戊二醛交联前后明胶微球热转变研究

在空气和氮气气氛中,对未交联的明胶微球(GMs)和戊二醛交联明胶微球(CGMs)进行了受热转变研究,并利用250℃热处理的明胶球制备出具有多孔内核的明胶基结构.经过热重分析(TGA)、差示扫描量热法(DSC)、扫描电子显微镜(SEM)和付里叶变换红外光谱(FTIR)等分析测试表明:戊二醛交联明胶微球300℃后热失重略大于未交联明胶微球,两者的熔化温度Tm都为228℃;在空气中250℃热处理7 h的未交联明胶微球经过稀硫酸处理后可以得到多孔内核结构,多孔内核含碳、氧元素,外壳以碳元素为主;105℃和190℃热处理的明胶球化学成分基本相同,250℃热处理使明胶分子中的酰胺键减少、并发生三级结构的转变.

Thermal Transition of Gelatin Microspheres with and Without Glutaraldehyde-Crosslinking

Thermal transition of gelatin microspheres(GMs) and glutaraldehyde-crosslinked gelatin microspheres(CGMs) in both air and nitrogen atmosphere were studied in this paper,and gelatin-based materials with porous core were produced from GMs heat-treated at 250 ℃.The specimens were characterized by the thermal gravimetric analysis(TGA),differential scanning calorimetry(DSC),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS) and fourier transform infrared spectroscopy(FTIR).It was found that CGMs had an equal slight weight loss more than GMs from 300 ℃ in either air or nitrogen atmosphere,and the melting temperature(Tm) of GMs and CGMs are both at 228 ℃.A foam-like core/solid shell structure was formed from acid-treating GMs which were heat-treated for 7 h in air,and the dominant elements of the core are carbon and oxygen while the shell consists of carbon.GMs had not undergone any chemical reaction by heat-treating at 105 and 190 ℃.Heat-treating at 250 ℃ caused the amount decreasing of amide bond and tertiary structure transformation in gelatin molecule.