湿度对高分子氢键复合物纤维力学行为的影响

Effect of Humidity on Mechanical Behavior of Polymer Hydrogen-bonding Complex Fibers

高分子复合物具有刺激响应特性,随环境变化表现出结构或性能转变.以聚丙烯酸(PAA)作为氢键给体,分别以聚乙烯吡咯烷酮(PVPON)、聚2-乙基-2-唑啉(PEOX)和聚环氧乙烷(PEO)作为受体,制备了3种氢键复合物纤维. 3种纤维的力学性能都随湿度变化而变化,且对湿度的依赖性与高分子氢键复合强度相关.通过动态力学测试,利用时间-湿度叠加方法构建了高分子氢键复合物纤维的模量-频率主曲线,呈现了较宽时间范围内的力学松弛现象.为湿度响应的高分子复合物材料的开发及应用提供指导与支持.

Polymer complexes exhibit environmental-responsiveness owing to the integration and assembly of stimuli-sensitive components,leading to the changes in their structure or properties.Humidity is one of the general environmental parameters which can influence the fabrication and application of polymer complexes,and thus it is important to investigate the effect of humidity on the structure and properties of polymer complexes.Herein,three hydrogen-bonding complex fibers were constructed using poly(acrylic acid)(PAA)as a hydrogen-bonding donor,and polyvinylpyrrolidone(PVPON),poly(2-ethyl-2-oxazoline)(PEOX)and poly(ethylene oxide)(PEO)as the hydrogen-bonding acceptors.Results show that the strength of hydrogen-bonding complexation affects the morphology and glass-transition temperature of the prepared complex fibers.With the increase in humidity,PAA/PVPON fiber stayed in a glassy state while PAA/PEOX fiber presented a glass-transition-like behavior at high humidity.As for PAA/PEO fiber,it showed a rubber-like transition behavior even at low humidity.It is found that the mechanical properties of the complex fibers are different mainly attributed to the different complexation strengthes,chain structures and water contents in the systems.The storage modulus-frequency master curve of polymer complex under humidity field was constructed using time-humidity superposition technique through dynamic mechanical multi-frequency strain test,and the mechanical relaxation in a wide time range was presented.Above all,this work can provide basic guidance for constructing humidity-response materials and analyzing the service capability of polymer complex materials.