Impact of initiator characteristics on the thermal stability of vinylidene chloride copolymers
- 49 Downloads
Two standard vinylidene chloride copolymers, the first containing approximately 9 mass% methyl acrylate and the second containing vinyl chloride at a nominal 15 mass% were prepared by radical suspension techniques using a series of peroxide and azo initiators (all of approximately the same half-life temperature for decomposition).
The nature of the initiator could impact the stability of the resulting polymer in two ways. Instability could be introduced either via end-group effects or by attack of residual initiator fragments on the finished polymer during isolation and residual monomer stripping. In this case, the relative thermal stability of the resins produced was assessed by exposing samples to heat and shear in an air environment in a two-roll mill (Brabender Prep-Mill). The rate and extent of degradation was most readily apparent from color development during this treatment. The more thermally stable polymers were produced using initiator radicals that did not attack the polymer during isolation/stripping processes.
Keywordsdefect structures polymer thermal stability as a function of chain-end structure processing damage radical reactivity
Unable to display preview. Download preview PDF.
- 1.DeLassus, PT, Brown, WE, Howell, BA, et al. 1997Encyclopedia of Packaging Technology, 2nd Ed.John Wiley and Sons, Inc.New York958Google Scholar
- 2.Wessling, RA, Gibbs, DS, DeLassus, PT, Obi, BE, Howell, BA, et al. 1997KirkOthmer Encyclopedia of Chemical Technology, Vol. 24, 2nd Ed.John Wiley and Sons, Inc.New York883Google Scholar
- 7.DeLassus, PT, Strandburg, G, Howell, BA 1988Tappi J.71177Google Scholar