Design and synthesis of isosorbide‐based copolycarbonates with high transparency and low hygroscopicity for optical applications

Abstract

Poly(isosorbide carbonate) (PIC) is an example of the shift from fossil to bio‐based feedstocks in polymeric materials. However, the naturally high hygroscopicity of isosorbide may lead to the bad dimensional stability of its polymers, limiting its application. This work aims to develop a series of isosorbide‐based copolycarbonates by introducing hydrophobic groups, such as alkane chains and aromatic rings, into the polymer backbone via one‐pot melt polycondensation. As expected, the molecular structure and steric hindrance of the comonomer have a remarkable effect on the water absorption of the copolycarbonates. Among the comonomers, tricyclo[5.2.1.0(2,6)]decanedimethanol with an alkane skeleton bridge effectively reduces the saturation water absorption by 61% compared to PIC. The water absorption mechanism and kinetics of the copolycarbonates are investigated. Moreover, the incorporation of comonomers in PIC not only exhibits stronger hydrophobicity, but also significantly improves its optical properties. Copolycarbonates obtained have a light transmittance of 92% and a refractive index of 1.5394, which are higher than those of PIC, along with better thermal stability, flexibility, and lower glass transition temperature. This work provides a new strategy for the design of isosorbide‐based polycarbonates for use in optics.

Polarization Analysis and Humidity Dependence of Dielectric Properties of Aromatic and Semialicyclic Polyimides Measured at 10 GHz

“…They have fully amorphous structures with a large F V because of the bulky and bent isosorbide skeleton and polar benzoyl groups . Water uptake is associated with microvoids located near the imide and benzoate moieties. − …”

Synthesis and Properties of Bio-Based Polycarbonates Containing Silicone Blocks

“…Different types of silicone have varying effects on the hydrophobic performance of copolymers. For the a-PDMS system, p-PDMS, containing a steric hindrance phenyl ring structure, acts as a shield, protecting the internal hydrophilic segments from the influence of external humid environments, resulting in higher water contact angles for its copolymer films [39]. When the p-PDMS content is 3.8 wt%, the water contact angle is 104.6 • .…”

Mechanism Study on Synthesis of Biobased Polycarbonate from Diphenyl Carbonate and Isosorbide with Metal-Free Catalysts by Identifying Reactivity of endo-OH and exo-OH

“…Poly­(isosorbide carbonate) (PIC), an engineering thermoplastic derived from biobased sources, boasts high impact strength and excellent transparency, finding applications in biomedicine, electronics, and food packaging. − Traditionally, the preparation of high-molecular-weight PIC involves the use of metal catalysts to activate the less reactive endo -OH in the presence of strong electrophilic metal ions. , However, residual metal catalysts pose challenges such as side reactions, undesired product discoloration, and environmental concerns. − Efforts to increase the transesterification efficiency under metal-free conditions include hydroxyl substitution, endo -OH isomerization, and metal-free catalyst design. ,− Among these methods, optimizing the catalytic system emerges as the most effective approach, activating the reactivity of endo -OH and exo -OH without additional process steps . Consequently, it is highly desirable to develop an environmentally friendly catalyst with high performance toward the synthesis of polycarbonate derived from the ISB.…”