Scholarlink

<p>The nematic-isotropic phase transitions of liquid-crystal elastomers (LCEs) produce large, reversible changes in viscoelasticity, making LCEs attractive for phase-dependent adhesives. However, intrinsic rigidity of mesogens and the high crosslink density of conventional LCE networks suppress immediate tack, preventing true pressure-sensitive adhesion (PSA) and often requiring time- or temperature-assisted wetting. Here, we introduce a simple and robust chain-transfer strategy using commercially available dithiols to regulate the radical polymerization. By tuning the viscoelastic window, the resulting networks exhibit a dramatic reduction in glass-transition temperature from 193 to –11 °C and a four-order-of-magnitude decrease in storage modulus from &gt;1000 to 0.1 MPa. This satisfies the Dahlquist criterion and enables PSA without additives or pretreatment. The modified networks provide exceptional viscoelastic dissipation, with a peak loss factor (tan δ) of 1.85 and a broad damping plateau (tan δ ≈ 0.91) in the nematic phase, reflected in a peel strength of 1.08 N mm⁻¹. Upon heating into the isotropic phase, adhesion drops sharply to 0.004 N mm⁻¹, enabling clean, programmable debonding.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Reversible acrylic pressure-sensitive adhesives based on liquid crystal elastomers enabled by thiol chain transfer agent

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年7月10日

查看全文
  • Lichang Lu,
  • Kailing Lin,
  • Mohand O. Saed

摘要

The nematic-isotropic phase transitions of liquid-crystal elastomers (LCEs) produce large, reversible changes in viscoelasticity, making LCEs attractive for phase-dependent adhesives. However, intrinsic rigidity of mesogens and the high crosslink density of conventional LCE networks suppress immediate tack, preventing true pressure-sensitive adhesion (PSA) and often requiring time- or temperature-assisted wetting. Here, we introduce a simple and robust chain-transfer strategy using commercially available dithiols to regulate the radical polymerization. By tuning the viscoelastic window, the resulting networks exhibit a dramatic reduction in glass-transition temperature from 193 to –11 °C and a four-order-of-magnitude decrease in storage modulus from >1000 to 0.1 MPa. This satisfies the Dahlquist criterion and enables PSA without additives or pretreatment. The modified networks provide exceptional viscoelastic dissipation, with a peak loss factor (tan δ) of 1.85 and a broad damping plateau (tan δ ≈ 0.91) in the nematic phase, reflected in a peel strength of 1.08 N mm⁻¹. Upon heating into the isotropic phase, adhesion drops sharply to 0.004 N mm⁻¹, enabling clean, programmable debonding.