[Influence of sterilization treatments on continuous carbon-fiber reinforced polyolefin composite]

To evaluate the influence of sterilization treatment on continuous carbon-fiber reinforced polyolefin composite (CFRP) so as to provide experimental reference for selection of sterilization method for CFRP.

Seventy bars of CFRP were divided into 7 equal groups to undergo sterilization by autoclave, 2% glutaraldehyde soaking, 75% alcohol soaking, ethylene oxide sterilization, and Co-60 gamma ray irradiation of the dosages 11 kGy, 25 kGy, and 18 kGy respectively, and another 10 bars were used as blank controls. Then the bars underwent three-point bending test and longitudinal compression test so as to measure the biomechanical changes after sterilization treatment, including the maximum load, ultimate strength, and elastic modulus.

Three-point bending test showed that the levels of maximum load of the all experimental groups were lower than that of the control group, however, only those of the 3 Co-60 irradiation groups were significantly lower than that of the control group and that Co-60 radiation lowered the level of maximum load dose-dependently; and that the levels of ultimate strength of all the all experimental groups were lower than that of the control group, however, only those of the 3 Co-60 groups were significantly lower than that of the control group and that the higher the dosage of Co-60 radiation the lower the level of ultimate strength, however, not dose-dependently. The elastic modulus of the Co-60 25 KGy group was significantly higher than that of the control group, and there was no significant difference in the level of ultimate strength among the other groups. Longitudinal compression test showed that the levels of maximum load and ultimate strength of the 3 Co-60 irradiation groups, autoclave group, and circular ethylene groups were significantly lower than that of the control group, and there was no significant difference in elastic modulus among different groups.

During sterilized package of CFRP products produced in quantity autoclave sterilization and Co-60 gamma ray irradiation sterilization should be avoided. Ethylene oxide is proposed as the best sterilization method. If gamma ray irradiation is to be used further technology improvement is necessary.