Structure-Gas Barrier Property Relationship in a Novel Polyimide Containing Naphthalene and Amide Groups: Evaluation by Experiments and Simulations.

Yi Zeng,Jinghua Tan,Jie Huang,Junjie Liu,Ao Tang,Hong Chen,Chengliang Chen,Yiwu Liu

doi:10.3390/ma14061402

Yi Zeng, Jinghua Tan + Show 6 more

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https://doi.org/10.3390/ma14061402

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Abstract

In order to meet the increasingly stringent requirements for heat resistance and barrier properties in the packaging and electronic device encapsulation field. A high-barrier polyimide (NAPPI) contains naphthalene ring and amide group was prepared by polymerization of a novel diamine (NAPDA) and pyromellitic dianhydride. The structure and properties of diamine monomers and polymers were characterized. Results show that the NAPPI exhibits superior barrier properties with extremely low water vapor and oxygen transmission rate values of 0.14 g·m−2·day−1 and 0.04 cm3·m−2·day−1, respectively. In addition, the NAPPI presents outstanding mechanical properties and thermal stability as well. This article attempts to explore the relationship between NAPPI structure and barrier properties by combining experiment and simulation. Studies on positron annihilation lifetime spectroscopy, Wide angle X-ray diffractograms and molecular dynamics simulations prove that the NAPPI has smaller interplanar spacing and higher chain regularity. In addition, the strong chain rigidity and interchain cohesion of NAPPI due to the presence of the rigid naphthalene ring and a large number of hydrogen bond interactions formed by amide groups result in compact chain packing and smaller free volume, which reduces the solubility and diffusibility of small molecules in the matrix. In general, the simulation results are consistent with the experimental results, which are important for understanding the barrier mechanism of NAPPI.

Highlights

Polymers which provide barriers toward gases play a key role in packaging application and electronic encapsulation due to their lightweight, low cost, flexibility, and processing features [1,2,3,4,5]
Compared with traditional barrier materials such as glass and metals or ceramics, common polymer barrier materials have relatively high permeability and comparatively low thermal resistance, this limits their application in the encapsulation of novel electronic devices such as flexible organic light emitting diodes (OLEDs) and flexible solar cells [6,7,8,9,10]
Referring to to the the relevant relevant literature literature and and based based on on the the previous previous experience, experience, this this study study aimed at a kind of polyimide which containing amide groups and naphthalene rings as aimed at a kind of polyimide which containing amide groups and naphthalene rings as the the object

Summary

Introduction

Polymers which provide barriers toward gases play a key role in packaging application and electronic encapsulation due to their lightweight, low cost, flexibility, and processing features [1,2,3,4,5]. Studies have shown that the significant improvement in barrier performance may be caused by the subtle structural changes in the polymer backbone [16,17,18]. This provides the possibility to synthesize a novel polymer material with high heat resistance and high barrier properties

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