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:杭州市浙大路38號浙大玉泉校區第十教學大樓(石化大樓)4111室
  • 郵編:310027
  • 電話:0571-87952631
  • 傳真:0571-87951612
  • Email:wulinbo@zju.edu.cn
當前位置:> 首頁 > 論文著作 > 正文
Synthesis of poly(L-lactic acid) with improved thermal stability by sulfonic acid-catalyzed melt/solid polycondensation.
作者:Bo Peng, Yutao Xu, Jijiang Hu, Zhiyang Bu, Linbo Wu*, Bo-Geng Li.
關鍵字:Biodegradable polymers, Biobased polymers, Poly(L-lactic acid), Polycondensation, Thermal stability, Nonmetallic catalyst
論文來源:期刊
具體來源:Polymer Degradation & Stability, 98 (2013), 1784-1789
發表時間:2013年
Melt/solid polycondensation (MP/SSP) is deemed as an alternative synthetic route besides ring-opening polymerization (ROP) in synthesizing poly(L-lactic acid) (PLLA). However, it is found that PLLA synthesized by MP/SSP has much poorer thermal stability than that by ROP due to more residual Sn(II) metallic catalyst in the former, but sulfonic acids does not show any detrimental effect on the thermal stability of PLLA. To synthesizing PLLA with good thermal stability by MP/SSP, a variety of commercially available sulfonic acids were screened as catalysts in MP/SSP of PLLA. Among these nonmetallic catalysts, it was found that 1,3-propanedisulfonic acid (PSA) and 1,5-naphthalene disulfonic acid (NSA) exhibited satisfactory
catalytic reactivity and PLLAs with excellent thermal stability, high molecular weight, little
coloration and good optical purity were successfully synthesized by MP/SSP. The decomposition temperature was increased by 80e100 C in comparison to SnCl2-catalyzed PLLA, and the thermal stability is  comparable to commercial PLLA produced by ROP.
主站蜘蛛池模板: 云龙县| 天镇县| 松溪县| 关岭| 宜黄县| 中西区| 丹江口市| 潍坊市| 凤庆县| 盱眙县| 崇义县| 开远市| 新化县| 黔江区| 西平县| 黎川县| 遂平县| 五莲县| 富源县| 武城县| 石屏县| 盐城市| 怀远县| 永康市| 古交市| 涡阳县| 博乐市| 托里县| 祁连县| 油尖旺区| 承德市| 扎鲁特旗| 玉林市| 石嘴山市| 南投县| 潮安县| 印江| 文成县| 福鼎市| 长乐市| 南溪县|