|
Abstract
|
Ethylene-vinyl alcohol copolymers (EVOH), with
appropriate barriers and processability, can be chemically
modified through vinyl alcohol units. Amides and polyamides
based on condensation reactions of adipoyl chloride
and hexamethylenediamine were grafted onto EVOH.
Grafting was characterized by contact angle measurement,
attenuated total reflection Fourier transform infrared
spectroscopy (ATR-FTIR), nuclear magnetic resonance
spectroscopy (NMR) and scanning electron microscopy
(SEM). Amide peaks at 3302 cm-1 corresponding to –NH
bond stretching and the absorption of HN-CH2 at 7.8 ppm,
were observed from ATR-FTIR and NMR, respectively, as
a result of grafting. SEM showed the formation of amide
structures as bundles, agglomerates and needle-like particles.
Differential scanning calorimetry (DSC) and dynamic
mechanical thermal analysis (DMTA) showed considerable
changes in onset of melt temperature, crystallinity and
various transitions in grafted EVOH, showing an effective
alteration in the physical properties compared with the
virgin resin. Nylon grafted EVOH can be considered as a
potential compatibilizer in polyethylene (PE)/polyamide blends via increasing interactions at the interface.
|