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首页> 外文期刊>Journal of Applied Polymer Science >Controlled destruction of residual crosslinker in a silicone elastomer for drug delivery
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Controlled destruction of residual crosslinker in a silicone elastomer for drug delivery

机译：可控地破坏有机硅弹性体中残留的交联剂，以进行药物输送

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In drug delivery systems that use silicone elastomers as a diffusion matrix for the active drug, it is common to crosslink the material by the hydrosilylation reaction. In this platinum-catalyzed reaction, vinyl groups on a polymer add to the methyl siloxane hydride (MHS) groups on a low molecular mass crosslinker. With an excess of crosslinker, a fast curing is achieved and a fully crosslinked material is formed. Unreacted MHS groups were shown to remain in the elastomer after curing because of the excess crosslinker. In this work, a simple procedure was developed to eliminate the unreacted MHS groups from the final product. We found that storage of the product at +40degrees and 75% relative humidity for a few weeks will effectively destroy the residual MHS groups in the elastomer. The effects of varying levels of humidity, oxygen, and temperature on this postcuring procedure were studied. The amount of MHS groups was measured with NMR and IR spectroscopy. We also found that the hardness of the material increased by approximately 25% as a consequence of this postcuring treatment. This increase is probably due to a secondary crosslinking reaction between MHS and silanol groups. Heat treatment at higher temperatures led to an even further increase in the hardness and compression modulus. Because no MHS groups remained in the elastomer when this heat treatment was started, it is apparent that another secondary crosslinking reaction is occurring, probably silanol condensation. (C) 2002 Wiley Periodicals, Inc. [References: 6]
机译：在使用硅氧烷弹性体作为活性药物的扩散基质的药物递送系统中，通常通过氢化硅烷化反应使材料交联。在该铂催化的反应中，聚合物上的乙烯基加到低分子量交联剂上的甲基硅氧烷氢化物（MHS）基团上。使用过量的交联剂，可以实现快速固化并形成完全交联的材料。固化后，由于过量的交联剂，未反应的MHS基团保留在弹性体中。在这项工作中，开发了一种简单的程序以从最终产品中消除未反应的MHS组。我们发现，该产品在+40度和75％的相对湿度下存储数周将有效破坏弹性体中的残留MHS基团。研究了湿度，氧气和温度的变化对此后固化过程的影响。 MHS基团的量通过NMR和IR光谱法测量。我们还发现，由于这种后固化处理，材料的硬度增加了约25％。这种增加可能是由于MHS和硅烷醇基团之间的二次交联反应。在较高温度下的热处理导致硬度和压缩模量甚至进一步增加。由于开始加热处理时弹性体中没有MHS基团，因此显然发生了另一次交联反应，可能是硅烷醇缩合。 （C）2002 Wiley Periodicals，Inc. [参考：6]

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