Radiation-resistant plastic

Radiation In general, plastics are superior to elastomers in radiation resistance but are inferior to metals and ceramics. The materials that will respond satisfactorily in the range of I010 and 10n erg per gram include... 

The presence of aromatic groups in polymers greatly reduces their radiation sensitivity. Aromatic polysulfones are commercially important engineering plastics with high temperature resistance and also show good radiation resistance (16). Development of polymers with improved radiation resistance should be possible by copolymerization of other aromatic structures into the chain. 

HNS has a uniquely small critical diam ( 0.020 inch), i s practically insensitive to electrostatic spark, is less sensitive to impact than Tetryl, is radiation resistant, and is the only commercially available expl meeting the expl sensitivity requirements of the Fuze Design Safety Criteria of all three services (Ref 8) Uses HNS is used as a heat-resistant booster expl. It is sufficiently insensitive to heat, impact, and electrostatic spark to be used in mild detonating fuse (MDF) end couplers St end boosters. It may find application in leads and in plastic-bonded HE s... 

In general, plastics are superior to elastomers in radiation resistance but are inferior to metals and ceramics. The materials that will respond satisfactorily in the range of 1010 and 1011 erg per gram are glass and asbestos-filled phenolics, certain epoxies, polyurethane, polystyrene, mineral-filled polyesters, silicone, and furane. The next group of plastics in order of radiation resistance includes polyethylene, melamine, urea formaldehyde, unfilled phenolic, and silicone resins. Those materials that have poor radiation resistance include methyl methacrylate, unfilled polyesters, cellulosics, polyamides, and fluorocarbons. 

These plastics, also known as pyrrones, are experimental materials prepared from aromatic dianhydrides and aromatic tetraamines. The polymer syntheses provide soluble prepolymers that are converted to the pyrrone structures by thermal or chemical dehydration. The precursors can be used to cast films or coatings, or can be molded under very high pressures into filled or unfilled forms. The pyrrones combine some of the best properties of the polybenzimidazoles and polyimides. The pyrrone films are exceptionally radiation resistant and retain their strength properties after 10,000 megarads of 1-MeV electrons. 

Seguchi, T. Morita, Y. Radiation resistance of plastics and elastomer, Polymer Handbook, 1998, VI 583. 

DPA are excellent AO and HS in various rubbers and plastics, lubricating greases and oils [27], They have some antifatigue effect and provide no antiozonant protection [1], Their photostabilization activity is rather low. DPA may be used in radiation resistant polymer compositions for cable coatings in nuclear power plants [28]. Various 4,4 -disubstituted DPA contain a fert-alkyl (e.g. 1,1,3,3-tetramethylbutyl 9a, 1,1-dimethylethyl or their combinations), other alkyls or aralkylgroups (e.g. a,a-dimethylbenzyl, 9b) [1,3,24]. A tertiary amine 3-[(diphenylamino)methyl]-5-[(diphenylaminomethyl)thio]-l,3,4-thiadiazolidine-2 (14) was proposed as AO for rubbers [29],... 

T. Seguchi, T. Sasuga, K. Yoshida, H. Yagyu and Y. Yamamoto, EIM 82-114 (1982) (in Japanese) T. Seguchi and Y. Morita, Radiation resistance of plastics and elastomers , in Polymer Handbook, VI-583, John Wiley and Sons, New York (1999)... 

Often low-heat-resistant resins show the greatest radiation resistance. Some otherwise excellent plastics are known to be rather strongly affected by high-energy radiations. These are polyvinylidene chloride, polymethylmethacrylate, polytetraflu-oroethylene, butyl rubber, etc. Fig. R.1 shows relative radiation resistance data for some of the more commonly used plastics and elastomers. 

The various materials (often polymers) have to be chosen such that they are sufficiently radiation resistant to withstand the sterilization dose. Under the dose conditions, needed for sterilization some polymers such as polyethylene, polystyrene, poly(ethylene terephthalate), polyurethanes, and epoxides maybe stable, whereas others such as polypropylene, poly(methyl methacrylate), polyvinyl chloride (PVC) may not. When the radiation stability of the plastic... 

As obvious from literature search, cell-cell contacts have been a focus of interest in cancer research for many years (Ruch and Trosko 2001 Trosko and Ruch 1998). Recently, the impact of cell-matrix interactions on tumor ceU resistance was evidently demonstrated in several ceU lines from different soUd and hematologic tumor entities in vitro. Dependent on the characteristics, the phenomena were caUed ceU adhesion-mediated radiation resistance (CAM-RR) or cell adhesion-mediated drug resistance (CAM-DR) (CoRDES and Meineke 2003 Dalton 2003 Dami-ANO et al. 1999). Most relevant for in vitro cancer research, this effect can easily be observed when comparing the radio- or chemosensitivity of cells plated on a conventional plastic culture dish with cells plated on different matrix proteins like fibronectin, coUagen, or laminin. The contact with ECM proteins and the altera-... 

Radiation resistance. Aurum has an exceptional radiation resistance since it behaves as a cross-hnked plastic despite being a thermoplastic polymer. See Table 10.5. 

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