Polyester-Polysiloxane Hyperbranched Block Polymers for Transparent Flexible Materials.

Haoyuan Bao,Xilin Hua,Yufei Wu,Guoqiao Lai,Jiangling Liu,Xiongfa Yang

doi:10.1021/acsomega.0c04460

Abstract

Highly transparent flexible silicone elastomers are useful for certain stretchable electronics and various types of smart devices. Polyester–polysiloxane hyperbranched block copolymers are synthesized by ring-opening polymerization of octamethylcyclotetrasiloxane initiated by macromolecular lithium alkoxide. Treatment of these copolymers with tetraethoxysilane and dibutylin dilaurate at room temperature gives the corresponding transparent elastic materials. The transparency of the materials can reach 90% (700–800 nm), and the starting thermal decomposition temperatures of the materials are higher than 330 °C. Very interestingly, though the highest tensile strength of the material prepared is about 0.48 MPa, the elongation at break can reach 778–815%. The results will inspire us to develop highly transparent flexible silicone materials by designing copolymers of silicone materials and hyperbranched polymers.

Highlights

Transparency of polymer materials is significantly important in some fields such as displays,[1] packaging,[2] and flexibile optoelectronic devices.[3−5] As an important class of polymer materials with high transparency, silicone elastomers with high transmittance are essential for stretchable electronics due to their good flexibility, excellent thermal stability, low glasstransition temperature, and good electrical insulation properties.[2,6−9] because of poor mechanical performances, pure silicone elastomers are only sporadically used in device applications.[10,11]
The polyester−polysiloxane hyperbranched block polymers were synthesized by ringopening polymerization of D4 initiated by macromolecular lithium alkoxide prepared from hyperbranched aliphatic polyester (HBPE)
The Tm of HBPE-bPDMS samples may be attributed to the high molecular weight of the PDMS units in the products obtained, which is similar to the results reported by Rong.[30]

Summary

Introduction

Transparency of polymer materials is significantly important in some fields such as displays,[1] packaging,[2] and flexibile optoelectronic devices.[3−5] As an important class of polymer materials with high transparency, silicone elastomers with high transmittance are essential for stretchable electronics due to their good flexibility, excellent thermal stability, low glasstransition temperature, and good electrical insulation properties.[2,6−9] because of poor mechanical performances, pure silicone elastomers are only sporadically used in device applications.[10,11] Incorporation of various inorganic fillers such as nano-SiO2,10,12 carbon nanotubes,[13] nano-Al2O3,14 and clay[15] into polysiloxane matrices has been shown to improve the mechanical properties but at the expense of lower transparency. UV-cured polyether-modified polysiloxane polyurethane acrylate has tensile strength that can reach 2.0 ± 0.3 to 19.8 ± 2.2

Methods

Results

Conclusion