Swelling Properties of New Hydrogels Based on the Dimethyl Amino Ethyl Acrylate Methyl Chloride Quaternary Salt with Acrylic Acid and 2-Methylene Butane-1,4-Dioic Acid Monomers in Aqueous Solutions

Hydrogels of dimethylaminoethyl acrylate methyl chloride quaternary salt (Q9) have been synthesized with different monomer ratio by copolymerization of this poorly studied monomer either with acrylic acid or with 2-methylene bu-tane-1,4-dioic acid. Hydrogel swelling was measured as a function of the composition of the hydrogel and of the crosslinking agent ratio. High values of swelling have been obtained at very high crosslinking values (【14 wt %) and the equilibrium swelling was reached at very low time (less than 15 minutes). The swelling isotherms consisted of a steep initial portion and then levelled off as asymptotically to the equilibrium swelling limit. The experimental data suggest clearly that the swelling process obeys second-order kinetics. According to this, the kinetics rate constant and the equilibrium water content were determined at different comonomer composition and crosslinker concentration. The calculated kinetic constants ranged from 0.48 to 3.76 ×10-2 min-1 for poly (acrylic acid-co-Q9) hydrogels and from 0.68 to 4.0 ×10-2 min-1 for poly (2-methylene butane-1,4-dioic acid-co-Q9) hydrogels depending on the hydrogels composition. The diffusion process was evaluated for each hydrogel showing a non-Fickian type diffusion. In all cases was observed a considerable increase in diffusion coefficient as Q9 content increases.

红花八角茎叶的化学成分研究

目的研究红花八角Illicium dunnianum干燥茎叶的化学成分。方法综合应用HP-20、硅胶、ODS、Sephadex LH-20和半制备液相等多种色谱学方法进行分离纯化,并根据化合物的理化性质和核磁共振波谱数据进行结构鉴定。结果从红花八角叶干燥茎叶部分70%乙醇提取物中分离得到12个化合物,分别鉴定为反-8-羟基-2,7-二甲基-4-葵烯-1,10-二羧酸(1)、(2E,4E)-8-hydroxy-2,7-dimethyl-decadien-(2,4)-disaeure-(1,10)-dioic acid(2)、2,7-dimethyl-4-octenedioicacid(3)、2,7-dimethyl-2,4-octadienedioic acid(4)、二氢山柰酚(5)、牡荆素(6)、槲皮素3-O-β-D-半乳糖苷(7)、山柰酚3-O-β-D-葡萄糖基-6′′-α-L-鼠李糖苷(8)、水仙苷(9)、菜豆酸(10)、川芎内酯I(11)、脱落酸(12)。结论化合物1为新的类胡萝卜素衍生物,命名为八角葵烯二酸;化合物9、10为首次从该植物中分离得到;化合物2~4、11为首次从八角属植物中分离得到。