scholarly journals High-Barrier Polyimide Containing Carbazole Moiety: Synthesis, Gas Barrier Properties, and Molecular Simulations

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2048
Author(s):  
Yiwu Liu ◽  
Ao Tang ◽  
Jinghua Tan ◽  
Xianqing Zhao ◽  
Chengliang Chen ◽  
...  

A high-barrier polyimide (2,7-CPI) was synthesized through the polymerization of pyromellitic dianhydride (PMDA) and a novel diamine (2,7-CDA) containing carbazole moiety. The synthesized diamine and polyimide were fully characterized by elemental analyses, FTIR and NMR. The 2,7-CPI displays very attractive barrier performances, with oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) low to 0.14 cm3·m−2·day−1 and 0.05 g·m−2·day−1, respectively. Meanwhile, 2,7-CPI also exhibits exceptional thermal stability with a glass transition temperature (Tg) of 467 °C, 5% weight-loss temperature (Td5%) of 550 °C under N2 and coefficient of thermal expansion (CTE) of 3.4 ppm/K. The barrier performances of 2,7-CPI are compared with those of a structural analogue (2,7-CPPI) and a typical polyimide (Kapton). Their barrier performances with respect to microstructure were investigated by molecular simulations, wide angle X-ray diffraction (WAXD), and positron annihilation lifetime spectroscopy (PALS). The results show that 2,7-CPI possesses better coplanar structure and more number of intermolecular hydrogen bonds among the three PIs, which result in tight chain packing and thereby high crystallinity, low free volume, and decreased chains mobility. That is, the high crystallinity and low free volume of 2,7-CPI reduce the diffusion and solubility of gases. Meanwhile, the poor chains mobility further decreases the gases diffusion. The reduced diffusion and solubility of gases consequently promote the improvement of barrier properties for 2,7-CPI. The polyimide has a wide application prospect in the field of flexible electronic packaging industries.

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2097
Author(s):  
Qian Wen ◽  
Ao Tang ◽  
Chengliang Chen ◽  
Yiwu Liu ◽  
Chunguang Xiao ◽  
...  

This study designed and synthesised a meta-amide-substituted dianiline monomer (m-DABA) as a stereoisomer of DABA, a previously investigated para-amide-substituted dianiline monomer. This new monomer was polymerised with pyromellitic dianhydride (PMDA) to prepare a polyimide film (m-DABPI) in a process similar to that employed in a previous study. The relationship between the substitution positions on the monomer and the gas barrier properties of the polyimide film was investigated via molecular simulation, wide-angle X-ray diffraction (WXRD), and positron annihilation lifetime spectroscopy (PALS) to gain deeper insights into the gas barrier mechanism. The results showed that compared with the para-substituted DABPI, the m-DABPI exhibited better gas barrier properties, with a water vapour transmission rate (WVTR) and an oxygen transmission rate (OTR) as low as 2.8 g·m−2·d−1 and 3.3 cm3·m−2·d−1, respectively. This was because the meta-linked polyimide molecular chains were more tightly packed, leading to a smaller free volume and lower molecular chain mobility. These properties are not conducive to the permeation of small molecules into the film; thus, the gas barrier properties were improved. The findings have significant implications for the structural design of high-barrier materials and could promote the development of flexible display technology.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1402
Author(s):  
Yi Zeng ◽  
Yiwu Liu ◽  
Jinghua Tan ◽  
Jie Huang ◽  
Junjie Liu ◽  
...  

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.


2015 ◽  
Vol 15 (10) ◽  
pp. 8348-8352 ◽  
Author(s):  
Min Eui Lee ◽  
Hyoung-Joon Jin

Poly(vinyl alcohol) (PVA) composites containing graphene oxide (GO) functionalized with PVA were synthesized via the esterification of the carboxylic groups of GO. The presence of PVA-grafted GO (PVA-g-GO) in the PVA matrix induced strong interactions between the chains of the PVA matrix and allowed the PVA-g-GO to be uniformly dispersed throughout the matrix. The grafting of PVA to GO increased the gas barrier properties of the GO/PVA composites because of the increased compatibility between GO and PVA. The PVA-g-GO/PVA composites were used to coat the surface of poly(ethylene terephthalate) films. These coated films exhibited excellent gas barrier properties; the film containing 0.3 wt% of PVA-g-GO had an oxygen transmission rate (OTR) of 0.025 cc/(m2 · day) and an optical transmittance of 83.8%. As a result, PVA-g-GO/PVA composites that exhibited enhanced gas barrier properties were prepared with a solution mixing method.


