MBTA is a sulfur-rich acrylic monomer engineered for high-refractive-index (RI ≥ 1.62 @ 589 nm, 25 °C) UV/LED-curable optical systems.
The benzothiazole–thio-ether conjugation delivers n<sub><sup> ≈ 1.622 while maintaining Abbe number ≈ 26, ideal for thin-film microlenses, AR/VR pancake optics, waveguide claddings, and high-n encapsulants.
Single acrylate functionality provides low shrinkage (< 2 %) and fast surface-through cure with standard Type I photoinitiators (TPO, 1173).
Key Optical & Physical Data:
Refractive index (n<sub><sup>): 1.620 – 1.625
Abbe number (ν<sub>): 26 ± 1
Density: 1.31 g cm⁻³ (20 °C)
Viscosity (25 °C): 85 – 95 mPa·s (easy pumping & coating)
Volume shrinkage on cure: < 2 % (density dilatometry)
**Glass-transition temperature (DSC, 2 % TPO)****: 138 °C
2-(2-Benzothiazolylthio)ethyl acrylate
Synonyms: MBTA
CAS No.: 39667-72-6
Purity: ≥ 98 % (GC)
Refractive Index：1.622
Molecular Formula: C₁₂H₁₁NO₂S₂
Molecular Weight: 265.35 g mol⁻¹
Appearance: Light-yellow transparent liquid; almost odourless
