Journal List > Prog Med Phys > v.25(4) > 1098443

Shin and Choi: The Influence of E-beam Irradiation on POLY(ETHER-BLOCK-AMIDE) (PEBA, Pebax)

Abstract

Medical polymers require sterilization and must be able to maintain material properties for a specified shelf life. Sterilization can be achieved by using gamma or e-beam exposure. In this study, accelerated aging tests of poly(ether-block-amide) (PEBA) copolymer samples is presented. PEBA copolymer samples with different polyether content that result in Shore hardness of 35D to 72D, were sterilized using e-beam radiation followed by accelerated aging at 55oC. E-beam sterilization effect on molecular weight and mechanical property has performed and analyzed. The average molecular weight significantly reduced as a result of ageing. The enlarged proportion of low molecular weight chains in the aged samples is consistent with the generation of degradation products produced by oxidative chain scission. Also E-beam materials have shown decreased tensile strength and elongation. Overall, this study demonstrated that the medical grade PEBA was significantly affected by radiation exposure over aging time, particularly at high irradiation doses. For medical use in case of radiation sterilization required, it is recommended to avoid Pebax material. If Pebax material must be in use for medical device, recommend to use alternate sterilization method such as Ethylene Oxide sterilization.

References

1. ANSI/AAMI/ISO 11137. Sterilization of health care products-Requirements for validation androutine control-Radiation Sterilization (. 1994.
2. Pebax Atochem Pebax Technical Notice: Polyether Block Amides, Pebax Processing, Polyether Block Amides. Elf Atochem (. 2002.
3. Borg P, Boutillier J. Hot Melt Copolymers Exhibit High Cohesion and Compatibility. Adhesives Age, July (. 1986. ), pp.31–33.
4. Dixon D, Boyd A. Degradation and accelerated ageing of poly(ether block amide) thermoplastic elastomers. Polymer Engineering & Science (51): 2203–2209 (. 2011.
5. Faruque F, Lacavanne C. Anelastic and dielectric properties of polyether-polyamide copolymer PEBAX studied by a thermally stimulated depolarisation current method. J. Phys. D: Appl. Phys. (20): 939 (. 1987.
6. Boublil H, Okoroafor E, Belhoucine M, Rault J. Morphology of polyamide and polyether block amide blends. Polymer Engineering & Science (29): 679–684 (. 1989.
7. Alberola N. Micromechanical properties of polyether block amide copolymers, Journal of Applied Polymer Science (36): 787–804 (. 1988.
8. Alberola N, Vassel A, Helluin C. Mechanical relaxation processes in polyether block amide copolymers (PEBA), Makromolekulare Chemie. Macromolecular Symposia (23): 219–224 (. 1989.
9. Sorta E, Fortuna G. Poly(ester amide)-polyether block copolymers: preparation and some physcochemical properties. Polymer (21): 728–732 (. 1980.
10. Begenir A, Michielsen S, Pourdeyhimi B. Crystallization behavior of elastomeric block copolymers: Thermoplastic polyurethane and polyether-block-amide. Journal of Applied Polymer Science (111): 1246–1256 (. 2009.
11. Song Y, Yamamoto H, Nemoto N. Segmental Orientations and Deformation Mechanism of Poly(ether-block-amide) Films. Macromolecules (16): 6219–6226 (. 2004.
12. Clayden J, Pendlebury R. NMR study of the effect of electron beam processing on a poly(etherblock-amide). Polymer (42): 8373–8377 (. 2001.
13. Ding S, A Khare, Ling M, Sandford C, Woo L. Polymer durability estimates based on apparent activation energies for thermal oxidative degradation. ThermochimicaActa (367–368): 107–112 (. 2001.
14. Sterigenics Sterilization Alternatives: Electron Beam Radiation. Material Considerations, Irradiation Processing. (. 2004.
15. Hemmerich K.J. .:. General Aging Theory and Simplified Protocol for Accelerated Aging of Medical Devices. Medical Plastics and Biomaterials Magazine (. 1998.

Fig. 1.
Molecular weight analysis summary of Pebax 35Dpost e-beam & ageing.
pmp-25-205f1.tif
Fig. 2.
Molecular weight analysis summary of Pebax40Dpost e-beam & ageing.
pmp-25-205f2.tif
Fig. 3.
Molecular weight analysis summary of Pebax55Dpost e-beam & ageing.
pmp-25-205f3.tif
Fig. 4.
Molecular weight analysis summary of Pebax 75D post e-beam & ageing.
pmp-25-205f4.tif
Fig. 5.
Tensile strength property summary of Pebax 35D post e-beam & ageing.
pmp-25-205f5.tif
Fig. 6.
Elongation property summary of Pebax 35D post e-beam & ageing.
pmp-25-205f6.tif
Table 1.
Material and e-beam radiation dose information.
Material E-beam condition
Pebax 35D Control
e-beam @ 50 kGy& aged 10 weeks
Pebax 40D Control
e-beam @ 35 kGy& aged 10 weeks
e-beam @ 50 kGy& aged 10 weeks
Pebax 55D Control
e-beam @ 35 kGy& aged 10 weeks
e-beam @ 50 kGy& aged 10 weeks
Pebax 72D Control
e-beam @ 35 kGy & aged 10 weeks
Pebax 35D 80 kGy for all samples used for tensile test,
aged for 48 months.
Table 2.
Calculated accelerated exposure time for various desired aging time at multiple elevated storage temperature
Accelerated Time (Days)
Desired aging time   6 month 1 year 2 year 3 year
(Days)   183 365 730 1095
Accelerated aging 60 14 27 53 79
temperature (°C) 55 19 38 75 112
  50 27 53 105 158
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