Preparation, Characterization, and Rheological Behaviors of Polysiloxanes Presenting Densely Simple and Well‐Defined Short‐Branched Chains

In this paper, a series of polysiloxanes, presenting different contents of densely simple and well‐defined short‐branched chains (G 1 –G 5 ), are prepared by hydrosilylation of α,ω‐(dimethylvinylsiloxy)‐poly(dimethyl‐methylvinyl)siloxanes (P 1 –P 5 ) with 1,1,1,3,5,5,5‐heptamethyltrisiloxane (MD H M) and characterized by 1 H and 29 Si nuclear magnetic resonance, Fourier transform‐infrared spectroscopy, Abbe refractometry, gel permeation chromatography, and differential scanning calorimetry. The rheological behaviors of the G 1 –G 5 products are investigated to study the influences of the short‐branched chains. The rheological parameters including non‐Newtonian index ( n ) and the flow activation energy (Δ E η ) are obtained and discussed. It is observed that the G 1 –G 5 polymers belonged to pseudoplastic fluids and the Δ E η values of the G 1 –G 5 products are significantly influenced by the short‐chain branching degree of the polymers.