【作者】 孙勇；

【导师】 李凤红；

【作者基本信息】 沈阳工业大学 ， 化学工艺， 2013， 硕士

【摘要】 壳寡糖是一种具有良好的生物相容性、生物降解性和生物活性的天然高分子。聚己内酯是一种具有优越的生物降解性、生物相容性和药物通透性的合成高分子。将壳寡糖和聚己内酯用于制备新型的壳寡糖基生物材料，具有重要的科学参考价值和巨大的应用前景，将在生物医用降解材料、药物控释载体和组织工程材料等方面获得应用。主要内容和研究成果如下：1.以N, N二甲基甲酰胺（DMF）为溶剂，邻苯二甲酸酐直接与壳寡糖的氨基反应，制备了邻苯二甲酰化壳寡糖前驱体（PHCSO）。结果表明：PHCSO在DMF、DMSO和吡啶中具有较好的溶解性；XRD和DSC分析表明PHCSO改变了壳寡糖的分子结构，形成了新的结晶结构；TGA分析表明PHCSO的热降解温度高于壳寡糖；SEM分析表明PHCSO的表面结构发生变化，由壳寡糖的圆球体变为片状体。2.以辛酸亚锡为催化剂，分别通过直接法—ε-己内酯（ε-CL）开环聚合接枝PHCSO和间接法—羧酸官能化聚己内酯与PHCSO反应制备了邻苯二甲酰化壳寡糖接枝聚己内酯（PHCSO-g-PCL），可实施壳寡糖在羟基上的定位接枝改性。结果表明：随着ε-CL与PHCSO配比的增加，接枝率提高；GPC证实了间接法制备的接枝物分子量分布窄；DSC分析表明PHCSO-g-PCL（ε-CL为4ml）具有热塑性，熔点为55.82℃；TGA分析表明PHCSO-g-PCL的热稳定性很高，PHCSO-g-PCL（ε-CL为4ml）的热分解温度为265℃；XRD分析表明PHCSO-g-PCL是一种结晶性接枝物。3.采用1-乙基-3-（3-二甲基氨丙基）碳二亚胺盐酸盐（EDC·HCl）作活化剂，以PHCSO为前驱体，与MPEG-b-PCL-COOH嵌段共聚物反应合成了热塑性PHCSO-g-PCL-b-MPEG共聚物，这种接枝反应路线不仅可实施壳寡糖的定位接枝改性，还可实现分子量可控，接枝位点可控。~1H NMR分析表明随着ε-CL量的增加，MPEG-b-PCL的分子量逐渐增大；GPC分析表明MPEG-b-PCL，MPEG-b-PCL-COOH和PHCSO-g-PCL-b-MPEG分子量分布均较窄；DSC和TGA分析表明MPEG-b-PCL、MPEG-b-PCL-COOH和PHCSO-g-PCL-b-MPEG的结晶度和热降解温度均逐渐降低。4.采用溶液法制备了二元共混物（PHCSO-g-PCL/PCL），其质量配比分别为0:100、10:90、20:80、30:70、40:60、50:50和100:0。将LDPE与配比为40:60的二元共混物进行熔融共混，制备可降解共混材料LDPE/PHCSO-g-PCL/PCL，质量配比（LDPE/二元共混物）分别为100:0、95:5、90:10、85:15和80:20。DSC分析表明当PHCSO-g-PCL/PCL的配比为40:60时，二元溶液共混物的相容性最好；力学性能测试分析表明随着PHCSO-g-PCL/PCL加入量的增大，可降解共混材料LDPE/PHCSO-g-PCL/PCL的拉伸强度有所提高，断裂伸长率降低，当LDPE/二元溶液共混物为85:15时，拉伸强度和断裂伸长率均达到最高；TGA分析表明随着PHCSO-g-PCL/PCL组分含量的增加，LDPE/PHCSO-g-PCL/PCL共混材料的热降解温度逐渐降低。更多还原

