The aim of this work is the preparation of a biodegradable polymeric blend
(LDPE/AD+S) to be used for eco-friendly packaging purposes. The polymer matrix
consists mainly of low density polyethylene( LDPE), starch (S), and low quantities of
additiv
es (AD) as compatibilizers. The additives are: maleic acid, acetic acid, benzoyl
peroxide, and zinc stearate. The polymer blend LDPE/AD+S was prepared by extrusion, in
three compositions according to the percentage of starch (15,20,40%). Then, films were
prepared from the blend by thermal hydraulic compression to study their microstructure by
optical microscopic at magnification of 055 The results showed that the starch granules
were homogeneously distributed within the polymer matrix, and the compatibility
additives played an important role in enhancing the microstructure of the prepared blends.
The results also indicate that the starch promotes the onset of the bioegradation process.
A series of polymer blends are prepared by sequential mixing of epoxy resin
EP with polyurethane PU. The effect of different amount of polyurethane 10%,
20%and 30% wt fraction on conduction and dielectric relaxation has been
reported. It was found
that all blends showed three activation energies (Eac) at
all frequencies, and the glass transition temperature (Tg) was increased with
PU wt fraction. The exponent s values were estimated to be less than unity for
all blends. Cole-Cole diagram was used to evaluate the polarizability (α),
molecular relaxation time (τ) and optical dielectric constant (εOP). The
thermodynamic parameters also determined, the result showed that the Gibbs
free energy of activation (ΔG) and enthalpy (ΔH) are high for all blends.
