Preparation and characterization of polyurethane damping materials derived from mixed-base prepolymers containing numerous side methyls

Abstract

AbstractPolyurethane (PU) damping materials were prepared by mixed-base PU prepolymers and 4,4′-methylene- bis-(2-chloroaniline) (MOCA) as chain extender. The prepolymer was synthesized from poly(hydroxypivalyl hydroxypivalate succinate) (PHPS) or polypropylene glycol 2000 (PPG-2000) with 2,4-toluene diisocyanate (TDI-100), respectively. The structure, morphology, and dynamic and static mechanical properties were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning tunneling microscopy (STM), dynamic mechanical thermal analysis (DMA), and tensile testing machine, respectively. The results indicated that the mass ratios of polyester prepolymer (PESP) and polyether prepolymer (PETP) (mPESP/mPETP ratio) had significantly affected the dynamic mechanical properties of the PUs. When the mPESP/mPETP ratio was 40/60 and 45/55, and PUs had the temperature range (ΔT) higher than 60°C for efficient loss factor (tanδ>0.4) in the DMA curve with bimodal. The phase diagrams of STM indicated that more complex combination of hard and soft segments existed in the PUs, and the segments of PESP and PETP formed irregular block structures. Furthermore, the mechanical properties of PUs were of higher value. It is believed that PUs may be used as potential damping materials.