Chemical modification of shaped hydrogels in non-aqueous medium
    1.
    发明授权
    Chemical modification of shaped hydrogels in non-aqueous medium 失效
    非水介质中形状水凝胶的化学改性

    公开(公告)号:US5530111A

    公开(公告)日:1996-06-25

    申请号:US296171

    申请日:1994-08-29

    CPC分类号: C08B3/00 C08B3/14

    摘要: A method is described for the chemical modification of pre-shaped hydrogels in non-aqueous medium. The conditions permit the reaction of highly expanded, porous hydrogel particles, such as spherical beads, using pseudo homogeneous reaction conditions in the absence of water. The method involves a three step procedure in which the porous gels are solvent exchanged int a water-free solvent (step 1) with minimal change in gel dimension and porosity; followed by reaction under non-aqueous condition (step 2); and followed by solvent exchange into water (step 3). Many different types of reactions requiring non-aqueous conditions may be carried out using these conditions. The method has particularly been demonstrated for crosslinking fluorinating beads, and for esterifying beads in a reaction involving multifunctional free carboxylic acids in the presence of dicyclohexylcarbodiimide (DCC).

    摘要翻译: 描述了一种用于非水介质中预形状水凝胶的化学改性的方法。 该条件允许在不存在水的情况下使用假均匀反应条件使高度膨胀的多孔水凝胶颗粒如球形珠的反应。 该方法涉及三步法,其中多孔凝胶在无水溶剂(步骤1)中溶剂交换,凝胶尺寸和孔隙率变化最小; 然后在非水条件下反应(步骤2); 然后进行与水的溶剂交换(步骤3)。 可以使用这些条件进行需要非水性条件的许多不同类型的反应。 特别是在二环己基碳化二亚胺(DCC)的存在下,涉及氟化珠的交联以及涉及多官能游离羧酸的反应中的酯化珠粒的方法。

    Chitin-based coatings
    3.
    发明授权
    Chitin-based coatings 失效
    甲壳质基涂料

    公开(公告)号:US5900479A

    公开(公告)日:1999-05-04

    申请号:US435866

    申请日:1995-05-05

    IPC分类号: C08B37/08 C09D105/08 D01F9/00

    摘要: A chitosan starting material is combined with a dilute organic acid to produce a chitosonium ion complex. The chitosonium ion complex is then cast, sprayed, extruded, or otherwise processed to produce filaments, coatings, fibers, or the like. Heat is then used to convert the chitosonium ion complex into a N-(C.sub.1-30)acyl glucose amine polymer.

    摘要翻译: 将壳聚糖起始材料与稀有机酸组合以产生壳聚糖离子络合物。 然后将壳聚糖离子络合物浇铸,喷雾,挤出或以其它方式加工以生产细丝,涂层,纤维等。 然后使用热将壳寡糖离子络合物转化成N-(C1-30)酰基葡萄糖胺聚合物。

    Cellulose derivatives with a low degree of substitution
    5.
    发明授权
    Cellulose derivatives with a low degree of substitution 失效
    具有低取代度的纤维素衍生物

    公开(公告)号:US5523398A

    公开(公告)日:1996-06-04

    申请号:US296934

    申请日:1994-08-31

    CPC分类号: C08B3/10 C08B3/02

    摘要: The invention is directed to the formation of cellulose derivatives using homogenous phase reaction conditions. Cellulose is dissolved using DMAc/LiCl and a reagent system is added to promote the acylation of an appropriate acid anhydride or free carboxylic acid. One reagent system includes N,N-dicyclohexylcarbodiimide (DCC) and 4-pyrrolidinopyridine (PP). Another reagent system includes p-toluene sulfonyl chloride (TsCl) and pyridine (Py).

    摘要翻译: 本发明涉及使用均相相反应条件形成纤维素衍生物。 使用DMAc / LiCl溶解纤维素,并加入试剂体系以促进合适的酸酐或游离羧酸的酰化。 一种试剂系统包括N,N-二环己基碳二亚胺(DCC)和4-吡咯烷基吡啶(PP)。 另一试剂系统包括对甲苯磺酰氯(TsCl)和吡啶(Py)。