ma5b02585_si_001.pdf (1.14 MB)
Elasticity Reinforcement in Propylene–Ethylene Random Copolymer Stretched at Elevated Temperature in Large Deformation Regime
journal contribution
posted on 2016-01-26, 00:00 authored by Jiayi Zhao, Yingying Sun, Yongfeng MenTensile deformation behavior of a
random propylene–ethylene
copolymer with 12 mol % ethylene counits at room temperature and 63
°C was investigated using the in situ small and wide-angle X-ray
scattering techniques. Under both conditions, the deformation mechanism
changed from slip of crystalline lamellar blocks to stretching induced
melting and recrystallization process at a critical strain of about
0.9. This critical strain in tensile deformation of semicrystalline
polymers normally marks the starting of plateau value of elastic strain.
Further stretching leads to increase of plastic deformation only due
to the fibrillation. However, a peculiar elasticity reinforcement
was observed at strain larger than 1.3 when the sample was stretched
at 63 °C. Wide angle X-ray scattering results indicate that at
this strain of 1.3 fibrillation of the originally unoriented crystals
finished so that further stretching leads to a deformation of a rather
stable entangled network embedded by fibrils that possesses high elasticity.