Guder Marian, Günther Roman, Bremgartner Katharina, Senn Nicole, Brändli Christof
Laboratory of Adhesives and Polymer Materials, Institute of Materials and Process Engineering, ZHAW Zurich University of Applied Sciences, 8401 Winterthur, Switzerland.
aquatherm GmbH, 57439 Attendorn, Germany.
Polymers (Basel). 2024 Jul 25;16(15):2123. doi: 10.3390/polym16152123.
This study emphasizes the influential role of rheology in decoding the viscoelastic properties of pressure-sensitive adhesives (PSAs) vital to predicting key application features such as shear, tack, and peel, depending on the flow characteristics of PSAs during bonding and debonding processes. By applying the principle of time-temperature superposition (TTS), we extend the scope of our frequency analysis, surpassing the technical constraints of the available apparatus. Our exploration aims to uncover the general correlations between PSAs' viscoelastic properties and their performance in end-use applications. Initially, the adhesive performance and viscoelastic properties of a UV-crosslinkable styrene-butadiene-styrene (SBS) model adhesive prior and subsequent to UV irradiation were examined. The subsequent crosslinking reaction increased cohesive strength and heat resistance, although tack and peel strength observed a substantial decline. We successfully demonstrated these effects by logging the viscoelastic properties, specifically the storage modulus G' at lower frequencies, which mirrors the shear strength at higher temperatures and the shift in the tan δ peak to represent each PSA's tack. These correlations were partially reflected in three commercial UV crosslinkable acrylic PSA products, although the effect of UV irradiation was less distinctive. This study also revealed the challenges in predicting tack and peel strength, which result from a complex interplay of bonding and debonding processes. Our findings reinforce the necessity for more sophisticated analysis techniques and models that can accurately predict the end-use performance of PSAs across different physical structures and chemical compositions. Further research is needed to develop these predictive models, which may reduce the need for labor-intensive testing under real-life conditions.
本研究强调了流变学在解读压敏胶粘剂（PSA）粘弹性特性方面的重要作用，这些特性对于预测诸如剪切、粘性和剥离等关键应用特性至关重要，这取决于PSA在粘结和脱粘过程中的流动特性。通过应用时温叠加原理（TTS），我们扩展了频率分析的范围，超越了现有仪器的技术限制。我们的探索旨在揭示PSA粘弹性特性与其在最终应用中的性能之间的一般相关性。最初，研究了紫外线可交联苯乙烯-丁二烯-苯乙烯（SBS）模型胶粘剂在紫外线照射前后的粘合性能和粘弹性特性。随后的交联反应提高了内聚强度和耐热性，尽管粘性和剥离强度大幅下降。我们通过记录粘弹性特性成功证明了这些影响，特别是在较低频率下的储能模量G'，它反映了较高温度下的剪切强度以及tanδ峰的位移以表示每种PSA的粘性。这些相关性在三种商用紫外线可交联丙烯酸PSA产品中部分得到体现，尽管紫外线照射的影响不太明显。本研究还揭示了预测粘性和剥离强度时面临的挑战，这是由粘结和脱粘过程的复杂相互作用导致的。我们的研究结果强化了需要更复杂的分析技术和模型的必要性，这些技术和模型能够准确预测不同物理结构和化学成分的PSA的最终使用性能。需要进一步研究来开发这些预测模型，这可能会减少在实际条件下进行劳动密集型测试的需求。
