A nanoscale dynamic mechanical analysis (nano-DMA) measurement method has been successfully developed for use in evaluating nanoscale dynamic viscoelastic properties in small-scale polymer materials over a range of non-ambient temperatures from -120 °C to 500 °C. Measurements have been obtained with a nanoindentation measurement system, in which two key techniques are applied. One is a thermal protection system for control and prevention of thermal drift and noise. The other is an environmental control system for preventing corrosion at high temperatures and dew condensation at low temperatures. Measurement reliability was examined by using a combination of a thermal-mechanically stable fused silica and a homogeneous sample of isotropic polyethylene terephthalate (PET). Constant hardness and modulus values of the fused silica from -120 °C to 500 °C indicated that the measurements were not affected by thermal load drift and noise even at elevated temperatures. The PET sample exhibited no significant difference in temperature dispersions of storage elastic modulus, loss elastic modulus and loss tangent between the nanoindentation measurement data and bulk data measured with a conventional DMA method. A practical application involving surface-deteriorated polyethylene (PE) tubes was used to demonstrate the validity and usefulness of this nano-DMA method. Infrared spectroscopic imaging revealed that the surface layer of the PE tubes was oxidized to form a carbonylated (O=C<) layer. The storage elastic modulus and glass-transition temperature of the surface layer were much higher than the corresponding values of the interior. These data indicate a plausible reason for why the PE tube surface deteriorates to form brittle cracks.
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机译：已成功开发了一种纳米级动态机械分析（纳米DMA）测量方法，用于评估小规模聚合物材料中的纳米级动态粘弹性，在-120℃至500℃的范围内的非环境温度范围内。用纳米凸缘测量系统获得测量，其中应用了两种关键技术。一种是用于控制和预防热漂移和噪声的热保护系统。另一个是用于防止在高温下腐蚀的环境控制系统，并在低温下露出凝结。通过使用热机械稳定的熔融二氧化硅的组合和各向同性聚对苯二甲酸乙二醇酯（PET）的均匀样品来检查测量可靠性。熔融二氧化硅的恒定硬度和模量值从-120℃-500℃表示，即使在高温下，测量也不会受到热负荷漂移和噪音的影响。宠物样品在纳米狭窄测量数据和用常规DMA方法测量的纳米狭窄测量数据和批量数据之间的储存弹性模量，损失弹性模量和损失切线没有显着差异。使用涉及表面劣化聚乙烯（PE）管的实际应用来证明该纳米DMA方法的有效性和有用性。红外光谱成像显示，将PE管的表面层氧化以形成羰基化（O = C <）层。表面层的储存弹性模量和玻璃化转变温度远高于内部的相应值。这些数据表示PE管表面劣化以形成脆性裂缝的理解原因。
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