摘要
多面体低聚倍半硅氧烷(POSS)具有中空刚性的笼型或半笼型结构,它作为一种新型的有机-无机杂化纳米粒子,不仅综合了无机组分和有机组分的优点,还具有两者协同效应产生的新性能,成为分子结构设计中最具潜力的选择。当POSS以分子水平或纳米级聚集体较好地分散于聚合物基体中时,能有效提高材料的热性能、力学性能、磁性能、声学性能、表面性能等,使其在生物医学、催化剂、光学材料和介电材料等领域得到快速发展。POSS的制备方法对POSS/聚合物纳米复合材料的结构性能影响巨大。早期POSS/聚合物纳米复合材料的合成技术不成熟,主要以物理法为主。该法制备的复合材料存在纳米粒子分散不均匀、易团聚的问题,从而影响材料的性能。近年来,研究者不仅关注POSS的结构对复合材料性质的影响,还在不断创新与研究合成技术。随着对POSS结构中Si原子上取代基和高分子链精确控制的实现,化学法制备POSS/聚合物纳米复合材料技术取得了突飞猛进的发展,大大提高了POSS与聚合物基体的相容性。研究者通过不同的化学法已经能够获得具有明确化学结构及各异官能基团的POSS/聚合物纳米复合材料,采用核磁共振氢谱、飞行时间质谱、硅谱、傅里叶红外光谱、广角X射线衍射等多种手段对其结构进行表征;同时还能将POSS以主链、侧链或端基的形式引入聚合物体系中,形成不同拓扑结构的POSS/聚合物纳米复合材料,如接枝型结构、串珠型结构或星型结构等。化学法有利于充分发挥POSS的优异性能,大幅提高POSS/聚合物纳米复合材料的合成效率,为进一步探究POSS/聚合物结构与功能复合材料之间的关系提供了理论基础。本文对POSS的分子结构、性能及POSS/聚合物纳米复合材料结构、制备方法等进行了综述,重点介绍了POSS/聚合物纳米复合材料的制备方法,其中包括共混法、原子转移自由基聚合法、乳液聚合法、点击化学法、静电纺丝法等。针对POSS/聚合物纳米复合材料进一步的发展方向,笔者认为如何确保POSS在不同聚合物基体中的良好分散性仍然是首要解决的问题;采用更多的表征手段获得复合材料的相关信息,探究POSS上取代基反应程度与复合材料性能之间的关系,对于更有效地发挥复合材料的性能具有重要的意义。
Polyhedral oligomeric silsesquioxane(POSS)with a hollow rigid cage or semi cage structure is a new type of organic-inorganic hybrid nano-particles,which not only simultaneously combine the merits of inorganic and organic composition,but also obtains new properties by virtue of the synergistic effects,making it become the most potential choice in molecular structure design.When POSS is well dispersed in polymer matrix at molecular level or nano-scale aggregates,it can effectively improve the thermal properties,mechanical properties,magnetic properties,acoustic properties,surface properties and so on,therefore,POSS has developed rapidly in the field of biomedicine,catalyst,optical materials and dielectric materials.The preparation methods of POSS have vital impact on the structural properties of POSS/polymer nanocomposites.The early synthesis techno-logy of POSS/polymer nanocomposites mainly focused on the physical method which was immature.However,the nanoparticles in the compo-sites prepared by this method disperse unevenly,and are agglomeration-prone,which seriously affect the performances of the materials.Recently,researchers have paid close attention to the influence of structure on the properties of composite materials,in addition,they also have devoted much efforts on continuous innovation and research on synthetic technology.The technology of preparing the POSS/polymer nanocomposites via chemical method has made great progress with the precise control of the substituents and polymer chains on the Si atom in the POSS structure,significantly improving the compatibility between the POSS and the polymer matrix.Researchers have been capable of obtaining POSS/polymer nanocomposites with defined chemical structures and various functional groups through disparate chemical methods,and the structures are characterized by nuclear magnetic resonance hydrogen spectrum,time of flight mass spectrometry,silicon spectroscopy,fourier transform infrared spectroscopy,and wide angle X-ray diffraction.At the same time,POSS can be assembled into the polymer system in the form of main chain,side chain or end group to form POSS/polymer nanocomposites with diffe-rent topological structures such as graft structure,bead type structure or star type structure.The chemical method is benificial to give full play to the superior performance of POSS,greatly improve the synthesis efficiency of POSS/polymer nanocomposites,and provides a theoretical basis for further exploring the relationship between the structure of POSS/polymer and functional composite.In this paper,the molecular structure and properties of POSS and the structure and preparation methods of POSS/polymer nanocomposites were reviewed respectively.In which the preparation methods of POSS/polymer nanocomposites including blending method,atomic transfer free radical polymerization method,emulsion polymerization method,point strike chemistry method,electrospinning method were highlighted.Finally,the author proposes the further development direction of POSS/polymer nanocomposites,who believes that ensuring the good dispersion of POSS in diverse polymer matrix is still the primary problem,more characterization methods should be employed to acquire the related information of composite materials,and seek out the relationship between the degree of reaction of substituents and the properties of composite materials,which is of great significance for achieving potential the properties of composite materials.
作者
高党鸽
王平平
吕斌
马建中
GAO Dangge;WANG Pingping;LYU Bin;MA Jianzhong(College of Bioresources Chemical and Materials Engineering,Shaanxi University of Science&Technology,Xi’an 710021;National Demonstration Center for Experimental Light Chemistry Engineering Education(Shaanxi University of Science&Technology),Xi’an 710021)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2019年第3期550-557,共8页
Materials Reports
基金
国家自然科学基金面上项目(21878182)
轻化工程国家级实验教学示范中心(陕西科技大学)开放课题(2018QGSJ02-14)
陕西省重点研发计划项目(2018GY-068)~~
