Synthesis And Property Investigation Of Polybutadiene-based Polyurethane Elastomer

Polybutadiene-based polyurethane elastomer is commonly used as a composite solid propellant adhesive. HTPBs as one of its main raw material plays a decisive role. In recent years, with the rapid development of China’s aerospace industry, HTPBs’ composite solid propellants develop in the direction toward the high-performance, especially with the increasing solid content, mechanical properties and process performance of the propellants becoming an urgent key technologies to be resolved, so the performance of HTPBs puts forward higher requirements. In domestic, HTPBs are produced by free radical polymerization of butadiene using hydrogen peroxide as initiator and alcohol as solvent (abbreviated as FHTPB). This technology is difficult to control the molecular weight, hydroxyl type and distribution functionality of products, which having broad molecular weight distribution, undefined molecular weight and hydroxyl value, high viscosity and wide gaps, especially obvious inferior in scale experiment lead to low-grade mechanical properties of HTPBs. The anionic solution polymerization technologies are controlled polymerization techniques. AHTPB with narrow molecular weight distribution, low viscosity, controllable microstructure relative content, functionality close to2can be synthesized. Although the technology can solve the problem of quality control, but between AHTPBs and FHTPBs is different, AHTPBs can not directly replace FHTPBs as a solid propellant binder. AHTPBs is a linear molecule, the molecule is almost bifunctional molecules in the reaction with TDI, the chain extension reaction can occur, and the chemical cross-linking can not occur, therefore performance is not or not completely cured in a curing. The AHTPB-based elastomer rare has been reported, so it’s preparation and properties remains to be further studied.This paper summarizes the network structure and micro-phase separation structure and its influencing factors such as HTPBs performance, isocyanate type, chain extender type, preparation methods and curing parameters impact on polybutadiene-based polyurethane elastomer performance. On this basis, the choice of three isocyanate as a curing agent to prepare the AHTPB-based elastomer is determined using infrared spectroscopy, DSC, DMA and other methods to characterize the polyurethane elastomer’s propertity. HTPBs’ microscopic structure, molecular weight and molecular weight distribution and the distribution of functionality impact on the crosslinked network structure and mechanical properties of the elastomer correlation are discussed, between uniformity of the crosslinked structure and mechanical properties corelation are discussed.