Effects of clay dispersion on the foam morphology of LDPE/clay nanocomposites

Abstract

Intercalated and exfoliated low-density polyethylene (LDPE)/clay nanocomposites were prepared by melt blending with and without a maleated polyethylene (PE-g-MAn) as the coupling agent. Their morphology was examined and confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The effects of clay content and dispersion on the cell morphology of nanocomposite foams during extrusion foaming process were also thoroughly investigated, especially with a small amount of clay of 0.05-1.0 wt%. This research shows the optimum clay content for achieving microcellular PE/clay nanocomposite foams blown with supercritical CO 2 . It is found that < 0.1 wt% of clay addition can produce the microcellular foam structure with a cell density of > 10 9 cells/cm 3 and a cell size of $ 5 mm.

Low density polyethylene/silica nanocomposite foams. Relationship between chemical composition, particle dispersion, cellular structure and physical properties

“…The effect of adding a compatibilizer agent has also been carefully analyzed. Lee et al [16] and Seraji and co-workers [17] performed similar studies using low density polyethylene (LDPE) as polymeric matrix and montmorillonite (MMT) as filler. They concluded that the addition of a compatibilizer led to a clay exfoliation and only in this case, the nucleation effect induced by MMT was effective.…”

Assisted heterogeneous multinucleation and bubble growth in semicrystalline ethylene-vinyl acetate copolymer/expanded graphite nanocomposite foams: Control of morphology and viscoelastic properties

“…To seek this aim, different continuous and discontinuous process variants have been developed to prepare microcellular foam morphologies from glassy polymers [1,3,4]. Similarly, there are some reports about clay reinforced nanocomposite foams based on semicrystalline polymers [5][6][7][8]. Moreover, microcellular foaming process is one of the techniques that have been studied for this purpose [9][10][11][12][13][14][15][16].…”

Microcellular foaming of PP/EPDM/organoclay nanocomposites: the effect of the distribution of nanoclay on foam morphology

“…12 It is well known that cell density and cell size are the most important characteristics of microcellular foams, and the majority of the studies of microcellular foams have been focused on increasing cell density and decreasing cell size. [15][16][17] More recently, the incorporation of nanoscaled additives has been considered to enhance cell nucleation and produce more bubbles with a finer morphology. [16][17][18][19][20][21] Nanocellular foams have also been achieved in some cases.…”

“…[15][16][17] More recently, the incorporation of nanoscaled additives has been considered to enhance cell nucleation and produce more bubbles with a finer morphology. [16][17][18][19][20][21] Nanocellular foams have also been achieved in some cases. 22,23 Furthermore, the addition of nanofillers to polymers cause remarkable improvement in their properties, such as the modulus, strength, thermal stability and gas permeability resistance, compared with non-filled and microfilled ones.…”