Abstract
The results of mechanical testing of PVA -based electrospun nanofibers and bulk in static and dynamic modes are presented. An increase in the elastic moduli resulting from sample deformation was observed in both the bulk and as-spun fibers. This increase occurs when the deformation rate exceeds a critical
value and can be attributed to the non-equilibrium dynamics of the supermolecular structures of the polymer matrix. That is, the evolution of these supermolecular structures results in an observably extended relaxation time. It is noted that the
rate of the modulus increase of the nanofibers is nearly double that of the bulk fibers’ rate. This difference can be explained by confinement influence on the polymer matrix of the nanofibers. In addition, the tests revealed that the, Tg, of the nanofiber
is noticeably higher than that of bulk specimen. Reinforcing the nanofibrs by cellulose whiskers showing that the dependence of the effective modulus on the whisker concentration has an initial increase that changes to a decrease when the whisker
concentration exceeds 2 %. Such behavior can be explained in the framework of an aggregation concept – when the cluster size reaches that of the fiber diameter (cluster confinement), the whisker distribution becomes inhomogeneous and results
in a measurable weakening of the composite.
value and can be attributed to the non-equilibrium dynamics of the supermolecular structures of the polymer matrix. That is, the evolution of these supermolecular structures results in an observably extended relaxation time. It is noted that the
rate of the modulus increase of the nanofibers is nearly double that of the bulk fibers’ rate. This difference can be explained by confinement influence on the polymer matrix of the nanofibers. In addition, the tests revealed that the, Tg, of the nanofiber
is noticeably higher than that of bulk specimen. Reinforcing the nanofibrs by cellulose whiskers showing that the dependence of the effective modulus on the whisker concentration has an initial increase that changes to a decrease when the whisker
concentration exceeds 2 %. Such behavior can be explained in the framework of an aggregation concept – when the cluster size reaches that of the fiber diameter (cluster confinement), the whisker distribution becomes inhomogeneous and results
in a measurable weakening of the composite.
| Original language | American English |
|---|---|
| State | Published - 2009 |
| Event | APS March Meeting 2009 - Pittsburgh, Pennsylvania, United States Duration: 16 Mar 2009 → 20 Mar 2009 |
Conference
| Conference | APS March Meeting 2009 |
|---|---|
| Country/Territory | United States |
| City | Pittsburgh, Pennsylvania |
| Period | 16/03/09 → 20/03/09 |