Journal of Polymer Science Part A General Papers · 1964 · 28 citations · 14 references
Natural SciencesChemistryMaterials ScienceOrganic ChemistryPolymer ChemistryPolymer MaterialsPolymer DegradationPolymer Physical ChemistryPolymer PhysicsPolymer StabilityPolymerization KineticsVolatile Organic CompoundsCarbon DioxidePolymer Degradation MechanismsPolymer Degradation Under RadiationPolymer Radiation DamageRadiation Chemistry Of PolymersReaction Quantum YieldsUltraviolet DegradationUv-induced Degradation
Abstract Thin films of poly(methyl acrylate) at room temperature have been photodegraded in air and in vacuum by radiation from a low‐pressure mercury source. Changes in intrinsic viscosities, ultraviolet absorption, and volatile products were followed as a function of the energy absorbed. Crosslinking occurs in both air and vacuum, but at a slower rate in air. The apparent quantum yield for random scission in air was 0.013 scissions per quantum absorbed. In air, carbonyl groups are formed along the backbone chain. Most of the volatile products studied appear to orginate from the ester groups in the polymer; formaldehyde, methanol, and methyl formate evolved at a constant rate for doses up to at least 2 × 10 20 quanta/g.; quantum yields for each were determined. Carbon dioxide forms in amounts increasing exponentially with dose. Small amounts of carbon monoxide, methane, and hydrogen were detected qualitatively, but monomer was not observed. A mechanism compatible with these findings is suggested.
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