Form-stable benzoxazine-urethane alloys for thermally reversible light scattering materials

eXPRESS Polymer Letters

T. Parnklang¹ 

关键词: polymer blends and alloys;    smart polymers;    polybenzoxazine;    urethane;    thermally reversible light scattering;   

DOI  :  10.3144/expresspolymlett.2019.7

学科分类：生物科学（综合）

来源: eXPRESS Polymer Letters

【 摘 要 】

Thermally reversible light scattering (TRLS) materials based solely on benzoxazine-urethane (BA-a/PU) alloyswere successfully fabricated and demonstrated in this work. The alloys displayed the opaque state below 40 °C. The alloyswere transformed to the transparent state upon exposing to the transition temperature of 60–130 °C, depending on the molecularweights and mass concentrations of urethane prepolymers in the BA-a/PU alloys. The optical state transitions werereversible with small hystereses. BA-a/PU alloys exhibited a good optical contrast with 0%T at the light scattering state andalmost 100%T at the transparent state. The alloys were glassy and form-stable up to 250 °C, due to the synergistic behaviorin the glass transition temperatures. The reaction-induced phase separation effectuated by the incorporation of urethane prepolymerinto thermosetting polybenzoxazine, the sizes and local concentrations of the phase-separated urethane microdomainsin the supporting polybenzoxazine matrix, and the reversible dissolution and demixing of urethane microdomainsand polybenzoxazine phase played crucial roles on TRLS properties of the developed benzoxazine-urethane alloys.

【 授权许可】

CC BY