Phosphorus- and Sulfur-Containing High-Refractive-Index Polymers with High Tg and Transparency Derived from a Bio-Based Aldehyde
journal contributionposted on 02.01.2020, 17:34 by Linxuan Fang, Jing Sun, Xiaoyao Chen, Yangqing Tao, Junfeng Zhou, Caiyun Wang, Qiang Fang
Two flexible and colorless polymers are synthesized based on a phosphorus-containing derivative of a bio-based aromatic aldehyde (4-hydroxybenzaldehyde) by a thiol-ene reaction. Thanks to the high polarizability of phosphorus and sulfur atoms, two polymers display refractive index (n) values of 1.721 and 1.698 at 546 nm, respectively. These data are much higher than those of polyphosphonates (below 1.65) and are comparable to those of polyphosphazenes with undesirable halogens (1.664–1.755). Moreover, both the polymers (TVP-TH1 and TVP-TH2) exhibit a transmittance of above 88% in the wavelength range from 550 to 2000 nm and a transmittance of about 0% in the UV region, indicating their potential application as transparent coatings for hindering the ultraviolet ray and infrared transmitting materials. In particular, these phosphorous-sulfide polymers display good thermostability with a glass transition temperature (Tg) of above 130 °C and 5% weight loss temperature (T5d) of over 310 °C. These results imply that new phosphorous-sulfide polymers are very suitable as encapsulation resins for light-emitting diodes (LEDs) and optical materials and as antireflective coatings and microlenses for the image sensors of complementary metal oxide semiconductors (CMOSs).
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thiol-ene reaction2000 nmphosphorous-sulfide polymers displayCMOSHigh T gmaterialTVP-TH 2TVP-TH 1Transparency Derivedsulfur atomsUV regionSulfur-Containing High-Refractive-Index Polymersencapsulation resinsT gtransmittance546 nmglass transition temperatureimage sensorsmetal oxide semiconductorslight-emitting diodesLEDpolymers displayantireflective coatingsphosphorous-sulfide polymersT 5Bio-Based Aldehydewavelength range