Influence of temperature on low-density polyethylene films through conduction measurement

2002 ◽  
Vol 35 (13) ◽  
pp. 1555-1561 ◽  
Author(s):  
L Boudou ◽  
J Guastavino
Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 587 ◽  
Author(s):  
Guochang Li ◽  
Jiaxing Wang ◽  
Wang Han ◽  
Yanhui Wei ◽  
Shengtao Li

Temperature is one of the key factors affecting space charge accumulation in high voltage direct current (HVDC) cable insulation material. The influence of temperature on charge accumulation in low density polyethylene (LDPE) has been investigated with a combined thermally stimulated depolarization current (TSDC) method and pulsed electro-acoustic (PEA) method. The experimental results indicate that there exists a transition temperature region of charge accumulation around 50 °C. The total accumulated charges all firstly increase and then decrease with the increasing polarization temperature under three typical polarization electric fields, and they have more accumulated charges in LDPE around 50 °C. The phenomenon has a close link with the dynamic processes of charge trapping and de-trapping, which were verified by TSDC results. At room temperature, the trapped charges are difficult to release from the traps, and these homocharges near the cathode can depress the further injection of the charges. More charges can be injected from the electrodes with the increase of temperature, while the charge migration is relatively lower before 50 °C, leading to more accumulated charges. When the temperature exceeds around 50 °C, the molecular movement is accelerated which can enhance the hopping probability of charges between the adjacent traps, resulting in few accumulated charges.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Razieh Niazmand ◽  
Bibi Marzieh Razavizadeh ◽  
Farzaneh Sabbagh

The physical, thermal, mechanical, optical, microstructural, and barrier properties of low-density polyethylene films (LDPE) containing ferula asafoetida leaf and gum extracts were investigated. Results showed a reduction in elasticity and tensile strength with increasing extract concentration in the polymer matrix. The melting temperature and enthalpy increased with increasing concentration of extracts. The films containing extracts had lower L∗ and a∗ and higher b∗ indices. The films containing leaf extract had more barrier potential to UV than the gum extracts. The oxygen permeability in films containing 5% of leaf and gum extracts increased by 2.3 and 2.1 times, respectively. The morphology of the active films was similar to bubble swollen islands, which was more pronounced at higher concentrations of gum and leaf extracts. FTIR results confirmed some chemical interactions of ferula extracts with the polymer matrix. At the end of day 14th, the growth rate of Aspergillus niger and Saccharomyces cerevisea in the presence of the PE-Gum-5 reduced more than PE-Leaf-5 (3.7 and 2.4 logarithmic cycles, respectively) compared to the first day. Our findings showed that active LDPE films have desire thermo-mechanical and barrier properties for food packaging.


2021 ◽  
pp. 50559
Author(s):  
Pamela Rodrigues Passos Severino ◽  
Natália Ferreira Braga ◽  
Guilherme Ferreira Morgado ◽  
Juliano Marini ◽  
Orestes Ferro ◽  
...  

2003 ◽  
Vol 90 (11) ◽  
pp. 2938-2944 ◽  
Author(s):  
Siddaramaiah ◽  
T. Jeevananda ◽  
K. S. Jagadeesh ◽  
H. Somashekarappa ◽  
R. Somashekar

2017 ◽  
Vol 890 ◽  
pp. 82-85 ◽  
Author(s):  
Reymark D. Maalihan ◽  
Bryan B. Pajarito

This work reports the effect of temperature on degradation of colored low-density polyethylene (PE) films during thermal aging. Film samples were formulated according to Taguchi design of experiments where colorant, thickness, and pro-oxidant concentration were varied accordingly. Tensile properties of films were monitored with time during heat aging in a hot air oven at 50, 70, and 90 °C. Likewise, surfaces of aged films were analyzed to evaluate the degree of oxidation of PE during thermal aging. The Arrhenius equation was then used to predict the lifetime of PE at an in-use temperature of 30 °C. Results indicate that increasing the temperature reduces the tensile strength and modulus of films. Formation of carbonyl groups as degradation products is also observed at higher temperatures. Consequently, thermal aging at 90 °C offers the highest extent of degradation of exposed films. Regression analysis reveals that white films degrade at a higher rate than yellow and non-colored films. The presence of TiO2 in white films shortens the lifetime of PE while amine stabilizer in yellow films enhances the stability of PE during thermal aging.


2001 ◽  
Vol 40 (Part 1, No. 1) ◽  
pp. 206-212 ◽  
Author(s):  
Don-Chan Cho ◽  
Tatsuo Mori ◽  
Teruyoshi Mizutani ◽  
Mitsugu Ishioka

Author(s):  
S. JIPA ◽  
R. SETNESCU ◽  
T. SETNESCU ◽  
C. PODINA ◽  
J. MIHALCEA

The effectiveness of different phenolic antioxidants on high-density polyethylene (HDPE) and low-density polyethylene (LDPE) has been studied by the Isothermal chemiluminescence method. The decreasing order of the antioxidant efficiency for these polymers Is as follows: lrganox 1010 >> Etanox 330 > lrganox 1076 (Hostanox 016) > Topanol OC


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