半纤维素的提取及其温敏性水凝胶的制备

以采用稀碱抽提法从植物残料中提取的半纤维素为原料,通过化学交联法,自由基聚合将单体接枝到半纤维素链上,并交联温敏性单体,促使形成共聚交联网络结构,得到温度敏感性水凝胶。通过物理交联法,半纤维素与壳聚糖物理交联,制备半纤维素基水凝胶。采用交联度测定、溶胀动力学研究、红外光谱、差示量热等手段对化学交联和物理交联两种方法制得的半纤维素基水凝胶温度响应性能进行表征。结果表明:10%NaOH提取的半纤维素得率最高;化学交联法和物理交联法制得的半纤维素基水凝胶,都具有温度负响应特性,为温敏性水凝胶。作为当下较为热门材料,广泛应用于医疗、农业和生物组织工程材料等领域。

Extraction of hemicellulose and the preparation of temperature sensitivity hydrogel

Hydrogels are three-dimensional(3D)cross-linked networks(formed by chemical and physical methods)of hydrophilic polymers,usually capable of absorbing water and swelling.Hemicellulose is the most abundant,renewable and inexpensive hydrophilic polymer,which provides adequate solutions for increasing environmental concerns,taking advantage of biocompatibility and biodegradability.The hemicellulose was extracted from various plant residues by dilute alkali extraction.Through the chemical cross-linking method,the temperaturesensitive monomer was grafted onto the hemicellulose chain by radical polymerization to promote the formation of a copolymerized cross-linked network structure,and obtained a temperature-sensitive hydrogel.Another strategy was the physical crosslinking approach,which prepared hemicellulose-based hydrogels through physical crosslinking of hemicellulose and chitosan.The temperature response properties of hemicellulose-based hydrogels prepared by chemical crosslinking and physical crosslinking methods were characterized by crosslinking degree determination,swelling kinetics,fourier transformed infrared(FT-IR),differential scanning clorimetry(DSC),respectively.The results shown that the yield of hemicellulose extracted by 10%NaOH was the highest.The hemicellulose-based hydrogels prepared by the chemical crosslinking and the physical crosslinking methods had negative temperature response characteristics,and were temperature-sensitive hydrogels.This temperature-responsive hemicellulose-based hydrogel was currently a popular material,and expected to be used in medical,agricultural,biological tissue engineering materials and other fields.