MSA  Vol.5 No.13 , November 2014
Rheological and Thermal Behavior of High-Density Polyethylene (HDPE) at Different Temperatures
ABSTRACT
In the present work, rheological properties of HDPE samples were measured at temperatures of 150°C, 190°C and 230°C. It was shown, by oscillatory tests, at low frequencies, that, for temperatures of 150°C and 190°C, there was a predominance of the viscous behavior over the elastic one. At 230°C, there was a predominance of the elastic contribution, and there was an increase of the molar mass compared with the ones obtained from the tests at 150°C and 190°C. The results obtained from the temperature ramp oscillatory test showed that, up to around 248°C, the viscous behavior prevailed, the opposite being observed at higher temperatures. At 230°C the sample showed significantly lower values of strain when compared with the ones observed at 150°C and 190°C. Oxidative induction time (OIT), melting point and degree of crystallinity were determined by differential scanning calorimetry (DSC). The DSC results and the rheological measurements showed a completely different behavior for the HDPE samples at 230°C compared with the 150°C and the 190°C ones, suggesting that HDPE, at the temperature of 230°C, underwent thermo-oxidative degradation with the initial predominance of crosslinking.

Cite this paper
Erbetta, C. , Manoel, G. , Oliveira, A. , Silva, M. , Freitas, R. and Sousa, R. (2014) Rheological and Thermal Behavior of High-Density Polyethylene (HDPE) at Different Temperatures. Materials Sciences and Applications, 5, 923-931. doi: 10.4236/msa.2014.513094.
References
[1]   Cheng, J.J. (2008) Mechanical and Chemical Properties of High Density Polyethylene: Effects of Microstructure on Creep Characteristics. Doctoral Thesis, University of Waterloo, Canada.

[2]   Parrondo, A., Allen, N.S., Edge, M., Liauw, C.M., Fontán, E. and Corrales, T. (2002) Additive Interactions in the Stabilization of Film Grade High-Density Polyethylene. Part I: Stabilization and Influence of Zinc Stearate during Melt Processing. Journal of Vinyl & Additive Technology, 8, 75-89.
http://dx.doi.org/10.1002/vnl.10349

[3]   De Paoli, M.A. (2008) Degradacao e Estabilizacao de Polímeros. Artliber Editora Ltda, Sao Paulo.

[4]   Mesquita, F.A. (2010) Modification of High Density Polyethylene Properties after Different Extrusion Conditions. M.Sc. Dissertation, University of Sao Paulo, Sao Paulo.

[5]   Mendes, L.A.A. (2006) Study of Mechanisms of Degradation of the Polyethylene in Primary Recycling. Doctoral Thesis, University of Minho, Braga.

[6]   Ferry, J.D. (1980) Viscoelastic Properties of Polymers. Wiley, New York.

[7]   Peacock, A.J. (2000) Handbook of Polyethylene—Structures, Properties and Applications. Marcel Dekker, New York.

[8]   Understanding Rheology of Thermoplastic Polymers (TA Instruments) (2004)
http://www.tainstruments.com/pdf/literature/AAN013_V_1_U_Thermoplast.pdf

[9]   Erbetta, C.D.C., Silva, M.E.S.R., Freitas, R.F.S. and Sousa, R.G. (2013) Evaluation of Thermal, Chemical and Rheological Properties of High Density Polyethylene (HDPE) Additives with Pro-Degrading Agent, after Processing. Proceedings of the 12th Brazilian Congress of Polymers, Florianópolis, 22-26 September 2013, 1-4.

[10]   Cruz, S.A., Farah, M., Zanin, M. and Bretas, R.E.S. (2008) Evaluation of Rheological Properties of Virgin HDPE/ Recycled HDPE Blends. Polímeros: Ciência e Tecnologia, 18, 144-151.
http://dx.doi.org/10.1590/S0104-14282008000200012

[11]   Guimaraes, M.J.O.C., Coutinho, F.M.B., Rocha, M.C.G., Bretas, R.E.S. and Farah, M. (2003) Rheology of High Density Polyethylene Toughened with Elastomeric Polyethylene. Polímeros: Ciência e Tecnologia, 13, 135-140.
http://dx.doi.org/10.1590/S0104-14282003000200013

[12]   Snyder, R.G. (1980) Spectroscopic Methods—Methods in Experimental Physics. Vol. 16, Part A, Academic Press, New York.

[13]   Pinheiro, L.A., Chinelatto, M.A. and Canevarolo, S.V. (2004) The Role of Chain Scission and Chain Branching in High Density Polyethylene during Thermo-Mechanical Degradation. Polymer Degradation and Stability, 86, 445-453.
http://dx.doi.org/10.1016/j.polymdegradstab.2004.05.016

[14]   Hinsken, H., Moss, S., Pauchet, J. and Zweifel, H. (1991) Degradation of Polyolefins during Melt Processing. Polymer Degradation and Stability, 34, 279-293.
http://dx.doi.org/10.1016/0141-3910(91)90123-9

[15]   Scuracchio, C.H, Bretas, R.E.S. and Isayev, A.I. (2004) Blends of PS with SBR Devulcanized by Ultrasound: Rheology and Morphology. Journal of Elastomers and Plastics, 36, 45-75.
http://dx.doi.org/10.1177/0095244304039913

[16]   Torres, A.A.U. (2007) Physicochemical Ageing of HDPE Pipes Assigned to the Transportation of Petroleum Derivatives. M.Sc. Dissertation, Catholic University of Rio de Janeiro, Rio de Janeiro.

[17]   Moss, S. and Zweifel, H. (1989) Degradation and Stabilization of High Density Polyethylene during Multiple Extrusions. Polymer Degradation and Stability, 25, 217-245.
http://dx.doi.org/10.1016/S0141-3910(89)81009-2

[18]   Azevedo, J.B., Chávez, M.A. and Rabello, M.S. (2010) The Effect of a Crosslinking Agent on the Morphology and Physical and Mechanical Properties of Polymer Foams Based on EVA and EPDM. Polímeros: Ciência e Tecnologia, 20, 407-414.
http://dx.doi.org/10.1590/S0104-14282011005000002

[19]   Hoàng, E.M., Allen, N.S., Liauw, C.M., Fontán, E. and Lafuente, P. (2006) The Thermo-Oxidative Degradation of Metallocene Polyethylenes: Part 2: Thermal Oxidation in the Melt State. Polymer Degradation and Stability, 91, 13631372.
http://dx.doi.org/10.1016/j.polymdegradstab.2005.07.018

 
 
Top