Oxygen permeability, electron spin resonance, differential scanning calorimetry and positron annihilation lifetime spectroscopy studies of uniaxially deformed linear low-density polyethylene film

2012 ◽  
Vol 62 (3) ◽  
pp. 474-481 ◽  
Author(s):  
Damir Klepac ◽  
Mario Ščetar ◽  
Mia Kurek ◽  
Peter E. Mallon ◽  
Adriaan S. Luyt ◽  
...  
2018 ◽  
Vol 35 (2) ◽  
pp. 75-89 ◽  
Author(s):  
Maciej Kisiel ◽  
Beata Mossety-Leszczak ◽  
Agnieszka Frańczak ◽  
Dominik Szczęch

A method of quantitative analysis of polypropylene/linear low density polyethylene blends was determined by using differential scanning calorimetry. The samples were prepared by means of extrusion process. The method of quantitative analysis was based on the principle that the melting enthalpies of the components in the mixture are proportional to their amount, but it has been found that the presence of two polymers in the blend has influence on the crystallization of its components. Previous studies seemed to neglect this phenomenon, so a linear correlation allowing to eliminate discrepancies between calculated and actual quantitative blend composition has been developed. This approach was proven to be more accurate than earlier directly proportional enthalpy—quantity dependence.


2010 ◽  
Vol 63 (8) ◽  
pp. 1201 ◽  
Author(s):  
Shingo Kobayashi ◽  
Christopher W. Macosko ◽  
Marc A. Hillmyer

Model hexyl-branched linear low density polyethylene (C8-LLDPE) samples were synthesized by the ring-opening metathesis copolymerization (ROMP) of the 5-hexylcyclooct-1-ene (1) and cyclooctadiene (COD), followed by catalytic hydrogenation. The ROMP of 1 and copolymerization of 1 and COD using the Grubbs second generation catalyst (G2) afford polymers with the number of hexyl branches based on the feed composition. The resulting hexyl-branched polymers, poly(1) and poly(1-stat-COD), were completely converted into model C8-LLDPE samples by catalytic hydrogenation. The C8-LLDPE samples exhibit the expected reduction in density on branching content. The melting temperature (Tm), crystallization temperature (Tc), and heat of fusion/crystallization (ΔHm/ΔHc) of these materials were studied by differential scanning calorimetry.


2015 ◽  
Vol 815 ◽  
pp. 14-18
Author(s):  
P. Santhiya ◽  
S.T. Sam ◽  
H. Kamarudin ◽  
S. Ragunathan ◽  
N.Z. Noriman ◽  
...  

The properties of blends made from low density polyethylene (LDPE) with various concentration of jackfruit seeds flour (JSF) with the presence of citric acid (CA) were investigated. The JSF content was varied from 0 to 20 wt%. The JSF were blended with LDPE by using an internal mixer (Brabender) at a temperature of 150°C. The test was carried out by using differential scanning calorimetry (DSC), with heating temperature of 100C/min. The crystallinity had improved with the presence of CA. However, the crystallinity slightly reduced with the increasing JSF content and further increased with the presence of CA.


2013 ◽  
Vol 33 (7) ◽  
pp. 579-588 ◽  
Author(s):  
S.T. Sam ◽  
H. Ismail ◽  
H.P.S. Abdul Khalil

Abstract In the present study, linear low density polyethylene (LLDPE)/soya powder blends were compatibilized with epoxidized natural rubber (ENR 50) and exposed to natural weathering. The exposure period for the blends was 1 year. It was found that the degradability of the compatibilized blends was higher than that of uncompatibilized blends. Fourier transform infrared (FTIR) spectra, the tensile test, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) were applied to analyze the degradability of the blends. IR spectra showed that the carbonyl index (CI) of the blends increased as a function of exposure period and soya powder content. The compatibilized blends gave higher carbonyl indices. The retention tensile strength and elongation at break (Eb) of the compatibilized blends after weathering was generally lower than for the uncompatibilized blends. The increase of crystallinity also indicated a reduction of the amorphous portion after degradation. The higher crystallinity in compatibilized blends further confirms the higher degradability of ENR 50 compatibilized blends. The weight loss and molecular weight change indicated that the incorporation of ENR 50 into LLDPE/soya powder blends can enhance the degradability of the blends upon outdoor exposure.


2013 ◽  
Vol 795 ◽  
pp. 433-437 ◽  
Author(s):  
S.T. Sam ◽  
N.Z. Noriman ◽  
S. Ragunathan ◽  
O.H. Lin ◽  
H. Ismail

Soya spent powder as an inexpensive and renewable source has been used as a filler for linear-low density polyethylene (LLDPE) in this study. Linear-low density polyethylene (LLDPE)/soya spent powder composites were prepared by using Haake internal mixer. The mixing time was 10 minutes at 150°C with rotor speed 50 rpm. Epoxidised natural rubber (ENR 50) has been used as a compatibilizer in the present study. The thermal properties of the LLDPE/soya spent powder composites with and without ENR were studied with a differential scanning calorimetry (DSC). The crystallinity of the LLDPE/soya spent powder composites decreased with increasing soya spent powder content. However, the addition of ENR 50 as a compatibilizer increased the crystallinity of the LLDPE/soya spent powder composites.


Sign in / Sign up

Export Citation Format

Share Document