Journal of Polymer Science Part B Polymer Physics · 2002 · 143 citations · 10 references
EngineeringMechanical EngineeringTensile MechanicsChemistrySoft MatterStrain RateMechanics ModelingAbstract Tensile TestsStrength PropertyMethyl MethacrylateStressstrain AnalysisRheologyPolymer ChemistryMaterials ScienceMechanical BehaviorTensile TestsMaterial MechanicsPolymer AnalysisMechanical PropertiesPolymer SciencePolymer CharacterizationPolymer PropertyMechanics Of Materials
The study aimed to clarify how humidity and strain rate affect the tensile properties of poly(methyl methacrylate), especially its Young’s modulus. Specimens were conditioned at various humidity levels at 293 K, then tensile tests were performed at three strain rates (≈1.4 × 10⁻³, 1.4 × 10⁻⁴, 1.4 × 10⁻⁵ s⁻¹) while measuring Young’s modulus at low stresses, and a constitutive equation was derived. Stress–strain curves varied with humidity and strain rate, and Young’s modulus decreased linearly with increasing humidity and with the logarithm of strain rate, allowing it to be expressed as a function of these two parameters. © 2002 Wiley Periodicals, Inc., J Polym Sci Part B: Polym Phys 40: 460–465, DOI 10.1002/polb.10107.
Abstract Tensile tests on poly (methyl methacrylate) (PMMA) were conducted to clarify the effects of humidity and strain rate on tensile properties, particularly Young's modulus. Prior to the tensile tests, specimens were kept under various humidity conditions at 293 K, which were the same as the test conditions, for a few months to adjust the sorbed water content in the specimens. The tensile tests were performed under each humidity condition at three different strain rates (approximately 1.4 × 10 −3 , 1.4 × 10 −4 , and 1.4 × 10 −5 s −1 ). Stress‐strain curves changed with humidity and strain rate. Young's moduli were also measured at small applied stresses (below 6.7 MPa) under various humidity conditions at 293 K. Young's modulus decreases linearly with increasing humidity and a decreasing logarithm of strain rate. These results suggest that Young's modulus of PMMA can be expressed as a function of two independent parameters that are humidity and strain rate. A constitutive equation for Young's modulus of PMMA was proposed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 460–465, 2002; DOI 10.1002/polb.10107
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