摘要
首先制备了环氧氯丙烷交联的玉米淀粉,然后经稳定化和炭化得到淀粉基类球形炭材料。通过TG-MS分析玉米淀粉在环氧氯丙烷影响下的热解行为;采用扫描电镜(SEM)、X射线粉末衍射仪(XRD)对淀粉基类球形炭材料的微观形貌和晶型结构进行表征;利用原位红外(in situ FTIR)对淀粉热解过程中表面化学演化进行表征;最后,通过以上表征及分析探究环氧氯丙烷对淀粉热解行为的影响并深入探究了环氧氯丙烷与淀粉的交联反应机理。结果表明,淀粉交联环氧氯丙烷后,热稳定性得到有效提高,最大热失重温度提前,热解过程相对温和,避免淀粉在剧烈反应时基本骨架结构遭到破坏和炭收率显著降低,同时,交联淀粉在后续的热解过程中更趋向于向芳香族结构转化,在相同温度下比纯淀粉热解产物炭化程度高,得到的最终产物炭收率高;环氧氯丙烷与淀粉在热解过程中与淀粉发生交联反应,形成稳定的网状结构稳定淀粉炭骨架从而减少淀粉中挥发性小分子物质的产生。
Crosslinking is a common method for preparing biomass-based carbon materials.Corn starch grafted with epichlorohydrin was prepared and then stabilized and carbonized to obtain starch-based near-spherical carbon materials.The pyrolysis of corn starch under the influence of epichlorohydrin was analyzed by TG-MS,and the micro-morphology and crystal structure of the near-spherical carbon materials were characterized by SEM and XRD.The surface chemical evolution of the starch before and after pyrolysis was characterized by in-situ FTIR.The modified starch pyrolysis and the cross-linking reactions between epichlorohydrin and starch were investigated.Results indicate that for the modified starch the temperature at which the weight loss rate is a maximum is lowered so that the pyrolysis is relatively mild,and the destruction of the basic skeleton is reduced and the carbon yield greatly increased compared with pristine starch.The cross-linked starch tends to transform to aromatic structures in pyrolysis,the carbonization degree of the hydrolysate is improved,and the yield of the final product is increased compared to the non-crosslinked material.During pyrolysis,epichlorohydrin cross-links with starch to form a network structure,which stabilizes the starch skeleton,thus reducing the production of volatile small molecules.
作者
李茂群
陈成猛
孙国华
谢莉婧
LI Mao-qun;CHEN Cheng-meng;SUN Guo-hua;XIE Li-jing(CAS Key Laboratory of Carbon Materials,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《新型炭材料》
SCIE
EI
CAS
CSCD
北大核心
2020年第4期452-458,共7页
New Carbon Materials
基金
中国科学院洁净能源创新研究院合作基金项目资助(DNL180308)
山西省重大专项(MC2016-08)
山西省重大专项(MC2016-04).
关键词
玉米淀粉
环氧氯丙烷
类球形炭材料
热解
交联机理
Corn starch
Epichlorohydrin
Near spherical carbon materials
Pyrolysis
Crosslinking mechanism
