【作者】 周发青；

【导师】 陈清松；

【作者基本信息】 福建师范大学 ， 高分子化学与物理， 2009， 硕士

【摘要】 本文对竹材的炭化机理、热处理竹材的苯甲基化改性以及热处理竹材/聚乙烯复合材料的性能三方面进行研究。将毛竹在缺氧环境下180～900℃控制炭化得到不同温度的炭化物,研究了不同炭化温度的竹炭对乙酰甲胺磷的吸附性能。将200～400℃的热处理竹材进行苯甲基化改性,利用红外光谱、元素分析、比表面积测定和X射线粉末衍射、扫描电镜等对竹材炭化物和苯甲基化热处理竹材的微观结构进行了表征分析。以HDPE为基体,以热处理竹材为填料,通过双螺杆挤出、注射成型制备热处理竹材/聚乙烯复合材料,测试了复合材料的力学性能和吸水性。通过扫描电镜和示差扫描量热法对复合材料的微观形貌和熔融、结晶行为进行分析。结果表明:(1)纤维素的链状醚键结构在250℃基本分解完全,500℃碳网开始形成,700℃碳网构造急速发达,800℃碳网的石墨化程度进一步提高。800℃炭化物的比表面积最大,为627.6 m~2/g。随着炭化温度的升高,炭化物对乙酰甲胺磷的吸附性能增强。(2)将热处理竹材进行苯甲基化改性后,纤维素晶相由纤维素Ⅰ变为纤维素Ⅱ,苯甲基化改性使热处理竹材的细胞结构变的疏松。(3)热处理竹材/聚乙烯复合材料具有与竹材/聚乙烯相当的力学强度,但它的吸水率大大降低。MAPE对复合材料的改性效果最好。在复合材料的结晶过程中,竹粉和热处理竹粉的加入使复合材料的结晶温度升高,结晶度略有降低。从实际应用及美观角度分析,200℃为竹材的最佳热处理温度,热处理时间为3 h。更多还原

【Abstract】 The study is focused on carbonization mechanism of bamboo, benzylation modification of heat-treated bamboo, the performance of heat-treated bamboo /polyethylene. A series of carbonized products of maso bamboo were prepared by controlled carbonization under hypoxia atmosphere during 180-900℃. The influencing factors on adsorption performance of the carbonized products for acephate were investigated. The benzylation of heat-treated bamboo during 200-400℃was studied. The microstructure of the carbonized products and benzylated heat-treated bamboo was characterized by FT-IR, element analysis, BET and XRD, SEM. With HDPE as Matrix, heat-treated bamboo as filler, heat-treated bomboo/polyethylene composites were prepared by means of double-screw extrusion and injection molding. The mechanical performance and water absorption properties of composites were measured. SEM and DSC were applied to analyze the microstructural aspects, melting and crystallization behavior of composites. The results showed that:(1) The chain structure of ether linkage in cellulose was destructed till 250℃, the carbon-net was formed from 500℃, further expanded rapidly at 700℃, graphitization of carbon-net was improved at 800℃. BET testing indicated that the specifia surface area of carbonized products at 800℃was 627.6 m~2/g, which was the largest among carbonized products of bamboo. As carbonized temperature increases, the adsorption abilities of bamboo charcoal for acephate becomed better.(2) Crystalling phase of cellulose in heat-treated bamboo from cellulose I transformed to II after benzylation modification. The cellular structure of heat-treated bamboo got loosened by SEM observation.(3) Comparing with bamboo/polyethylene composites, the mechanical strength of heat-treated bamboo/polyethylene composites was not reduced, but the water absorbing capacity was reduced greatly. MAPE was of the best modified effects on composites among different compatilizer. Composites showed higher crystallization temperature and lower crystallinity by comparison with HDPE matrix for the addition of bamboo and heat-treated bamboo. From the view of practical application and aesthetic, 200°C was the best heat-treated temperature for bamboo powder, the heat-treated time was 3 h.更多还原