Center of Excellence Geopolymer and Green Technology (CEGeoGTech), School of Materials Engineering, University Malaysia Perlis, 02600, Perlis, Malaysia.
Center of Excellence Geopolymer and Green Technology (CEGeoGTech), School of Materials Engineering, University Malaysia Perlis, 02600, Perlis, Malaysia.
Mater Sci Eng C Mater Biol Appl. 2017 May 1;74:194-206. doi: 10.1016/j.msec.2016.11.137. Epub 2016 Dec 6.
Polymer-clay based nanocomposites are among the attractive materials to be applied for various applications, including biomedical. The incorporation of the nano sized clay (nanoclay) into polymer matrices can result in their remarkable improvement in mechanical, thermal and barrier properties as long as the nanofillers are well exfoliated and dispersed throughout the matrix. In this work, exfoliation strategy through pre-dispersing process of the organically modified montmorillonite (organo-MMT) nanofiller was done to obtain ethyl vinyl acetate (EVA) nanocomposite with improved flexibility, toughness, thermal stability and biostability. Our results indicated that the degree of organo-MMT exfoliation affects its cytotoxicity level and the properties of the resulting EVA nanocomposite. The pre-dispersed organo-MMT by ultrasonication in water possesses higher degree of exfoliation as compared to its origin condition and significantly performed reduced cytotoxicity level. Beneficially, this nanofiller also enhanced the EVA flexibility, thermal stability and biostability upon the in vitro exposure. We postulated that these were due to plasticizing effect and enhanced EVA-nanofiller interactions contributing to more stable chemical bonds in the main copolymer chains. Improvement in copolymer flexibility is beneficial for close contact with human soft tissue, while enhancement in toughness and biostability is crucial to extend its life expectancy as insulation material for implantable device.
聚合物-粘土基纳米复合材料是一种有吸引力的材料，可应用于各种领域，包括生物医学。将纳米尺寸的粘土（纳米粘土）掺入聚合物基质中，可以显著提高其机械、热和阻隔性能，只要纳米填料得到充分的剥离和分散即可。在这项工作中，通过预先分散有机改性蒙脱石（有机蒙脱土）纳米填料的方法进行剥离策略，以获得具有改善的柔韧性、韧性、热稳定性和生物稳定性的乙烯-醋酸乙烯酯（EVA）纳米复合材料。我们的结果表明，有机蒙脱土的剥离程度影响其细胞毒性水平和所得 EVA 纳米复合材料的性能。与原始状态相比，通过超声分散在水中预先分散的有机蒙脱土具有更高的剥离程度，并且显著降低了细胞毒性水平。有益的是，这种纳米填料还增强了 EVA 的柔韧性、热稳定性和生物稳定性，在体外暴露时也是如此。我们假设，这是由于增塑作用和增强的 EVA-纳米填料相互作用，有助于主共聚物链中更稳定的化学键。共聚物柔韧性的提高有利于与人体软组织的紧密接触，而韧性和生物稳定性的提高对于延长其作为植入装置绝缘材料的预期寿命至关重要。
