PSI - Issue 52

Hideaki Katogi et al. / Procedia Structural Integrity 52 (2024) 611–617 Hideaki Katogi / Structural Integrity Procedia 00 (2019) 000 – 000

615

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Table. 1. Result tensile properties of synthetic leathers before and after outdoor exposure tests.

Tensile strength [MPa]

Young’s modulus [ MPa]

Average value

Standard division

Average value

Standard division

Before outdoor exposure test

10.2

0.5

22.0

2.4

After outdoor exposure test

8.8

0.4

20.5

2.7

Fig. 5. Fracture morphologies of synthetic leathers (a) Before outdoor exposure test; (b) After outdoor exposure test.

synthetic leathers before and after outdoor exposure tests were almost liner. Before outdoor exposure test, the tensile strength and Young ’ s modulus of synthetic leather were about 10 MPa and about 22 MPa, respectively. Tensile strength and Young ’ s modulus of synthetic leather were decreased by outdoor exposure environment. Fig.5 shows fracture morphologies of synthetic leathers before and after outdoor exposure tests. Fracture morphologies of synthetic leathers became flat before and after outdoor exposure tests. The synthetic leather consists of non-woven fabric using polyester. But, the long fiber pull-out in fracture morphology of synthetic leather also did not occur after outdoor exposure test. Generally, water absorptions of polyester and polyurethane almost do not occur during outdoor exposure environment because water absorption rates of polyester and polyurethane are small [26, 27]. So, tensile properties of polyester and polyurethane were not probably affected by water absorption under outdoor exposure environment. But, the tensile property of polyurethane as constituent material of synthetic leather is affected by ultraviolet irradiation [9, 28]. In this study, tensile property of polyester at back side of synthetic leather is not probably