigated epoxy resins in complex fields of stresses is governed by a balance between two competitive processes: free volume increase (by a strain-induced dilatation mechanism), and physical aging and short range orientation.