AROMATIC BUT HYDROPHILIC POLYUREAS DERIVED FROM BIO-BASED 4-AMINOCINNAMIC ACID PHOTODIMER

摘要

We have synthesized the aromatic polyureas derived from 4-aminocinnamic acid photodimer which can be regarded as bio-based aromatic diamines. The aromatic biodiamines smoothly reacted with aromatic isocyanates around 60 ℃ for 24 hrs to produce polyureas (Mw ranging 1.81×10~5-2.41 × 10~5 g/mol). The polyureas were easily soluble in polar aprotic solvent such as DMF, NMP, DMAc and DMSO at room temperature and formed the films from DMAc solution at 70℃. The polyureas have the good thermal degradation temperature, T_(10) ＞ 290 ℃ and optical transparency ＞ 85% at λ_(450nm). However the mechanical property of the polyurea films should be improved. Then we tried to reinforce the polyureas by metal salts to improve the mechanical property thought the hydrogen bond between the urea group/ the carboxylic acid group or metal cation. Results are summarized in Table 1 where one can see that Tensile moduli of the polymer film after reinforced reached to 1.8 GPa and tensile strength to 43 MPa, almost same with those of PBT plastics. The researchers were financially supported by ALCA project (5100270) of JST.