The optical, mechanical, and photoelastic anisotropy of biaxially stretched polyethylene terephthalate (PET) films are addressed. Transmission ellipsometers and analysis software were used to determine the optical axis and in‐plane and out‐of‐plane birefringences of the PET films. The principal axis of stress coincides with the optical axis, but they...

The stretching‐induced II‐I phase transition was studied with the combination of in situ wide‐angle X‐ray diffraction and mechanical testing. Three orientation pathways were distinguished for the phase transition in the butene‐1/ethylene random copolymer, which is determined by stretching speed and temperature. Interestingly, a master stress‐determined...

The reversing and nonreversing variations of amorphous poly(l‐lactide) conformer relative concentration as a function of temperature are investigated by modulated temperature Fourier transform infrared. It is observed that different thermal histories of the polymer above the glass transition temperature affect the relaxation of the glass during the...

The nonlinear viscoelastic response to large amplitude oscillatory shear of mixtures of entangled polymer chains—both unattached and attached to nanoparticle surfaces has been modeled using a double reptation formulation of the Marrucci–Ianniruberto tube model. The mixture model developed here also incorporates different convective constraint release...

A 3D numerical model using the finite element method is built in order to predict gas barrier properties in nanocomposite systems where fillers, considered as disks, are distributed regularly and uniformly in a unit cell. The specificity of the model is its validity for a wide range of fillers volume fractions and aspect ratios. A phenomenological analytical...

Recent advances in smart materials and manufacturing have the potential to enable fabrication of active structures and complex systems. Lately, the number of smart materials manufactured by 3D printing has drastically increased by a large extent, leading to high performance of 4D objects. This paper demonstrates that the combination of a piezoelectric...