Work

Effect of CN9021 crosslinker content on mechanical and actuation properties of acrylic dielectric elastomers and their constitutive modeling

Year: 2025

Type: article

Abstract: Dielectric elastomers (DEs) are promising electroactive polymers for soft robotics and artificial muscles due to their large strain capability (>100%), high energy density, and fast response. However, commercial VHB materials require substantial pre-stretching (300-500%) and exhibit high viscoelastic losses, significantly limiting practical applications. This study systematically investigates the influence of high molecular weight polyurethane diacrylate crosslinker CN9021 content (30-100 wt%) on the structure-property relationships of acrylate-based DE materials. Through UV-induced photopolymerization, we fabricated a series of DE films with tunable crosslinking density from 1.42×10⁻⁵ to 5.12×10⁻⁵ mol/cm³. Young's modulus was modulated over a 7.4-fold range (0.05-0.37 MPa), with medium crosslinking density sample UB55 exhibiting energy dissipation of only 9.69% versus 29.82% for VHB4910. Comparative evaluation of five hyperelastic constitutive models revealed that the third-order Ogden model most accurately describes the nonlinear mechanical behavior of this material system (R²>0.9999, RMSE<0.0004 MPa). All developed materials demonstrated superior dielectric constants (5.8-6.4) compared to VHB4910 (4.7) while maintaining low dielectric losses (<0.08). A dual-optimization strategy was successfully implemented: medium crosslinking density UB55 achieved 198% area strain at 7.5 kV under pre-stretch with 1.76 times higher dynamic amplitude than VHB4910 at 1 Hz; high crosslinking density UB82 enabled 15.6% area strain at 6.5 kV without pre-stretching. Both materials maintained approximately 5 times higher dynamic amplitude than VHB4910 at 30 Hz, confirming excellent broadband frequency response. This work provides comprehensive experimental data and validated theoretical models for rational design of high-performance DE materials tailored to specific operational requirements.

Source: Polymer Testing

DOI: 10.1016/j.polymertesting.2025.109083

Authors: Qinqin Wang, Changgeng Shuai, Xue Yang, Xingying Zhang, Weibin Wu, Gang Lu

Institutions: Naval University of Engineering, Wuhan Institute of Technology

Language: English

Topic: Dielectric materials and actuators

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,370

Funders: National Natural Science Foundation of China, Natural Science Foundation of Hubei Province, Wuhan Institute of Technology