私密直播全婐app免费大渔直播,国产av成人无码免费视频,男女同房做爰全过程高潮,国产精品自产拍在线观看

相關鏈接
聯系方式
  • 通信地址:上海市松江區人民北路2999號, 東華大學 材料學院C565
  • 郵編:201620
  • 電話:021-67792954
  • 傳真:021-67792955
  • Email:zyp@dhu.edu.cn
當前位置:> 首頁 > 論文著作 > 正文
Studies on the synthesis and thermal properties of copoly(L-lactic acid/glycolic acid) by direct melt polycondensation
作者:Ping Lan, Yaopeng Zhang, Qinwei Gao, Huili Shao, Xuechao Hu
關鍵字:lactic acid/glycolic acid,melt polymerization,copolymerization, thermal properties,solubility
論文來源:期刊
具體來源:JOURNAL OF APPLIED POLYMER SCIENCE
發表時間:2004年

A two-step direct copolymerization process of L-lactic acid (L-LA)/glycolic acid (GA) was developed. The first step was to produce an oligomer of L-LA/GA and then the oligomer was polymerized with binary catalyst tin chloride dihydrate/rho-toluenesulfonic acid. In this way, the copoly(L-LA/GA) (PLGA), without any organic solvent, was synthesized directly. The thermal properties and solubility in chloroform of PLGA were studied by DSC and NMR. The results showed that the melting point of PLGA decreases with increasing mole fraction of GA units in copolymer. In addition, the melting point of polymer also decreased with increasing degree of racemization of polymer. The solubility of PLGA in chloroform decreased with the increase of the average lengths of the glycolic acid units. (C) 2004 Wiley Periodicals, Inc.

主站蜘蛛池模板: 阿拉善左旗| 河北省| 驻马店市| 商都县| 郧西县| 渭南市| 镶黄旗| 满洲里市| 临沂市| 南岸区| 眉山市| 墨竹工卡县| 行唐县| 玉树县| 同德县| 呼图壁县| 贺兰县| 玛沁县| 河源市| 云梦县| 广饶县| 万载县| 登封市| 巴彦淖尔市| 穆棱市| 乐东| 沙湾县| 泾川县| 大渡口区| 宝丰县| 朝阳县| 阿合奇县| 射洪县| 南康市| 黑龙江省| 稷山县| 施甸县| 从化市| 扬中市| 阿克陶县| 民县|