塑料. 聚合物熔体瞬态拉伸粘度的测定

[中文适用范围]： 本文件规定了测定聚合物熔体瞬时拉伸粘度的方法的一般原理。 该程序详细介绍了在恒定应变率和恒温条件下单轴拉伸的聚合物熔体样品的测量。 该方法能够测量聚合物熔体的瞬态拉伸粘度，Hencky 应变速率通常在 0.01 s–1 至 1 s–1 范围内，Hencky 应变高达约 4，温度高达约 250 °C（参见注 1 和注 2）。 它适用于测量通常在大约 104 Pa·s 至 107 Pa·s 范围内的瞬态拉伸粘度值（参见注 3）。 注 1 注 2 使用 Hencky 应变和应变率（参见第 3 条）。 可以获得超出这些极限值的应变、应变速率和温度值。 注 3：就可测量的最低瞬态拉伸粘度值而言，仪器的操作极限是由多种因素决定的，包括样品在测试过程中保持其形状的能力和仪器的分辨率。 [外文原描述]： This document specifies the general principles of a method for determining the transient extensional viscosity of polymer melts. The procedure details the measurement of polymer melt specimens stretched uniaxially under conditions of constant strain rate and constant temperature. The method is capable of measuring the transient extensional viscosity of polymer melts at Hencky strain rates typically in the range 0,01 s –1 to 1 s –1 , at Hencky strains up to approximately 4 and at temperatures up to approximately 250 °C (see NOTEs 1 and 2). It is suitable for measuring transient extensional viscosity values typically in the range from approximately 10 4 Pa⋅s to 10 7 Pa⋅s (see NOTE 3). NOTE 1 Hencky strains and strain rates are used (see Clause 3). NOTE 2 Values of strain, strain rate and temperature outside these limiting values can be attained. NOTE 3 The operating limit of an instrument, in terms of the lowest transient extensional viscosity values that can be measured, is due to a combination of factors, including the ability of the specimen to maintain its shape during testing and the resolution of the instrument.