Abstract: Variation relationships were studied between quality indexes such as mass fraction, acid value, refractive index, and viscosity of p-menthane hydrogen peroxide (PMHP) products with storage days, and major influencing factors to the quality stability of PMHP were studied as well. The results shown that the correlation coefficients (r_t) of PMHP mass fraction, acid value, refractive index, and viscosity to the storage days are -0.8807, 0.9867, 0.9348 and 0.2236, respectively; the correlation coefficients (r_x) of variations of acid value, refractive index, and viscosity to the variation of PMHP mass fraction in the storage are -0.9454, -0.9695 and -0.4240, respectively. The results also shown that the acid value is an important quality index, and that the resistance and formation of more acidic matters in the product is a key influencing factor to the quality stability of PMHP. The initial acid value is suggested to be regulated to a suitably lower level as a key influencing factor, so that it would effectively reduce the variations of acid value and PMHP mass fraction under storage, then increase the quality stability.

Key words: p-menthane hydrogen peroxide (PMHP), quality stability, acid value