31P核磁共振波谱表征高聚合度聚磷酸铵及其链结构  

Characterization of High Polymerization Degree Ammonium Polyphosphate and Its Chain Structure by ^(31)P NMR

作　　者：刘宜娜 杨荣杰 李定华 梁嘉香 HU Weiguo LIU Yina;YANG Rongjie;LI Dinghua;LIANG Jiaxiang;HU Weiguo(School of Materials Science and Engineering, National Engineering Research Center of Flare Retardant Materials, Beijing Institute of Technology,Beijing 100081,China;Department of Polymer&Engineering,University of Massachusetts Amherst,MA 01003,USA)

机构地区：[1]北京理工大学材料学院,国家阻燃材料工程技术研究中心,北京100081 [2]Department of Polymer Science&Engineering,University of Massachusetts Amherst,Amherst,MA 01003,USA

出　　处：《高等学校化学学报》2018年第9期2080-2088,共9页Chemical Journal of Chinese Universities

基　　金：国际科技合作与交流专项(批准号:2014DFA52900)和国家“八六三”计划项目(批准号:2013AA032003)资助.

摘　　要：以液体定量^(31)P核磁共振波谱(^(31)P NMR)为主要表征手段,通过建立水中加盐促溶的高聚合度聚磷酸铵(APP)水溶液的制备方法,研究不同溶解温度、测试温度及NMR参数等对APP聚合度的影响,建立了^(31)P NMR准确表征APP的聚合度及其链结构的方法.研究结果表明,于36℃在水中加盐溶解APP,26℃下进行^(31)P NMR测试,既保证了APP溶液良好的溶解性,又在水溶液制备和^(31)P NMR测试过程中不引起APP降解,测得的APP聚合度稳定、准确.利用液体^(31)P NMR确定了不同温度下APP盐水溶液中端基磷和中间磷弛豫时间(T_1),发现T_1与温度呈线性关系,弛豫时间参数(D_1)的设置影响APP聚合度结果,D_1设置不满足磷所需的T_1时,APP的聚合度结果偏大.^(31)P NMR表征APP链结构结果显示,APP的端基磷存在3种化学环境,而溶液离子强度和温度会影响3种端基磷的化学位移;APP的中间磷中含有H^+.此外,提出了中国化工行业标准HG/T 2770-2008中APP高聚合度测定存在的问题.Ammonium polyphosphate(APP)of high polymerization degree is an kind of important inorganic polymer flame retardant.Characterization of APP with high polymerization degree and its solution property are a meaningful topic.In this paper,quantitative liquid 31 P nuclear magnetic resonance(NMR)is used to characterize APP polymerization degree and chain structures.A method of preparing aqueous APP solution by adding NaCl in water to auxiliary dissolving was established without resulting in APP degradation.The effects of different dissolution and testing temperature,and different NMR parameters were studied on the characterization of APP polymerization degree.Finally,The method to accurately characterize the APP polymerization degree was suggested based on liquid 31 P NMR,that is:dissolving APP could be in water at 36℃with auxi-liary NaCl salt,setting the temperature as 26℃in 31 P NMR testing.In this case,the good solubility of APP could be achieved,at same time no degradation of APP happened,the measurement of APP polymerization degree can be stable and accurate.The relaxation time(T 1)of terminal phosphorus(P end)and middle phosphorus(P mid)at different temperatures were determined by liquid 31 P NMR,and the relationship between T 1 and temperature was found to be linear.The relaxation time parameter(D 1)in 31 P NMR has a great effect on the characterization of APP polymerization degree,and the polymerization degree of APP will be inaccurate when the setting of D 1 could not meet the T 1 required for phosphorus.Characterization of APP chain structures by 31 P NMR showed that there are three kinds of chemical environments in the terminal phosphorus of APP,that is the P connecting with two NH\++4,one NH\++4 and one H+,and two H+,respectively.The NaCl concentration and testing temperature obviously influence the chemical shift of terminal phosphorus in the three chemical environments.It was verified that there was the middle phosphorus connecting with H+in APP as well.

关 键 词：聚磷酸铵 聚合度 链结构 磷核磁共振 弛豫时间 

分 类 号：O631.6[理学—高分子化学]