ABSTRACT

The importance of alumina and titania is exceptionally high for modern life since they appear in all materials science fields and perform essential tasks without which modern life would not be possible. Every day, the window of application of these oxides expands, including polymer science and technology. Alumina and titania as nanofillers are explored in the present work, aiming to expand the window of application of these oxides as a secondary phase in extruded PVDF composites. Unexpected findings lead to the belief that PVDF induces an unknown phase transition/oxidation in γ-alumina and anatase, which causes their composites to be dark and present unusual thermal behavior; T_max decreased 75 and 61°C upon the incorporation of anatase and γ-alumina to PVDF matrix, respectively. All the titania and alumina composites possess lower mechanical properties and degradation temperatures than pure PVDF; however, the crystallinity degree is 3% higher for rutile, which could have positive application in membranes and pipes with selective permeability. The formation of the transformation mentioned above in γ-alumina and anatase decreased the viscosity of the polymer by 6 and 24% respectively, which is closely related to the unexpected thermal behavior of those composites and possess a new research subject about the causes of this transformation induced by polymer and its possibility for future applications.

摘要

氧化铝和二氧化钛对现代生活的重要性异常重要，因为它们出现在所有材料科学领域并执行重要的任务，否则将无法实现现代生活。每天，这些氧化物的应用范围不断扩大，包括聚合物科学和技术。在本工作中探索了氧化铝和二氧化钛作为纳米填料，旨在扩大这些氧化物作为挤出PVDF复合材料中的第二相的应用范围。出乎意料的发现导致人们相信，PVDF会引起γ-氧化铝和锐钛矿中未知的相变/氧化，从而导致其复合材料变黑并表现出异常的热行为。Ť_最大将锐钛矿和γ-氧化铝掺入PVDF基质后，温度分别降低了75和61°C。所有二氧化钛和氧化铝复合材料的机械性能和降解温度均低于纯PVDF。然而，金红石的结晶度高3％，这可能对具有选择性渗透性的膜和管道有积极的应用。γ-氧化铝和锐钛矿中上述相变的形成分别使聚合物的粘度降低了6％和24％，这与这些复合材料的意外热行为密切相关，并且对该相变的原因有了新的研究课题由聚合物引起的氧化及其未来应用的可能性。