权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Synthesis of hydrophobic-hydrophilic gradient gel and its application

疏水-亲水梯度凝胶的合成及其应用

基本信息

批准号：
08651053
负责人：
IIZAWA Takashi
金额：
$ 1.47万
依托单位：
HIROSHIMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08651053/
关键词：
Esterification Poly (acrylic acid) gel Core-shell typed gel Gel capsule Reaction analysis Materials for slow chemical release 疎水化

项目摘要

This study reports novel synthetic of hydrophobic-hydrophilic gradient gradient gel by the esterification of outer DBU salt of poly (acrylic acid) gel (DAA) with alkyl halide to give new amphiphilic core-shell typed gel which is poly (acrylic acid) gel covered and bound chemically with hydrophobic shell layr. When the gel was placed in an aprotic polar solvent containing excess alkyl halide, swelling occurred and the gel was divided into a swollen shell and an unswollen core. When R and r are radius of shell and core after t min, respectively, the apparent ratio of reacted gel to the original gel was determined as function of r/R.The rection was followed as a function of r/R and analyzed kinetically using homogenous model. The overall reaction consisted of rates of diffusion of alkyl halide through swollen shell, esterification, and diffusion of alkyl halide through unswollen core. There are three rate-controlling steps ; diffusion through swollen shell control, esterification control, diffusion through unswollen core control. The reaction was affected markedly by readctivity and bulkiness of alkyl halide. Furthermore, the thermal acid-catalyzed deesterification of poly (t-butyl methacrylate) gel from the inner gives similar core-shell typed gel. We prepared gel casules based on this background. When the gel capsules containing chemicals were dipped in solution, the release of chemical took place with swelling the gels. This results suggested that the chemical release from the gel capsule controlled by the thickness of the shell layr and chemical structures. Therefore, the obtained gel capsule is useful for control release.

本文报道了一种新型的疏水-亲水梯度凝胶的合成方法，即通过聚丙烯酸凝胶（DAA）的外层DBU盐与卤代烷的酯化反应，合成了一种新型的两亲性核壳型凝胶，即聚丙烯酸凝胶与疏水壳层的包覆和化学键合。当凝胶被放置在含有过量烷基卤的非质子极性溶剂中时，发生溶胀，并且凝胶被分成溶胀的壳和未溶胀的核。当R和r分别为t min后壳和核的半径时，反应凝胶与原始凝胶的表观比率作为r/R的函数被确定。反应作为r/R的函数被跟踪，并使用均相模型进行动力学分析。整体反应由卤代烷通过溶胀壳、酯化和卤代烷通过未溶胀核的扩散速率组成。有三个速率控制步骤：通过溶胀壳控制的扩散，酯化控制，通过未溶胀核控制的扩散。卤代烷的活泼性和体积对反应有显著影响。此外，聚甲基丙烯酸叔丁酯凝胶的热酸催化脱酯从内部得到类似的核壳型凝胶。我们在此背景下制备了凝胶胶囊。当含有化学物质的凝胶胶囊浸入溶液中时，化学物质的释放伴随着凝胶的溶胀而发生。结果表明，壳层厚度和化学结构是控制药物释放的主要因素。因此，所获得的凝胶胶囊可用于控制释放。