Low density polyethylene/clay nanocomposites Nanokompozyty polietylenu o małej gęstości z krzemianami warstwowymi

2017 ◽  
Vol 1 (3) ◽  
pp. 74-76
Author(s):  
Jolanta Janik
Keyword(s):  
Low Density Polyethylene ◽  
Clay Nanocomposites ◽  
Low Density

Microcellular foaming by using subcritical CO2 of crosslinked and non-crosslinked LDPE/clay nanocomposites

2016 ◽  
Vol 54 (2) ◽  
pp. 257-282 ◽  
Author(s):  
Ester Laguna-Gutierrez ◽  
Javier Escudero ◽  
Vipin Kumar ◽  
Miguel A Rodriguez-Perez
Keyword(s):  
Polymer Matrix ◽  
Rheological Behaviour ◽  
Batch Process ◽  
Low Density Polyethylene ◽  
Clay Nanocomposites ◽  
Low Density ◽  
Gas Solubility ◽  
Crosslinking Degree ◽  
Crosslinked Polymer ◽  
The One

The semicrystalline character of low density polyethylene adds severe difficulties to its foamability by a batch process in which the gas is dissolved into the polymer matrix under subcritical conditions. To improve the low density polyethylene foamability, two strategies have been used: the addition of nanoclays and a partial crosslinking of the polymer matrix. On the one hand, the use of nanoparticles is suggested because they act as heterogeneous nucleating sites reducing the cell size and increasing the cell density. On the other hand, crosslinking is also adopted as a solution because both the crystallinity (and hence, the gas solubility and diffusivity) and the extensional rheological properties of the polymer matrix are highly influenced by the crosslinking degree achieved. Results indicate that despite the fact that the presence of nanoclays deteriorates the rheological behaviour of the nanocomposites and, hence, the later foaming behaviour, the use of partially crosslinked polymer matrices allows achieving high expansion ratios (around 7.5) as well as enhanced cellular structures with cell sizes of approximately 15 µm.

Oxidized Wax as Compatibilizer in Linear Low-Density Polyethylene-Clay Nanocomposites: X-ray Diffraction and Dynamic Mechanical Analysis

2008 ◽  
Vol 8 (4) ◽  
pp. 1886-1894 ◽  
Author(s):  
V. G. Geethamma ◽  
Adriaan S. Luyt
Keyword(s):  
Loss Modulus ◽  
Mechanical Analysis ◽  
Low Density Polyethylene ◽  
Clay Nanocomposites ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dynamic Mechanical ◽  
Storage And Loss Moduli

Oxidized paraffin wax was used as a compatibilizer in composites of linear low-density polyethylene and layered nano silicate clays. X-ray diffraction analyses were carried out to investigate the crystalline morphology of five types of clays, oxidized wax, and their composites with LLDPE. The composites exhibited different X-ray diffraction and dynamic mechanical behaviour in the presence of different clays. Generally, the composites retained the partially crystalline behaviour of LLDPE, and no exfoliation was observed. Increased amount of wax did not change the morphology in most cases. The incorporation of clay resulted in an observable increase in the storage modulus of LLDPE. These values also increased with the addition of oxidized wax for most of the composites. The loss modulus increased with the amount of clay, irrespective of its nature. In most cases these values also increased with the incorporation of wax. The composites with 10% clay and 10% oxidized wax showed the highest storage and loss moduli, irrespective of the nature of the clay. The tan δ values did not change considerably with the addition of clay or wax.

Sign in / Sign up

Export Citation Format

Share Document