Characterization of Thermo-Mechanical and Fracture Behaviors of Thermoplastic Polymers

Abstract

In this paper the effects of the strain rate on the inelastic behavior and the self-heating under load conditions are presented for polymeric materials, such as polymethyl methacrylate (PMMA), polycarbonate (PC), and polyamide (PA66). By a torsion test, it was established that the shear yield stress behavior of PMMA, PC, and PA66 is well-described by the Ree-Eyring theory in the range of the considered strain rates. During the investigation, the surface temperature was monitored using an infrared camera. The heat release appeared at the early stage of the deformation and increased with the strain and strain rate. This suggested that the external work of deformation was dissipated into heat so the torsion tests could not be considered isothermal. Eventually, the effect of the strain rate on the failure modes was analyzed by scanning electron microscopy.

Ductility and Flame Retardancy Enhancement of PVC by Nanostructured Fly Ash

“…3c-d). The agglomeration, formation of voids and vacancies at pullout of the filler particles have resulted in transformation of PVC composites behavior from semi-ductile to brittle fracture [21] as shown in Scheme 2. This trend is presumably the consequence of high stiffness of the fresh FA as filler, which alters the ductility of the PVC matrix.…”

Comparatively Thermal and Crystalline Study of Poly(methyl‐methacrylate)/Polyacrylonitrile Hybrids: Core–Shell Hollow Fibers, Porous Fibers, and Thin Films

“…The spectra of the PMMA powders, PMMA fibers, PMMA/PAN porous thin films, core–shell hollow PMMA/PAN fibers, and PMMA/PAN porous fibers showed the obvious peaks at around 2950 and 3002 cm −1 , attributing to the CH bonds stretching vibrations of the CH 2  and CH 3 groups in PMMA (Figure c–e) . And the peak at 1450 cm −1 , at the same position with PAN, was assigned to the CH vibration of PMMA . The peak at 2362 cm −1 (OCH 3 stretch) was observed in the PMMA powders, but disappeared in the PMMA fibers (Figure b), which may be caused by the severe synthesis condition (high voltage, 15.0 kV), similar to the synthesis procedure of the silica aerogels .…”

“…When the PAN was processed into fibers (Figure f), the peak at 2340 cm −1 (CN conjugation) displayed stronger intensity, probably due to the cyclization reaction between DMF and PAN . And the stretching nitrile (CN) group shifted to higher energy position at 2360 cm −1 (CN), ascribing to the interaction of amide nitrogen (DMF) and nitrile group (PAN) . The spectra of raw PMMA powder, PMMA fibers, PMMA/PAN porous thin films, core–shell hollow PMMA/PAN fibers, and PMMA/PAN porous fibers showed a weak peak around 999 cm −1 and two strong peaks at 1146 and 1726 cm −1 , corresponding to the vibrations of C–H, axial asymmetric bend of CCO and PMMA ester (CO) groups, respectively (Figure a–e) .…”

Manipulating selective dispersion of reduced graphene oxide in polycarbonate/nylon 66 based blend nanocomposites for improved thermo-mechanical properties

“…Pure nylon 66 and polycarbonate shows their characteristic IR peaks, including stretching and weak wagging, rocking and bending vibrations. 41,42 To examine interaction between nylon 66 and PC, the N-H stretching frequency of nylon (around 3400 cm À1 ) has been analyzed, because of a probable interaction between nylon 66 and polycarbonate through (-O/N-H) hydrogen bonding.…”