ISO 23508:2021 pdf download – Solution-polymerized SBR — Evaluation methods of viscoelastic properties.
7 Evaluation of vulcanization characteristics 7.1? General Evaluation of vulcanization characteristics is carried out according to either 7.2 or 7.3. 7.2? ?Evaluation? according? to? oscillating? disc? curemeter? test Measure the following standard test parameters: M L , M H , t c ′ (10), t c ′ (50) and t c ′ (90) in accordance with ISO 6502-2, using the following test conditions: — oscillation frequency: 1,7 Hz (100 cycles per minute); — amplitude of oscillation: ±1° arc; — selectivity: to be chosen to give at least 75 % full scale deflection at M H ; — die temperature: 160,0 °C ± 0,3 °C; — pre-heat time: none. 7.3? ?Evaluation? according? to? rotorless? curemeter? test Measure the following standard test parameters: M L , M H , t c ′ (10), t c ′ (50) and t c ′ (90) in accordance with ISO 6502-3, using the following test conditions: — oscillation frequency: 1,7 Hz (100 cycles per minute); — amplitude of oscillation: 0,5° arc; — selectivity: to be chosen to give at least 75 % full scale deflection at M H ; — die temperature: 160,0 °C ± 0,3 °C; — pre-heat time: none.
8 Evaluation of dynamic viscoelastic properties 8.1? General Regarding the dynamic viscoelastic properties, two kinds of evaluations, the strain dependency (see 8.4) and the temperature dependency (see 8.5), shall be carried out. In the strain dependency, it is possible to evaluate the change in the filler network structure, that is, the dispersibility of the filler in a compound. In temperature dependency, temperature dependency of complex modulus, including glass transition temperature and mobility of molecular chain can be evaluated. The strain dependency of the filling compound is known as the Payne effect [8][9] (see Annex D) and reflects the filler networks. The difference in absolute value of complex modulus between low strain and high strain is conventionally used as an indicator of the filler dispersibility. Especially, it is known that when the polymer type is changed to the functionalized polymer, the difference value greatly decreases. It is useful as an indicator of filler dispersibility by polymer types. See Figure C.1.
The temperature dependency is useful for expressing the properties of polymers at each service temperature of application products. Peak temperature of tan δ curve is useful for detecting the glass transition temperature. See Figure C.2. The reliability of the obtained data may be confirmed by reference to Annex B. Examples of viscoelastic measurement are given in Annex C. 8.2? Sample? preparation Test pieces may be moulded or cut from vulcanized sheet. Moulding is preferred for shear and compression test pieces. Metal plates for shear and compression test pieces may be bonded during moulding or bonded afterwards with a thin layer of suitable adhesive. Vulcanization time is determined from the results of 7.2 or 7.3 to prepare a vulcanized sheet. The test piece shall not be deformed before measurement. In addition, test pieces used once shall not be used again.