New poly (urethane-methacrylate)s obtained by adjusting the structure of the polyols moieties: synthesis, transparent, thermal and mechanical properties

A series of novel cross-linked poly (urethane-methacrylate)s (PUAs) were synthesized in a three-step process: Four kinds of low number average molecular weight aromatic polyesters (PEs) with terminal hydroxyl groups were obtained by phthalic anhydride (PA) reacted with 1,2-propanediol (PDO), 1,4-butanediol (BDO), 1,6-hexanediol (HDO), and diethylene glycol (DEG), respectively. Then, a series of urethane-methacrylate macromonomers(UMAs), which have double bonds at the end of the chain, were prepared from isophorone diisocyanate (IPDI), the PEs obtained in first step, poly(ethylene glycol) 600 (PEG600) and -hydroxyethyl methacrylate(HEMA). Dibutytin dilaurate (DBTL) was used as catalyst. Finally, a series of thermosetting PUAs were synthesized by the polymerization of novel functional UMAs using 2,2'-azobis(isobutyronitrile) (AIBN) as catalyst. The compositions of the PEs and UMAs were determined by H-1-NMR and fourier transform infrared (FT-IR). The properties of PUAs were measured by dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), wide-angle X-ray diffraction (WAXD), water uptake and optical properties testing, and mechanical performance measurements. The results revealed that the mechanical and degradation properties of PUAs were influenced by the kinds of PE or polyether polyols in the PUAs remarkably. The obtained PUAs present the good thermal and mechanical properties, low water uptake (below 1%) and high transparence (above 90%). The diversity of properties suggests that these PUAs can be used in a wide range of excellent optical polymer applications.