Effect of constant viscosity agent on molecular structure and dynamic mechanical properties of raw constant viscosity natural rubber

The Mooney viscosity, relative molecular mass and its distribution, dynamic mechanical properties of raw constant viscosity natural rubber prepared with hydroxylamine hydrochloride and semicarbazide hydrochloride as constant viscosity agent were measured with Mooney viscometer, gel permeation chromatograph and rubber processing analyzer, respectively. The results showed that compared to semicarbazide hydrochloride, hydroxylamine hydrochloride had a more significant impact on Mooney viscosity and relative molecular mass of natural rubber. The Mooney viscosity, relative molecular mass of hydroxylamine hydrochloride-based natural rubber were evidently lower than those of natural rubber, and the increase rate of elastic modulus of the former was less than that of the latter with increasing frequency at lower frequency, the increase rate of loss factor of the former was larger than that of the latter with increasing strain, and the sensitivity of shear rate for complex viscosity of the former was smaller than that