What does gamma radiation do to plastic?
Gamma rays are a penetrating form of radiation which easily pass through plastics. They break the covalent bonds of DNA killing bacteria and other microbes exposed to the radiation. Ionizing rays of gamma radiation can cause following changes in polymers: Discolor or yellowing effect.
What are the effects of gamma radiation on cells?
Gamma radiation is well recognized as a potent carcinogen due to its potential of oxidative damage (Toule, 1987; Morgan et al., 1996). It causes a variety of lesions in DNA including single- and double-strand breaks, DNA-protein cross-links, oxidized bases and abasic sites (Cadet et al., 1999; UNSCEAR, 2000a).
What can gamma decay travel through?
Gamma rays are a radiation hazard for the entire body. They can easily penetrate barriers that can stop alpha and beta particles, such as skin and clothing. Gamma rays have so much penetrating power that several inches of a dense material like lead, or even a few feet of concrete may be required to stop them.
Is PTFE gamma stable?
Each of these resins can tolerate gamma radiation to varying degrees making them suitable for certain medical and analytical applications requiring sterility. PTFE, however, does not stand up to gamma radiation exposure well enough to be sterilized.
Can radiation destroy plastic?
While many pure plastics cannot absorb UV radiation, the presence of catalyst residues and other impurities (examples: oxygen, sodium) even at trace amounts, will often act as free radical receptors. Those free radicals can cause breaks in the polymer bonds.
Does radiation affect plastic?
Depending on the application, plastics can come into contact with different types of radiation, which under certain circumstances can have radiation effects on polymers. The shorter the wavelength of radiation, the higher the susceptibility of a plastic to damage.
Can the body repair radiation damage?
Cells, like the human body, have a tremendous ability to repair damage. As a result, not all radiation effects are irreversible. In many instances, the cells are able to completely repair any damage and function normally.
How does radiation harm the body?
Ionizing radiation—the kind that minerals, atom bombs and nuclear reactors emit—does one main thing to the human body: it weakens and breaks up DNA, either damaging cells enough to kill them or causing them to mutate in ways that may eventually lead to cancer.
Can PTFE be gamma sterilized?
PTFE does not hold up well at all in gamma radiation. As an example, 4Mrads of exposure reduces the tensile strength of the PTFE to 2% of it’s original value. A better fluoropolymer for gamma irradiation would be DuPon’ts Tefzel product which is known by the chemical moniker of ETFE.
Does UV break down plastic?
Benefits. UV energy absorbed by plastics can excite photons, which then create free radicals. While many pure plastics cannot absorb UV radiation, the presence of catalyst residues and other impurities will often act as receptors, causing degradation.
What are the effects of gamma radiation on plastics?
The effects of gamma irradiation on compositional changes in plastic films were reported by Demertzis and co-authors, who applied 44 kGy at several polymers. Since the late fifties radiation effects on polymers were studied and the relative stability of twelve types of plastics were published in 1961 (Krasnansky et al., 1961).
What are the effects of radiation on polypropylene?
Radiation, where mostly the effect of γ-rays has been investigated in the past, induce chain scission and degradation effects [1,2], resulting in a reduced melt viscosity and severe embrittlement. Parallel to that oxidized phenolic antioxidants results in discoloration; the material becomes yellow.
Are there materials that are compatible with gamma radiation?
Materials compatibility. Gamma radiation is compatible with many plastics, all metals, and glass (subject to color change). Some polymers, however, are affected either by embrittlement, discoloration, or degradation. Note that gamma rays generate free radicals that can further react and degrade the materials.
What happens to polymers when exposed to radiation?
It is well known that polymers can be cross-linked when exposed to radiation or chain scission as the opposite effect. Regarding packaging, there is a lot of interest since irradiation processing for sterilization is an increasing technology for varied items.
