title: Controlled manipulation of elastomers with radiation: Insights from multiquantum nuclear-magnetic-resonance data and mechanical measurements.
abstract: Filled and cross-linked elastomeric rubbers are versatile network materials with a multitude of applications ranging from artificial organs and biomedical devices to cushions, coatings, adhesives, interconnects, and seismic-isolation, thermal, and electrical barriers. External factors such as mechanical stress, temperature fluctuations, or radiation are known to create chemical changes in such materials that can directly affect the molecular weight distribution (MWD) of the polymer between cross-links and alter the structural and mechanical properties. From a materials science point of view it is highly desirable to understand, affect, and manipulate such property changes in a controlled manner. Unfortunately, that has not yet been possible due to the lack of experimental characterization of such networks under controlled environments. In this work we expose a known rubber material to controlled dosages of γ radiation and utilize a newly developed multiquantum nuclear-magnetic-resonance technique to characterize the MWD as a function of radiation. We show that such data along with mechanical stress-strain measurements are amenable to accurate analysis by simple network models and yield important insights into radiation-induced molecular-level processes.
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94551, USA. amaiti@llnl.gov
authors.forename: A
authors.initials: A
authors.lastname: Maiti
authors.forename: T
authors.initials: T
authors.lastname: Weisgraber
authors.forename: L N
authors.initials: LN
authors.lastname: Dinh
authors.forename: R H
authors.initials: RH
authors.lastname: Gee
authors.forename: T
authors.initials: T
authors.lastname: Wilson
authors.forename: S
authors.initials: S
authors.lastname: Chinn
authors.forename: R S
authors.initials: RS
authors.lastname: Maxwell
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D003432:Cross-Linking Reagents; D020724:Elastomers / Q000737:chemistry* / Q000528:radiation effects; D004864:Equipment and Supplies; D005720:Gamma Rays; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008970:Molecular Weight; D011108:Polymers / Q000737:chemistry; D015203:Reproducibility of Results; D012408:Rubber; D013242:Sterilization; D013314:Stress, Mechanical; D013696:Temperature; D013718:Tensile Strength
chemical_list: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D020724:Elastomers; D011108:Polymers; D012408:Rubber