Indexing
All Issues
Submission
Author Guidelines
Reviewers
Editorial Members
Publication Fee
Vol.2 , No. 1, Publication Date: Feb. 24, 2016, Page: 1-9
 are provided with many properties of elastomeric or rubbery materials, but can be processed with the thermoplastic processing methods; they are one of the fastest growing polymers materials which combine the elastic and mechanical properties of crosslinked rubbers with the melt processability of thermoplastics. In addition, TPEs find a lot of applications in automotive, buildings and construction, wires and cables, etc.; besides their ability to reuse and recycle the production scrap and waste. Polypropylene (Pp) is a commodity, with high melting point, high chemical resistance, low density, with a balance between physical and mechanical properties and easy processing at low cost. Nevertheless, Pp shows limitations for some special applications, in terms of impact resistance; in order to minimize this characteristic, an impact modifier, as Ethylene Propylene Diene Terpolymer (Epdm) can be used. Due to different polarity and structure between the thermoplastic and elastomeric phases, most thermoplastic elastomers are incompatible. Poor interfacial adhesion and high interfacial tension between rubber and thermoplastic phases are main reasons for incompatibility of these systems; in case of Pp and Epdm, there is a relatively low interfacial tension (driving force for the transformation of a co-continuous structure into a dispersed one) between Pp and Epdm (approximately 0.3 mN/m), reducing the rate of breakup and facilitating the formation of a continuous structure. Pp/Epdm blends are completely recyclable and reusable, safe to the environment, thus improving the overall profitability of the process. Besides a higher impact resistance shown by Pp/Epdm blends, it is possible that Epdm incorporation in Pp causes a reduction in tensile resistance. In order to eliminate this interference and assuring a more comprehensive application in automotive, buildings and construction, Pp/Epdm blends, rubber contents ranging from zero to 30% (thirty percent), were subjected to gamma-irradiation, within doses from 5 to 20 kGy. Isotactic Pp was considered for this work. Characterization assessments included mechanical, thermal and rheological essays.&picture=http://www.aascit.org/aascit/decorators/img/journal/891.jpg)
| [1] | Elizabeth C. L. Cardoso, Center for Chemical and Environmental Technology (CQMA), Nuclear and Energy Research Institute (IPEN / CNEN – SP), São Paulo, Brazil. |
| [2] | Sandra R. Scagliusi, Center for Chemical and Environmental Technology (CQMA), Nuclear and Energy Research Institute (IPEN / CNEN – SP), São Paulo, Brazil. |
| [3] | Ademar B. Lugão, Center for Chemical and Environmental Technology (CQMA), Nuclear and Energy Research Institute (IPEN / CNEN – SP), São Paulo, Brazil. |
Thermoplastic elastomers (TPEs) are provided with many properties of elastomeric or rubbery materials, but can be processed with the thermoplastic processing methods; they are one of the fastest growing polymers materials which combine the elastic and mechanical properties of crosslinked rubbers with the melt processability of thermoplastics. In addition, TPEs find a lot of applications in automotive, buildings and construction, wires and cables, etc.; besides their ability to reuse and recycle the production scrap and waste. Polypropylene (Pp) is a commodity, with high melting point, high chemical resistance, low density, with a balance between physical and mechanical properties and easy processing at low cost. Nevertheless, Pp shows limitations for some special applications, in terms of impact resistance; in order to minimize this characteristic, an impact modifier, as Ethylene Propylene Diene Terpolymer (Epdm) can be used. Due to different polarity and structure between the thermoplastic and elastomeric phases, most thermoplastic elastomers are incompatible. Poor interfacial adhesion and high interfacial tension between rubber and thermoplastic phases are main reasons for incompatibility of these systems; in case of Pp and Epdm, there is a relatively low interfacial tension (driving force for the transformation of a co-continuous structure into a dispersed one) between Pp and Epdm (approximately 0.3 mN/m), reducing the rate of breakup and facilitating the formation of a continuous structure. Pp/Epdm blends are completely recyclable and reusable, safe to the environment, thus improving the overall profitability of the process. Besides a higher impact resistance shown by Pp/Epdm blends, it is possible that Epdm incorporation in Pp causes a reduction in tensile resistance. In order to eliminate this interference and assuring a more comprehensive application in automotive, buildings and construction, Pp/Epdm blends, rubber contents ranging from zero to 30% (thirty percent), were subjected to gamma-irradiation, within doses from 5 to 20 kGy. Isotactic Pp was considered for this work. Characterization assessments included mechanical, thermal and rheological essays.
