Although Ziegler-Natta(Z-N)polyolefins have been widely used as raw materials to produce pharmaceutical or food packaging,the migration of acid scavengers,an additive usually introduced in Z-N polyolefins,from the pac...Although Ziegler-Natta(Z-N)polyolefins have been widely used as raw materials to produce pharmaceutical or food packaging,the migration of acid scavengers,an additive usually introduced in Z-N polyolefins,from the packaging to its contents has not been reported.In this work,the migration of the two most used acid scavengers,calcium stearate(CaSt_(2))and zinc stearate(ZnSt_(2)),from a Z-N polypropylene random copolymer(PPR)into water during autoclaving at 121℃ were comparatively investigated.It was found that,for PPR plates containing 0.1 wt%CaSt_(2)or ZnSt_(2)(PPR-0.1CaSt_(2),PPR-0.1ZnSt_(2),respectively),the concentration of migrated calcium ion into water increased with autoclaving time,while that of zinc ion was much lower at same treatment durations and did not show a significant increase with treatment time.Interestingly,after removing all plates and acidification treatment,a considerable amount of stearic acid was detected in sterilized water for PPR-0.1ZnSt_(2),but no such significant stearic acid was detected in sterilized water for PPR-0.1CaSt_(2).Based on the structural evolution of the two soaps upon heating,possible mechanisms for the different migration behavior of CaSt_(2)and ZnSt_(2)from PPR into water during autoclaving treatment were proposed.Our results suggest that the migration issue of acid scavengers is worthy of attention in pharmaceutical packaging materials produced from Z-N polyolefins.展开更多
基金supported by the National Natural Science Foundation of China(No.52173056)the Science and Technology Program of Gansu Province,China(No.23ZDGA001).
文摘Although Ziegler-Natta(Z-N)polyolefins have been widely used as raw materials to produce pharmaceutical or food packaging,the migration of acid scavengers,an additive usually introduced in Z-N polyolefins,from the packaging to its contents has not been reported.In this work,the migration of the two most used acid scavengers,calcium stearate(CaSt_(2))and zinc stearate(ZnSt_(2)),from a Z-N polypropylene random copolymer(PPR)into water during autoclaving at 121℃ were comparatively investigated.It was found that,for PPR plates containing 0.1 wt%CaSt_(2)or ZnSt_(2)(PPR-0.1CaSt_(2),PPR-0.1ZnSt_(2),respectively),the concentration of migrated calcium ion into water increased with autoclaving time,while that of zinc ion was much lower at same treatment durations and did not show a significant increase with treatment time.Interestingly,after removing all plates and acidification treatment,a considerable amount of stearic acid was detected in sterilized water for PPR-0.1ZnSt_(2),but no such significant stearic acid was detected in sterilized water for PPR-0.1CaSt_(2).Based on the structural evolution of the two soaps upon heating,possible mechanisms for the different migration behavior of CaSt_(2)and ZnSt_(2)from PPR into water during autoclaving treatment were proposed.Our results suggest that the migration issue of acid scavengers is worthy of attention in pharmaceutical packaging materials produced from Z-N polyolefins.
