Three kinds of initiators (sodium hydroxide

sodium caprolactamate and caprolactam magnesium bromide) were selected to react respectively with microcrystalline cellulose (MCC) under vacuum at 150 ℃ for analyzing the mechanism of the severe retardation and discoloration in the reactive processing of anionic polyamide-6 and ramie fiber

with using conventional sodium initiators.Then the changes of the sodium caprolactamate (C10) and MCC before and after reaction were analyzed using Fourier translation infrared spectroscopy (FTIR)

atomic absorption spectroscopy (AAS)

X-ray diffraction (XRD) and nuclear magnetic resonance spectroscopy (NMR)

and it was concluded that the retardation and discoloration were mainly caused by the special byproducts generated from the peeling reaction of cellulose in alkaline and high-heat conditions

which were easy to react with anions dissociated from initiator

resulting in the consumption of the initiators

so as to make the end of polymerization of anionic polyamide-6.In addition

the initiator caprolactam magnesium bromide (C1)

due to low-activity and weak-alkalinity

weakened the peeling reaction and the reaction with the active groups on the byproducts

and thus the retardation and discoloration were improved significantly

which were the most important challenge during the reactive processing.Finally

the goal was achieved for manufacturing the ramie fiber-reinforced anionic polyamide-6 composites by reactive processing.