DOPO衍生物/聚乳酸复合材料的热降解、阻燃及力学性能  

Thermal degradation,flame retardancy and mechanical properties of DOPO derivatives/poly(lactic acid)composites

作　　者：徐文静 龙丽娟[2] 徐国敏 黄绍文[2] 向宇姝 李娟[2] 秦舒浩[2] 何敏[1] 于杰[1,2] XU Wenjing;LONG Lijuan;XU Guomin;HUANG Shaowen;XIANG Yushu;LI Juan;QIN Shuhao;HE Min;YU Jie(College of Materials and Metallurgy,Guizhou University,Guiyang 550025,China;National Engineering Research Center for Compounding and Modification of Polymer Materials,Guiyang 550014,China)

机构地区：[1]贵州大学材料与冶金学院,贵阳550025 [2]国家复合改性聚合物材料工程技术研究中心,贵阳550014

出　　处：《复合材料学报》2021年第9期2841-2854,共14页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51463006);黔科合成果(项目号[2018]4210);白科合同(项目号[2019]15);黔科合平台人才([2019]5632号)。

摘　　要：研究9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)、10-(2,5-二羟基苯基)-10-氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO-HQ)、6H-二苯并[c,e][1,2]氧代磷酸甘油酯,6,6’-(1,2-苯乙基)双-,66’-二氧化物(DiDOPO)三种衍生物的热分解行为,并考察了它们对聚乳酸(PLA)材料热降解、阻燃及力学性能的影响。热重分析结果表明,DOPO阻燃剂初始分解温度(T_(5%))仅为154℃,DOPO-HQ的T_(5%)提高到342℃,DiDOPO的T_(5%)达到363℃,明显高于DOPO与DOPO-HQ。对比DOPO衍生物/PLA复合材料的T_(5%)发现,T_(5%)(DOPO/PLA,273.5℃)<T_(5%)(DOPO-HQ/PLA,321.5℃)<T_(5%)(DiDOPO/PLA,333.8℃),呈现出与阻燃剂热稳定性相一致的递增趋势。另外,热降解动力学结果表明复合材料的热降解活化能提高。通过热重-红外光谱分析(TGIR)、裂解-气相色谱/质谱联用(PY-GC/MS)探究DOPO衍生物/PLA复合材料的热降解行为,结果表明三种阻燃剂主要通过产生磷氧自由基实现气相阻燃作用,DOPO-HQ和DiDOPO的特征基团可能在凝聚相中发挥作用。在垂直燃烧测试中三种体系均达到V-0级,其中DOPO/PLA熔滴最严重,DiDOPO/PLA体系熔滴得以抑制。此外,力学测试结果表明,DOPO/PLA拉伸强度比纯PLA下降83.1%,而DOPO-HQ/PLA和DiDOPO/PLA仅分别下降14.2%和15.6%。The thermal decomposition behaviors of three kinds of derivatives,including 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO),10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO-HQ),6H-dibenz[c,e][1,2]oxaphosphorin,6’6-(1,2-phenethyl)bis-,6’6-dioxide(DiDOPO),were studied.And effects of these DOPO derivatives on the thermal degradation behavior,flame retardancy and mechanical properties of poly(lactic acid)(PLA)were comparatively studied.TG results show that the initial decomposition temperature(T_(5%))of DOPO is 154℃,and an increased T_(5%)of DOPO-HQ of 342℃is displayed.In addition,T_(5%)of DiDOPO reaches to as high as 363℃,which is higher than that of DOPO and DOPO-HQ.As for PLA composites,T_(5%)reveals an increase trend as follow:T_(5%)(DOPO/PLA,273.5℃)<T_(5%)(DOPO-HQ/PLA,321.5℃)<T_(5%)(DiDOPO/PLA,333.8℃).T_(5%)shows an progressively increase trend with the increased thermal stability of flame retardants Furthermore,the thermal degradation kinetics results indicate that the thermal degradation activation energy of the composites material is improved.The thermal degradation of DOPO derivatives/PLA composites was investigated by thermogravimetric-infrared spectroscopy analysis(TG-IR)and pyrolysis-gas chromatography/mass spectrometry(PY-GC/MS).It shows that the three flame retardants mainly exert their gas phase flame retardant effect by generating phosphorus oxygen free radicals,and the characteristic groups of DOPO-HQ and DiDOPO may play a role in the condensation phase.All the three systems have attained the V-0 rating(UL-94),what’s more DOPO/PLA dripping is the most serious,on the contrary the dripping of DiDOPO/PLA is suppressed.Furthermore,the mechanical test results indicate that the tensile strength of DOPO/PLA decreases by 83.1%compared with pure PLA,while DOPO-HQ/PLA and DiDOPO/PLA only drops by 14.2%and 15.6%,respectively.

关 键 词：聚乳酸 DOPO衍生物 热降解 阻燃性能 力学性能 

分 类 号：TB332[一般工业技术—材料科学与工程]