Application of potassium persulfate/sodium dithionate redox system in graft weighting of silk

The weighted silk by grafting methacrylamide(MAA) using potassium persulfate(KPS) as an initiator is encountered with the problem of yellowing.Therefore,potassium persulfate(KPS)/sodium dithionite(SH) redox system initiator for graft weighting of silk was put forward in order to improve the whiteness of the weighted silk.The effect of various process parameters on the graft weighting rate was investigated.The results showed that KPS-SH redox system initiator provided a better whiteness than KPS only in MAA graft weighting of silk;and when the amount of MAA was 70%(o.w.f),the amount of KPS/SH molar ratio of initiator was 5%(on weight of monomer),molar ratio of KPS and SH was 10∶3,pH = 3,grafting is performed at 70 ℃ for 70 min,the graft weighting rate of the silk was basically the same as that with KPS only,but the whiteness was improved by 19 degrees.