【Abstract】 Chitosan oligosaccharide (CSO) is a kind of natural polymer with goodbiodegradability, biocompatibility and bioactivity. Polycaprolactone (PCL) is a kind ofsynthetic polymer with excellent biodegradability, biocompatibility and drug permeability.Biological materials based on CSO were prepared with CSO and PCL, they will be ofimportant scientific reference value and great application prospect, and they should beapplicable for biodegradable medical material, drug delivery carrier and tissue engineering.The main contents and results list below:1. Phthaloyl chitosan oligosaccharide precursor (PHCSO) was prepared through thereaction of Phthalic anhydride with the amino group of CSO in a solvent of N, N dimethylformamide (DMF). The results showed that the solubility of PHCSO had been improved inDMF, DMSO and Pyridine. XRD and DSC indicated that PHCSO changed the originalcrystal structure of CSO, and formed a new type of crystal structure. TGA indicated thatthe decomposition temperature of PHCSO was higher than that of CSO. SEM indicatedthat the ball structure of CSO had been changed and the surface morphology of PHCSObecame lamellar.2. The phthaloyl chitosan oligosaccharide-g-polycaprolactone (PHCSO-g-PCL) wassynthesized by coupling the hydroxyl group using direct method via the ring-opening graftcopolymerization of ε-caprolactone onto the backbone of PHCSO and indirect method ofacid functional group of PCL reacting with PHCSO in the presence of stannous octoatecatalyst. The regioselective graft modification of CSO could be done through this methodof graft polymerization. It was found that the graft content of PCL in the graft copolymerincreased with increasing the mole ratio of ε-caprolactone to PHCSO. GPC confirmed themolecular weight distribution by indirect method was narrow. DSC results showed thatPHCSO-g-PCL (4ml ε-CL) was thermoplastic, its melting temperature was58.82℃. TGAanalysis showed that the thermoplastic graft copolymer had a high thermal stability, Thetemperature at5%weight loss of PHCSO-g-PCL (4ml ε-CL) was265℃. XRD analysisshowed that PHCSO-g-PCL was a crystalline graft copolymer. 3. A kind of thermoplastic copolymer of PHCSO-g-PCL-b-MPEG was synthesizedusing EDC·HCl as an activator, PHCSO as precursor and MPEG-b-PCL-COOH blockcopolymers. The grafting reaction route could not only implement the regioselective graftmodification of CSO, but also realizing the control of molecular weight and graft site.1HNMR indicated that molecular weight of MPEG-b-PCL block copolymer increased withthe increasing of the mole ratio of ε-caprolactone. GPC confirmed that the molecularweight distribution of MPEG-b-PCL, MPEG-b-PCL-COOH and PHCSO-g-PCL-b-MPEGwere narrow. DSC and TGA results showed that the crystallinity and thermal degradationtemperature of MPEG-b-PCL, MPEG-b-PCL-COOH and PHCSO-g-PCL-b-MPEG wereboth decreased gradually.4. PHCSO-g-PCL/PCL binary blends were prepared using solution blending, theirweight ratio were0:100、10:90、20:80、30:70、40:60、50:50and100:0, respectively.Biodegradable blending materials of LDPE/PHCSO-g-PCL/PCL were prepared using meltblending with LDPE and PHCSO-g-PCL/PCL of quality ratio (40/60), their weight ratiowere100:0、95:5、90:10、85:15and80:20. DSC showed that the compatibility of binarysolution blends (PHCSO-g-PCL/PCL) was the best when its weight ratio was40:60; Themechanical property test showed that the tensile strength of biodegradable blendingmaterials of LDPE/PHCSO-g-PCL/PCL increased with increasing the content ofPHCSO-g-PCL/PCL, however the elongation at break decreased, When the weight ratio ofLDPE/binary blends was85:15, tensile strength and elongation at break were the highest.TGA analysis showed that the thermal degradation temperature ofLDPE/PHCSO-g-PCL/PCL blending materials gradually reduced with increasing thecontent of PHCSO-g-PCL/PCL.更多还原