Progress on the Preparation and Characterization of Some Alkynediol Oxalate Polymers
Abstract
The mechanism and effects of the interaction of high energy laser radiation with polymeric materials are of great interest to the military. One application is in the area of personnel protection from the hazards of directed energy weapons (DEW). Srinivasan and Leigh 1 have studied the action of far-ultraviolet laser radiation on poly(ethylene terephthalate) (PET) films. Irradiation of the film caused etching to PET and formed gases such as CO, CO2, H2 and volatile organics such as benzene. The absorption of laser radiation leads to a very high concentration of free radicals in the surface layers of the PET film shortly afterward. The photoproducts (possibly in vibrationally excited states) are then ejected from the film surface and probably carry away the excess energy of the photon pulse. The result is that the photoetched film undergoes no significant temperature increase. Srinivasan and Leigh term this process an 'ablation'. Polyesters or polycarbonates should afford a greater degree of protection from a CO2 laser than other polymer types. Synthetic efforts toward more effective ablative polymers are described. Poly (1,4-but-2- ynedidyl) oxalate was prepared by transesterification of butyne-1,4-diol and diethyl oxalate. End group analysis by NMR indicated that average molecular weights were low. Several other synthetic procedures were investigated to increase the molecular weight of the polymer and are discussed. The related diacetylenic polymer poly (1,6-hexa-2,4-diyne)-diyloxalate, prepared by transesterification, could not be characterized because of the extreme thermal lability of it or a precursor. Keywords: Oxalate polymers, Acetylenic polymers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 11, 1988
- Accession Number
- ADA212076
Entities
People
- D. E. Remy
- J. W. Cullen
Organizations
- United States Army Soldier Systems Center