氧化锌纳米棒增强聚酰胺-酰亚胺复合材料的力学性能及协同界面相互作用

Mechanical Properties and Synergistic Interfacial Interactions of ZnO Nanorod-Reinforced Polyamide-Imide Composites.

作者信息

Kesler Dallas, Ariyawansa Bhanuka P, Rathnayake Hemali

机构信息

Nanoscience Department, University of North Carolina Greensboro, Greensboro, NC 27412, USA.

Middle College, University of North Carolina Greensboro, Greensboro, NC 27412, USA.

出版信息

Polymers (Basel). 2023 Mar 19;15(6):1522. doi: 10.3390/polym15061522.

DOI:10.3390/polym15061522

PMID:36987302

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC10055968/

Abstract

Metal oxide nanoparticle -reinforced polymers have received considerable attention due to their favorable mechanical properties compared to neat materials. However, the effect of nanoscale reinforcements of the interface on the composites' mechanical properties has not been investigated in-depth to reach their optimal performance in structural applications. Aiming at revealing the effect of synergistic interfacial interactions on the mechanical properties of polymer composites, using a nanoscale reinforcement, herein, a series of zinc oxide nanorod-reinforced polyamide-imide (PAI)/ZnO) composites were fabricated and their mechanical properties and viscoelastic responses were investigated. The composite prepared by reinforcing them with 5 wt % ZnO nanorods resulted in improved elastic modulus, stiffness, and hardness values by 32%, 14% and 35%, respectively, compared to neat polymer thin films. The viscoelastic dynamics of the composites revealed that there was an 11% increase in elastic wave speed in the composite, containing 5 wt % ZnO nanorods, indicating better response to high impacts. Delayed viscoelastic response decreased by 67% spatially and 51% temporally, with a corresponding decrease in the creep rate, for the 5 wt % ZnO nanorod- containing composite, evidencing its potential applicability in high strength lightweight structures. The improved mechanical properties with respect to the filler concentration evidence strong particle-polymer interfacial interactions, creating "chain-bound" clusters, providing clear reinforcement and polymer chain mobility retardation. However, hypervelocity impact testing revealed that all the composites' films were vulnerable to hypervelocity impact, but the spallation region of the composite films reinforced with 2.5 wt % and 5 wt % ZnO nanorods exhibited a cellular-like matrix with shock-induced voids compared to a rather hardened spallation region with cracks in the neat film.

摘要

与纯材料相比，金属氧化物纳米颗粒增强聚合物因其良好的机械性能而受到广泛关注。然而，纳米级增强剂对复合材料界面的影响及其对复合材料在结构应用中最佳性能的作用尚未得到深入研究。为了揭示协同界面相互作用对聚合物复合材料机械性能的影响，本文采用纳米级增强剂制备了一系列氧化锌纳米棒增强聚酰胺酰亚胺（PAI/ZnO）复合材料，并研究了它们的机械性能和粘弹性响应。与纯聚合物薄膜相比，用5 wt%的氧化锌纳米棒增强制备的复合材料的弹性模量、刚度和硬度值分别提高了32%、14%和35%。复合材料的粘弹性动力学表明，含有5 wt%氧化锌纳米棒的复合材料中的弹性波速提高了11%，表明对高冲击的响应更好。对于含有5 wt%氧化锌纳米棒的复合材料，延迟粘弹性响应在空间上降低了67%，在时间上降低了51%，蠕变速率相应降低，证明了其在高强度轻质结构中的潜在适用性。相对于填料浓度而言，机械性能的改善证明了颗粒与聚合物之间存在强烈的界面相互作用，形成了“链束缚”簇，提供了明显的增强作用并阻碍了聚合物链的移动。然而，超高速冲击试验表明，所有复合材料薄膜都易受超高速冲击，但与纯薄膜中带有裂纹的相当硬化的剥落区域相比，用2.5 wt%和5 wt%氧化锌纳米棒增强的复合材料薄膜的剥落区域呈现出带有冲击诱导孔隙的蜂窝状基体。