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

當前位置:> 首頁 > 論文著作 > 正文
Synthesis of End-functional and Mid-functional Temperature-responsive Poly (N,N-diethyl-acrylamide) by ATRP
作者:Yue Wang, Nai-pu He*, Zhen-wu
關鍵字:Atom transfer radical polymerization, Poly(N, N-ethyl-acrylamide), Temperature-responsive
論文來源:期刊
具體來源:Acta Polymerica Sinica
發表時間:2017年

Two types of atom transfer radical polymerization (ATRP) initiators containing disulfide pyridine structure were synthesized and characterized by 1H-NMR. The results revealed that disulfide pyridine was successfully introduced to the end or the middle of the ATRP initiator molecule. N,N-diethyl-acrylamide (DEAAm) was initiated by the ATRP initiators using ATRP to prepare the end-functional (end-functional pDEAAm) and the middle-functional poly(N,N-diethyl-acrylamide) (mid-functional pDEAAm), respectively. Both the end- and mid-functional pDEAAm were characterized by 1H-NMR and gel permeation chromatography (GPC). 1H-NMR results showed that disulfide pyridine was successfully introduced into the end-group of pDEAAm chain to form theend-functional pDEAAm or the middle of the chain of pDAAm to give the mid-functional pDEAAm, respectively. GPC results showed that the molecular weight of the end-functional pDEAAm and the mid-functional pDEAAm with narrow distribution was controlled by ATRP. Polydispersity index (PDI) of the end-functional pDEAAm was 1.21, and that of the mid-functional pDEAAm was 1.23. The molecular weight of the mid-functional pDEAAm was higher than that of the end-functional pDEAAm. The results suggested that ATRP initiator with two initiating sites increased the molecular weight of the pDEAAm. Furthermore, the temperature-responsive behaviors of polymers in the aqueous solutions were tested by UV-visible spectrophotometer. Both types of pDEAAms showed excellent temperature-sensitivity in aqueous solution. The lower critical solution temperature (LCST) of the pDEAAms was identified as 28℃. Below the LCST, pDEAAms were completely dissolved in water. In contrast, above the LCST of pDEAAms, phase separation appeared in the polymers aqueous solutions. The position of disulfide pyridine structure in pDEAAms chain did not influence the temperature-responsive behavior of the polymers aqueous solutions. Both pDEAAm are expected to be useful to prepare block copolymers and to bind site-specifically to biomacromolecules. In particular, the mid-functional pDEAAm will be useful to prepare the star-polymers and the multi-armed polymers.

主站蜘蛛池模板: 涿州市| 勃利县| 黄梅县| 汝阳县| 抚松县| 府谷县| 乐山市| 乌拉特前旗| 思茅市| 安图县| 广宁县| 铁力市| 乐亭县| 瑞昌市| 叙永县| 玛曲县| 类乌齐县| 涿鹿县| 宿迁市| 临邑县| 申扎县| 周至县| 延长县| 丹凤县| 名山县| 广州市| 墨脱县| 临泉县| 孝感市| 哈密市| 林州市| 陕西省| 淳安县| 甘南县| 广平县| 怀化市| 临高县| 扎囊县| 绵阳市| 岱山县| 南京市|