Relationship between Tensile Modulus and Oxygen Uptake of Pro-Oxidant Loaded Low-Density Polyethylene Films during Heat Aging

Article Preview

Abstract:

Polyethylene (PE) films with pro-oxidants are commonly used in agricultural and packaging industries due to their inherent biodegradability when initially expose to heat and/or light in the presence of oxygen. The degradation of films is characterized by formation of oxidation products, weight changes and loss of mechanical properties. This study investigated the relationship between tensile modulus and oxygen uptake of low-density PE films with pro-oxidants under thermal treatment at 50 and 70 °C. Blown-type films of varying colorants, thickness and pro-oxidant loading were formulated according to Taguchi design of experiments. Tensile modulus and oxygen uptake of thermally aged films were obtained from force-stroke curves and gravimetric tests, respectively. Results revealed that two out of nine formulated films showed tensile modulus to be significantly increasing with oxygen uptake at 50 °C. Correlation was more evident at 70 °C where seven out of nine formulations followed the same trend. The improvement in tensile modulus with oxygen uptake indicates increase in crystallinity of films during thermal aging. Increase in hydroxyl index of films with exposure time confirmed their degradation during heat aging. Consequently, concentration of carboxylic acids as major thermo-oxidation products was found higher at 70 °C of aging.

You might also be interested in these eBooks

Info:

Periodical:

Pages:

72-76

Citation:

Online since:

August 2016

Export:

Price:

Permissions CCC:

Permissions PLS:

Сopyright:

© 2016 Trans Tech Publications Ltd. All Rights Reserved

Share:

Citation:

* - Corresponding Author

[1] E. Chiellini, A. Corti, S. D'Antone and R. Baciu, Oxo-biodegradable carbon backbone polymers: oxidative degradation of polyethylene under accelerated test conditions, Polym Degrad Stab. 91 (2006) 2739–2747.

DOI: 10.1016/j.polymdegradstab.2006.03.022

Google Scholar

[2] Maryudi, A. Hisyam, R.M. Yunus and M.D.H. Bag, Thermo-oxidative degradation of high density polyethylene containing manganese laurate, Int J Eng Res Appl. 3 (2013) 1156–1165.

Google Scholar

[3] P.K. Roy, P. Surekha, C. Rajagopal, S.N. Chatterjee and V. Choudhary, Effect of benzil and cobalt stearate on the aging of low-density polyethylene films, Polym Degrad Stab. 90 (2005) 577–585.

DOI: 10.1016/j.polymdegradstab.2005.01.017

Google Scholar

[4] P.K. Roy, P. Surekha, C. Rajagopal and V. Choudhary, Effect of cobalt carboxylates on the photo-oxidative degradation of low density polyethylene Part–I, Polym Degrad Stab. 91 (2006) 1980–(1988).

DOI: 10.1016/j.polymdegradstab.2006.02.007

Google Scholar

[5] B. Singh and N. Sharma, Mechanistic implications of plastic degradation, Polym Degrad Stab. 93 (2008) 561–584.

Google Scholar

[6] I. Jakubowicz, Evaluation of degradability of biodegradable polyethylene (PE), Polym Degrad Stab. 80 (2002) 39–43.

Google Scholar

[7] D. Wiles and G. Scott, Polyolefins with controlled environmental degradability, Polym Degrad Stab. 91 (2006) 1581–1592.

DOI: 10.1016/j.polymdegradstab.2005.09.010

Google Scholar

[8] C. Abrusci, J.L. Pablos, T. Corrales, J. López-Marín , I. Marín and F. Catalina, Biodegradation of photo-degraded mulching films based on polyethylenes and stearates of calcium and iron as pro-oxidant additives, Int Biodeterior Biodegrad. 65 (2011).

DOI: 10.1016/j.ibiod.2010.10.012

Google Scholar

[9] T. Muthukumar, A. Aravinthan and M. Doble, Effect of environment on the degradation of starch and pro-oxidant blended polyolefins, Polym Degrad Stab. 95 (2010) 1988–(1993).

DOI: 10.1016/j.polymdegradstab.2010.07.017

Google Scholar

[10] T. Manangan, S. Shawaphun, D. Sangsansiri, J. Changcharoen and S. Wacharawichanant, Nano-sized titanium dioxides as photo-catalysts in degradation of polyethylene and polypropylene packagings, Sci. J. UBU. 1 (2010) 14–20.

Google Scholar

[11] S. Shawaphun, T. Manangan and S. Wacharawichanant, Thermo- and photo-degradation of LDPE and PP films using metal oxides as catalysts, Adv Mater Res. 93 (2010) 505–509.

DOI: 10.4028/www.scientific.net/amr.93-94.505

Google Scholar

[12] B. Suresh, S. Maruthamuthu, A. Khare, N. Palanisamy, V.S. Muralidharan, R. Ragunathan, M. Kannan and M.K. Pandiyaraj, Influence of thermal oxidation on surface and thermomechanical properties of polyethylene, J Polym Res. 18 (2011) 2175–2184.

DOI: 10.1007/s10965-011-9628-0

Google Scholar

[13] R.D. Maalihan and B.B. Pajarito, Effect of colorant on tensile strength and carbonyl index of oxo-biodegradable low-density polyethylene films during thermal aging, Adv Mater Res. 1125 (2015) 235 – 239.

DOI: 10.4028/www.scientific.net/amr.1125.235

Google Scholar

[14] R.D. Maalihan and B.B. Pajarito, Effect of colorant, thickness, and pro-oxidant loading on degradation of low-density polyethylene films during thermal aging, J Plastic Film Sheet. 32(2) 124 – 139.

DOI: 10.1177/8756087915590276

Google Scholar