乙二胺改性聚乳酸溶液的性质

Characteristics of EMPLA in Tetrahydrofuran(THF) by GPC-MALLS

乙二胺改性聚乳酸(EMPLA)是一种具有支化结构的新型生物材料。文中采用GPC-MALLS技术对其在四氢呋喃(THF)中的分子量、分子量分布、半径、支化及其这些量之间的相互关系进行了分析与研究,结果表明:乙二胺改性聚乳酸在四氢呋喃中的折光指数增量dn/dc值为0.052 mL/g,第二维利系数A2为3.905e-3 mol mL/g2,重均分子量-Mw为5.753e+4,重均均方根旋转半径Rw为4.5 nm,-Mw与Rw的关系式为:Rw=0.608×-Mw0.316,通过与线性聚乳酸(PDLLA)的比较,能够得到具有与PDLLA相同分子量的EMPLA有较小的均方根旋转半径的结论,并能够推出EMPLA在四氢呋喃溶液中的分子构象为球形。

Ethylenediamine-modified polylactic acid （EMPLA） is a newly synthesized polymer, the Mw, size distribution and branching property of EMPLA were analyzed by GPC-MALLS detector technology and The results show： the dn/dc value is 0.052 mL/g, the A2 value is 3.905e - 3 mol mL/g^2, the -Mw is 5.753e＋4, the Rw is 4.5 nm, and the relation of Rw and Mw is Rw=0.608 Mw^0.316,. By comparing to the linear PDLLA polymer, the branched one has a shorter RMS radius, and whose conformation in THF is inferred to be spherical shape.