氮化硼表面改性及其对PVC膜耐碱性能的影响

Surface modification of boron nitride and its effect on alkali resistance property of polyvinyl chloride membranes

为了利用六方氮化硼(h-BN)二维的层层堆叠结构延缓聚氯乙烯(PVC)膜在碱性介质中的腐蚀速度,采用异丙基三(二辛基焦磷酸酰氧基)钛酸酯(NZD-201)对h-BN进行化学改性,得到Mh-BN,并通过物理共混的方法将Mh-BN添加到PVC基体中,制备Mh-BN/PVC膜。通过失重率、物理尺寸变化、力学、色差、表观形貌等对该膜的耐碱性能进行分析。结果表明:相比于h-BN,Mh-BN表面能从59.69mJ/m^(2)下降至52.64mJ/m^(2),与PVC膜极性更加接近,相容性改善;接枝NZD-201可提升其与PVC基体的界面结合力;当Mh-BN的质量分数达到2.0%时,其在PVC膜中堆叠形成较为致密的“迷宫”结构,可有效阻隔碱性介质对PVC膜材的腐蚀,Mh-BN/PVC膜的失重率从13.33%下降至8.16%,拉伸应变保持率从62.11%提高至93.66%。耐腐蚀性能的提升对于扩展传统PVC膜的应用领域具有重要意义,该方法制备简单,结构可控,为耐腐蚀PVC膜的制备提供了理论参考。

In order to delay the corrosion rate of polyvinyl chloride(PVC)membranes in alkaline medium by using two-dimensional layer-by-layer stacked structure of hexagonal boron nitride(h-BN),h-BN was chemically modified by isopropyl tri(dioctyl pyrophosphate acyloxy)titanate(NZD-201)to obtain Mh-BN.Meanwhile,modified h-BN(Mh-BN)was added to PVC matrix by physical blending method to prepare Mh-BN/PVC membranes.And the alkali resistance property of the membranes was systematically analyzed through weight loss rate,physical size change,mechanics,chromatic aberration,and apparent morphology,etc.the results showed that,compared with h-BN,the surface energy of Mh-BN decreased from 59.69mJ/m^(2) to 52.64 mJ/m^(2),which is closer to the polarity of the PVC membranes,and the compatibility was improved.At the same time,the grafting of NZD-201could improve the interface bonding force between Mh-BN and the PVC matrix.When the mass fraction of Mh-BN reached 2.0%,it was stacked in the PVC membranes to form a relatively dense"labyrinth"structure,which can effectively block the corrosion of PVC membranes by the alkaline medium.The weight loss rate of Mh-BN/PVC membranes decreased from 13.33%to 8.16%,and the tensile strain retention rate increased from 62.11%to 93.66%.The improvement of corrosion resistance property is of great significance for expanding the application fields of traditional PVC membranes.This method is simple,and the structure is controlled.This paper provides theoretical guidance for the preparation of corrosion-resistant PVC membranes.