溶剂型丙烯酸酯压敏胶的流变性能研究.pdf

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材料工程/2012年10期
溶剂型丙烯酸酯压敏胶的
流变性能研究
The Rheology of Solvent Based Polyacrylate
Pressure Sensitive Adhesives
张晓雯,丁宇婷,张官理,厉蕾,颜悦
(北京航空材料研究院,北京10095)
ZHANG Xiao-wen, DING Yu-ting, ZHANG Guan-li, LI Lei, YAN Yue
(Beijing Institute of Aeronautical Materials, Beijing 100095, China)
摘要:针对分子量不同的溶剂型丙烯酸酯共聚物压敏胶的流变性能进行研究,通过频率扫描、振幅扫描两种不同模式进
行涴变性能测试,并对其蠕变性能进行了测试,通过测试,分析了分子量对流变性能的影响。结果表明,分子量增大,区
分频率值(f)变小,零剪切貓度(か)变大,样品的弹性变好;在振幅扫描模式下,随着分子量变大,样品的线性黏弹区域
变大,弹性模量(G)与黏性模量(G")均变大,但弹性模量增大的幅度大于黏性模量,因此,随着分子量变大,样品逐渐从
G'G",样品由黏弹性液体流变行为逐渐向黏弹性固体流变行为转变;蠕变测试说明分子量增
大,有利于改善样品的抗剪切变形能力与端变回复能力,端变回复时间也随之变大。
关键词;丙烯酸酯;压敏胶;流变
中图分类号:O623.624文献标识码:A文章编号:1001-4381(2012)10-0030-05
Abstract: The rheology of solvent based polyacrylate pressure sensitive adhesives (PSA) with differ
ent molecular weight was studied, the rheological parameters were decided in frequency sweep, ampli
tude sweep patterns respectively, creep recovery properties were also studied, in this way, as the mo
lecular weights of the PSAS were changed, the elasticity and the viscosity of the PSAS were systemati
cally analysed, which were two of the most important properties of the solvent based polyacrylate
PSAS. The results demonstrated that the cross-over frequency(f*) decreased while the zero shear
riscosity(o) and the elasticity increased as the molecular weight of the PSA increased; in amplitude
sweep pattern, the linear viscoelastic range (I VE) and the elastic modules(G and the viscous mod
ules (G) also increased as the molecular weight increased, however, the increment of the elastic mod
ules was greater than that of the viscous modules, accordingly, it showed that GG-G and G>G"in the end as the molecular weights of the PSAS were increased, which meant that
the rheological behaviours of the PSAS were shifted from viscoelastic fluid to viscoelastic solid; via the
creep recovery test, it proved that the increase of the molecular weight plays an important role in the
improvement of the creep recovery properties of the PSA, and the creep recovery time was obviousl
elongated
Key words: polyacrylate; pressure sensitive adhesive; Theology
丙烯酸酯类压敏胶是目前发展最为迅速、应用前特性,压敏胶的流变性能不仅能控制黏性,同时能够决
景最为广阔的一类胶黏剂。溶剂型丙烯酸酯压敏胶具定压敏胶使用的持久性。压敏胶的黏弹特性随着温度
有平均相对分子量较低,润湿性好,初黏力大,干燥速及剪切频率的变化表现出不同的固体以及液体行为,
度快,耐水性好等诸多优点,至今已被广泛用于制作医因此表现出不同的黏结性能。压敏胶的黏弹性行为可
用胶带、压敏标签、BOPP包装胶带、文具胶带、双面胶以用弹性模量(G),黏性模量(G")以及柔性模量(J)
带、防爆胶带等-。
等黏弹性参数来表征。压敏胶的黏结性能与黏弹性存
流变学是研究物质流动与变形的科学,研究的主在着密不可分的关联。黏合或黏性是一个低速过程,
要对象就是物质的黏弹性们。压敏胶具有典型的黏弹这时胶黏剂表现出足够的液体行为,有良好的流动变