Keywords
TPE, PP, EPDM, Gamma-Radiation
Reference
| [01] | ASTM D-256-10. Standard Test Methods for Determining the Izod Pendulum Impact Resistance of Plastics, (2010). |
| [02] | ASTM D-638-08. Standard Test Method for Tensile Properties of Plastics, (2008). |
| [03] | ASTMD-1238-13. Standard Test Method for Melt Flow Rates of Thermoplastics by Extrusion Plastometer, (2013). |
| [04] | ASTM E-1641-07. Standard Test method for Decomposition Kinetics by Thermogravimetry, (2007). |
| [05] | ASTM D-3418-08. Standard Test method for Transition Temperatures and Enthalpies of Fusion and Crystallization of Polymers by Differential Scanning Calorimetry, (2008). |
| [06] | I. Banik and A. K. Bhowmick (2000) Effect of electron beam irradiation on the properties of crosslinked rubbers, Radiation Physics and Chemistry, 58 (3), 293-298. |
| [07] | J. Bik, W. Głuszewski, W. M. Rzymski and Z. P. Zagórski (2003) EB radiation crosslinking of elastomers, Radiation Physics and Chemistry, 67 (3-4), 421-423. |
| [08] | N. Dély, Y. Ngono-Ravache, J. M. Ramillon and E. Balanzat (2005) Oxygen consumption in EPDM irradiated under different oxygen pressures and at different LET, Nuclear Instruments and Methodsin Physics Research, B 236 (1-4), 145-152. |
| [09] | S. K. De, A. K. Bhowmick (1990) Thermoplastic elastomers from rubber plastic blend, Horwood, London, 520-554. |
| [10] | P. Ezzati et al (2008) Correlation between the rheological behavior and morphology of PP/EPDM blend in various dynamic vulcanization systems, Iran Polym. J., 17, 1-8. |
| [11] | Osiris W. Guirguis, M. H. Moselhey (2012) Thermal and structural studies of poly (vinyl alcohol) and hydroxypropylcellulose blends, Natur. Scienc. vol 4, Nr 1, 57-67. |
| [12] | FiratHacioglu (2010) Degradation of EPDM via gamma irradiation and possible use of EPDM in radioactive waste management – Thesis - pp. 89-92. |
| [13] | A. R. Jalilvand et al (2007) Using devulcanized EPDM in PP/HDPE/EPDM ternaryblend: mechanical properties and morphology, Iran Polym. J, 16, 637- 644. |
| [14] | N. R. Legge, G. Holden and H. E. Schroeders (1987) Thermo-plastic elastomer: A comprehensive review, Hanser, Munich, 161-178. |
| [15] | E. Martuscelli (1995) Structure and properties of PP/elastomer blends, Polypropylene Structure, Blends and Composites, 95-140. |
| [16] | Tam T. M. Phan, A. J. Denicola, Jr and L. S. Schadler (1997) The Effect of Addition of Polyoxypropylenediamine on the Morphology and Mechanical Properties of Maleated Polypropylene/Maleated Rubber Blends, Polymer Engineering and Science, vol. 68, 1451-1472. |
| [17] | L. Torre; J. M. Kenny (2000) Kinetic Analyses of the thermal degradation of PP-EPDM blends, Rubber Chemistry and Technology, 73: 694-705. |
| [18] | T. Zaharescu et al (2010) Qualification of ethylene-propylene elastomers for nuclear applications, Journal of Advanced Researchin Physics, 1 (1), 1 – 6. |
| [19] | R Zhao; G. Dai (2002) Mechanical property and morphology comparison between elastomer and poly (propylene) / maleic anhydride eg-ethylene-propylene- diene monomer, J. Appl. Polym. Sci., 86, 2486-2491. |
