Crosslinking of dextran with some selective Cl-, P- and N-containing functional substances in aqueous solutions
Crosslinking of dextran with some selective Cl-, P- and N-containing functional substances in aqueous solutions
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DOI：
10.1016/s1381-5148(00)00072-9
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发表时间：
2001-02-01
影响因子：
5.1
通讯作者：
Rzaev, ZMO
中科院分区：
文献类型：
--
作者：
Güner, A;Akman, Ö;Rzaev, ZMO
葡聚糖（Dx）的交联反应（M-n为5.0 × 10（5）和2.0 × 10（6）g mol（-1））与一些选择性的含Cl-、P-和N的官能单体如环氧氯丙烷（ECH）、三氯氧磷（POCl 3）和N，N '-亚甲基双丙烯酰胺（MBAM）以及用Co-60-γ-辐照在碱性水溶液（2.8N NaOH）中在25-50 ℃下进行。确定了各体系有效溶胀和交联的最佳条件，并对溶胀初始速率等溶胀参数进行了测定（R-S，%min（-1）），交联密度（rho，g ml（-1））、平衡溶胀（S-eq，%）和交联片段的平均分子量用动力学方法和著名的Flory-Reynner方程测定了Dx/交联剂（CL）体系的M-e，g mol（-1）。观察到的这些参数的一个实质性的差异，毛皮的各种Dx/CL系统的交联剂的性质和浓度的交联和溶胀过程的机制的影响进行解释。结果表明，R-S和rho值增加，而S-eq和M-e值下降，这取决于CL的性质：伽马射线-ECH-MBAM-POCl 3. MBAM的浓度不影响初始溶胀速率，而CL的浓度对Dx/ECH和Dx/POCl_3体系的初始溶胀速率影响很大。交联聚合物的TGA分析也证实了CL的有效性。不饱和交联片段的形成，所述不饱和交联片段在u. v. -通过傅里叶变换红外（FT-IR）光谱法证实了辐照。文中还对Dx/CL体系中交联反应的一般方案和可能机理进行了描述。(C)2001爱思唯尔科技有限公司。保留所有权利。
Crosslinking reactions of Dextran (Dx) (M-n of 5.0X10(5) and 2.0X10(6) g mol(-1)) with some selective Cl-, P- and N-containing functional monomers such as epichlorohydrin (ECH), phosphorus oxychloride (POCl3) and N,N'-methylenebisacrylamide (MBAM) as well as with Co-60-gamma -irradiation were carried out in the basic aqueous solutions (2.8 N NaOH) at 25-50 degreesC. The optimum conditions of the effective swelling and crosslinking for the each system studied were found. Some swelling parameters such as initial rate of swelling (R-S, %min(-1)), crosslink density (rho, g ml(-1)), equilibrium swelling (S-eq, %) and average molecular weight of crosslinked fragments (M-e, g mol(-1)) for the Dx/crosslinker (CL) systems studied were determined by using of kinetic methods and well known Flory-Rehner equation. A substantial difference of these parameters observed fur the various Dx/CL systems was explained by the effect of nature and concentration of crosslinking agents on the mechanism of crosslinking and swelling processes. It was shown that R-S and rho values increase while the S-eq and M-e values decrease depending on the nature of CLs: in the following raw. gamma -ray-ECH-MBAM-POCl3. Concentration of MBAM does not influence the initial rate of swelling while effect of CL concentration is strongly advented in the Dx/ECH and Dx/POCl3 systems. Effectiveness of CLs is also confirmed by TGA analysis of crosslinking polymers. The formation of unsaturated crosslinked fragments, which are easily polymerized or photocyclodimerized as affected of u.v.-irradiation, was confirmed by Fourier transform infrared (FT-IR) spectroscopy. General scheme and proposed mechanism of crosslinking reactions in the Dx/CL systems was also described. (C) 2001 Elsevier Science B.V. All rights reserved.