基于斜坡实验的高固含量推进剂药浆流变行为研究OA

The solid content in hydroxyl-terminated polybutadiene(HTPB)is usually extremely high(ϕ≥0.5),and there exists complex interactions between particles and binders as well as among particles.Its rheological properties are significantly different from those of solid-liquid systems with low and medium contents.In the present work,an inclined-plane rheometer was built to suit the specific properties of HTPB systems.Propellant substitutes with high-solid suspensions(ϕ=0.365～0.513)were prepared using high-viscosity hydroxyl-terminated polybutadiene(HTPB)as the binder and acrylate-styrene-acrylonitrile(ASA)particles as solids.A laser displacement sensor was used to measure the liquid-film thickness and surface velocity of the flows on the slope,and the explicit expressions for the power-law index n and consistency coefficient K were derived from the power-law model to establish the constitutive equation.The results show that n falls from 0.893 to 0.432 and K rises from 153.6 Pa·sn to 670.9 Pa·sn as ϕ increases from 0.365 to 0.513.These phenomena reflect strong shear-thinning behavior,and these model parameters,i.e.n and K,exhibit exponential dependence on solid content ϕ.Empirical correlations for n and K as functions of ϕ are now available with a prediction error below 10%.The method provides a simple and reliable means of characterizing high-solid HTPB propellants and delivers the essential physical property data required for equipment design and process optimization.