2,779 research outputs found
Post-yield deformation of an epoxy resin and of an epoxy/layered silicate nanocomposite as investigated by strain recovery experiments
No full textStrain recovery kinetics of epoxy resins deformed above yielding: effect of the cross-link density
No full textStrain Recovery Behavior Of Post-Yield Deformed Epoxy Resins: Effect Of The Resin/Hardener Ratio
No full textThe effect of the resin/hardener ratio on the strain recovery kinetics of various post-yield deformed epoxy resins is investigated in isothermal tests and in thermally stimulated recovery tests. Recovery is seen to take place following a two-stage process, in which the different stages can be distinguished on the time and temperature scales. These two recovery contributions are differently affected by the resin/hardener ratio and by the applied deformation
Strain recovery and stored energy release of a post-yield deformed epoxy resin and its epoxy/layered silicate nanocomposite
No full textThe strain recovery behaviour of an epoxy resin and of an epoxy-layered silicate nanocomposite deformed at high nominal strain levels (50%) was investigated in isothermal recovery experiments. By representing the whole recovery process in terms of strain recovery master curves, it was possible to evidence differences in the recovery features of the two materials. Further, the study of the energy stored in the materials and of its release process permitted to distinguish the part of recovery occurring with heat release from that occurring after that all the stored energy is released
Effect of the matrix composition on the strain recovery kinetics of epoxy resins deformed above yielding
No full textEpoxy / clay nanocomposites: effect of the resin molecular weight and clay modification on the mechanical properties
No full textExperimental investigation on the strain recovery behavior of post-yield deformed epoxy resins
No full textEffect of the Resin/Hardener Ratio on Yield, Post-yield,and Fracture Behavior of Nanofilled Epoxies
No full textIn this work, the effect of the resin/hardener ratio on the small deformation, yield, post-yield, and fracture behavior of a series of DGEBA-Jeffamine epoxy-clay nanocomposites with a fixed organo-clay content (6 phr), and of the corresponding unfilled resins, was investigated. The mechanical behavior at small deformation was studied by means of uniaxial tensile tests, whereas compression tests were employed to investigate the large (yield and post-yield) deformation levels. The fracture behavior was studied by the application of fracture mechanics testing methods. The results pointed out that small variations in the resin/hardener ratio used for the preparation of the resin can give rise to remarkable differences in the mechanical behavior at large deformation levels and at fracture. These effects were related to the parameters characteristic of the macromolecular architecture of the resins (chain segments flexibility and crosslink density). The results obtained on nanofilled systems showed that the effect of the resin/hardener ratio on the mechanical behavior of the resins is reduced in presence of organoclay particles
Superabsorbent Biphasic System Based on Poly(Lactic Acid) and Poly(Acrylic Acid)
No full textIn this research work, biocomposites based on crosslinked particles of poly(acrylic acid), commonly used as
superabsorbent polymer (SAP), and poly-L-lactic acid (PLLA) were developed to elucidate the role of the filler (i.e.,
polymeric crosslinked particles) on the overall physico-mechanical behavior and to obtain superabsorbent thermoplastic
products. Samples prepared by melt-blending of components in different ratios showed a biphasic system with a regular
distribution of particles, with diameter ranging from 5 to 10 m, within the PLLA polymeric matrix. The polymeric
biphasic system, coded PLASA i.e. superabsorbent poly(lactic acid), showed excellent swelling properties, demonstrating
that cross-linked particles retain their superabsorbent ability, as in their free counterparts, even if distributed in a
thermoplastic polymeric matrix. The thermal characteristics of the biocomposites evidence enhanced thermal stability in
comparison with neat PLLA and also mechanical properties are markedly modified by addition of crosslinked particles
which induce regular stiffening effect. Furthermore, in aqueous environments the particles swell and are leached from
PLLA matrix generating very high porosity. These new open-pore PLLA foams, produced in absence of organic solvents
and chemical foaming agents, with good physico-mechanical properties appear very promising for several applications,
for instance in tissue engineering for scaffold production
- …
