Volatile products and new polymer structures formed on 60Co γ-radiolysis of poly(lactic acid) and poly(glycolic acid)

Thermal stability of poly(lactic acid) before and after γ-radiolysis

“…Previous studies on the radiolysis of PLA 9,10 have demonstrated that it undergoes chain scission on g-radiolysis, with the loss of ester links and the evolution of CO and CO 2 . In addition, a range of new saturated and unsaturated chain-ends have been identi®ed following radiolysis, but it is apparent that these new chain-ends are incapable of premature initiation of any thermal degradation reaction.…”

Molecular characterization and crystallization behavior of peroxide-induced slightly crosslinked poly(L-lactide) during extrusion

“…However, the poor processability of PLLA often limits its applicability to extrusion molding, blow molding and form molding. To overcome this disadvantage, various methods have been used to introduce a branched architecture into the PLLA, including chemical crosslinking, 1-4 radiation-induced crosslinking 1, [5][6][7] and peroxide-induced crosslinking. [1][2][3][4][8][9][10][11][12][13][14] Among those methods, the peroxide-induced crosslinking process by the addition of a small amount of peroxide to PLLA during extrusion has been widely accepted because of its simplicity.…”

Contamination from Sterilization Procedures

“…Moreover, different radiolysis mechanisms take place when PlGA or PlA are irradiated in the presence of a drug. The authors presumed that this phenomenon can occur in FIGURE 12.3 Plots of the gas yield for CO (a), CO 2 (b), and CH 4 (c) evolved on irradiation of l-PlA to different doses [29]. In terms of polymer stability, the radical scavenging properties of drugs may be worthwhile, but considering the entire product and depending on the drug, the formation of radiolysis species from drug decomposition can be even worse than the decomposition of the polymer itself.…”