塑料 - 动态机械性能的测定 - 第11部分:玻璃化转变温度

[中文适用范围]： 本文件规定了根据加热条件下线性温度扫描期间测量的动态机械性能确定玻璃化转变温度 (Tg) 值的方法。 玻璃化转变温度是无定形聚合物或部分结晶聚合物的无定形区域中从硬且相对脆的玻璃态向橡胶态或粘性液态转变的指标。 通常称为动态机械分析 (DMA)，该方法及其相关程序可应用于非增强和填充聚合物、泡沫、橡胶、粘合剂和纤维增强塑料/复合材料。 该方法仅限于在Tg以上本质上稳定的材料，即转变成橡胶态的无定形材料或由于结晶度而保持其形状的部分结晶材料。 动态机械分析的不同模式（例如弯曲、扭转、剪切、压缩、拉伸）可以酌情应用于源材料的形式。 使用仪器测量的 Tg 值可能因材料特性和/或测试设置而异。 DMA 仪器中的温度传感器不与测试样本接触，因此测量测试样本周围环境的温度。 所得数据可能随所应用的加热速率而变化。 其中包括一个程序来考虑影响测量数据的热滞后。 [外文原描述]： This document specifies methods for determining a value of the glass transition temperature ( T g) from the dynamic mechanical properties measured during a linear temperature scan under heating conditions. The glass transition temperature is an indicator of the transition from a hard and relatively brittle glassy state to a rubbery or viscous liquid state in an amorphous polymer or in amorphous regions of a partially crystalline polymer. Usually referred to as dynamic mechanical analysis (DMA), the methods and their associated procedures can be applied to unreinforced and filled polymers, foams, rubbers, adhesives and fibre-reinforced plastics/composites. The methods are limited to materials that are inherently stable above T g , i.e. amorphous materials that transform into a rubbery state or partially crystalline materials that keep their shape due to crystallinity. Different modes (e.g. flexure, torsion, shear, compression, tension) of dynamic mechanical analysis can be applied, as appropriate, to the form of the source material. Measured T g values using instrumentation can vary as a result of material characteristics and/or the test set-up. The temperature sensor in a DMA instrument is not in contact with the test specimen and therefore measures temperature of the environment surrounding the specimen under test. The resulting data can vary with the heating rate applied. A procedure is included to take into account the thermal lag influencing the measured data.