Comparative study on development of structural hierarchy in constrained annealed simultaneous and sequential biaxially stretched polylactic acid films

Effect of the simultaneous biaxial stretching on the structural and mechanical properties of PLA, PBAT and their blends at rubbery state

“…It should be noted that a mesophase (formed by the orientation and periodic organization of amorphous chains) can exist in the earlier stages of crystallization, acting as precursor and disappearing to form an imperfect crystal which develops by becoming more and more ordered [24]. Indeed, a similar mechanical behavior was observed in PET stretched above the glass transition temperature [13,25,26].…”

“…The crystallinity development through the strain-induced crystallization (SIC) represents an important approach for manufacturing biodegradable PLA films with good properties for several practical applications such as blowing injection and thermoforming [6,12,13]. Crystal structure can be formed in the amorphous PLA films in uniaxial and biaxial stretching [10,11].…”

“…In fact, the biaxial oriented PLA film with high crystallinity ensures dimensional stability at temperatures above 100°C. The structural evolution during simultaneous and sequential rubbery state biaxial stretching has also been studied [13]. Compared to uniaxial stretching (which leads to gradual development of orientation particularly beyond the strain hardening and consequent oriented crystallization with well established three-dimensional order), simultaneous biaxial stretching always leads to films with in-plane isotropy and poor crystalline order.…”

Influence of Boehmite Nanoparticle Loading on the Mechanical, Thermal, and Rheological Properties of Biodegradable Polylactide/Poly(ϵ‐caprolactone) Blends

“…The results of the melt rheology for selected samples are summarized in Figure . The dynamic storage modulus is considered to be one of the rheological properties that can provide the most accurate information regarding the phase inversion of polymer blends …”

Evaluation of a Bioabsorbable Self-Expandable Vein Stent-Base Made of Poly(l-lactide) In Vitro and In Vivo

“…Stent bases made from bioabsorbable polymers have inferior mechanical properties to those of metals and both radial force and resistance to a permanent deformation is low. PLLA can be induced with a greater stiffness, and provide greater resistance toward permanent deformation by straining the polymer above its glass transition temperature and thereby align its molecular chains [ 18,19,20 ]. The scope of this study was to evaluate the performance of a self expandable PLLA vein stent base in vitro and in vivo.…”