标准编号：ISO 6721-11:2019
中文名称：塑料 动态机械性能的测定 第11部分：玻璃化温度
英文名称：Plastics — Determination of dynamic mechanical properties — Part 11: Glass transition temperature
发布日期：2019-06
标准范围
This document specifies methods for determining a value of the glass transition temperature (Tg )
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
Tg , 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 Tg 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.
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