Holzforschung ◽  
2013 ◽  
Vol 67 (8) ◽  
pp. 899-905 ◽  
Author(s):  
Eva-Lena Hult ◽  
Klaus Koivu ◽  
Janne Asikkala ◽  
Jarmo Ropponen ◽  
Pauli Wrigstedt ◽  
...  

Abstract Lignin, esterified with palmitic and lauric acid chloride, has been studied for the application as coating on fiber-based packaging material. The aim was to improve the barrier properties against water vapor and oxygen of paperboard. The esterification was followed by Fourier transform infrared spectroscopy, 31P nuclear magnetic resonance spectroscopy, and gel permeation chromatography measurements. The lignin esters were applied on paperboard and formed a continuous film. The moisture barrier property of the coated paperboards was characterized by the water vapor transmission rate (WVTR). A significant decrease in WVTR was observed, for example, 40 g m-2 (for 24 h) for a paperboard coated with 10.4 g m-2 hardwood kraft lignin palmitate. The contact angle of water on the lignin ester coatings was high and stable. For all paperboard samples coated with lignin esters, a significant decrease in oxygen transmission rate was observed. Accordingly, lignin palmitate and laurate have a high potential as a barrier materials in packaging applications.


2012 ◽  
Vol 200 ◽  
pp. 180-185 ◽  
Author(s):  
Zhi Qiang Fang ◽  
Gang Chen ◽  
Yu Sha Liu ◽  
Xin Sheng Chai

Chitosan solution was applied to coated ivory board as a barrier material, and the surface microstructure, oxygen resistance and water vapor permeability of chitosan-coated paper under different coating weight were studied. According to the images of scanning electron microscope(SEM) and Atomic force microscope(AFM), the coated ivory board surface has a smooth contour without pores and cracks after coating with chitosan. Increasing in coating hold-out of chitosan, the smoothness and the oxygen barrier properties of coated paper were improved considerably, but no improvement on water vapor resistance. An Oxygen transmission rate (OTR) of 119.0 cm3/m2•24h•0.1MPa was obtained when the coating weight of chitosan was 3.96 g/m2. Single-layer and double-layer techniques were used to coat coated ivory paper with chitosan; it was found that the OTR of paper, obtaining by double-layer coating technique, was lower than that of single-layer paper at similar coating weight. For the purpose of reducing water vapor transmission rate (WVTR) of chitosan-coated paper, Poly(vinyldene chloride)(PVDC) was applied on the chitosan-coated paper. Water vapor and oxygen barrier properties were enhanced as the coating weight of PVDC increased from 1.05 g/m2to 7.40 g/m2. While the chitosan and PVDC was coated on coated ivory paper through bi-layer technique for 1.96 g/m2and 7.40g/m2, respectively, the WVTR and OTR of paper decreased by 66.3% and 98.0% separately, compared to that of the chitosan-coated paper for 1.96g/m2.


2011 ◽  
Vol 295-297 ◽  
pp. 1600-1605
Author(s):  
Gai Mei Zhang ◽  
Qiang Chen ◽  
Cun Fu He ◽  
Shou Ye Zhang

The oxygen transmission rate (OTR) of SiOx coated polyethylene terephthalate (PET) and biaxially oriented polypropylene (BOPP) affected by fine defects is discussed in this paper. With an ultrasonic AFM (UAFM), which is an advantageous to distinguishing tiny defects on/ in the deposited films, it is found that the OTR of the coated films is relevant to the morphology scanned by UAFM. Herein SiOx layers with a thickness in the order of nano-scale were fabricated in 13.56 MHz-radio frequency (RF) -plasma-enhanced chemical vapor deposition (PECVD). The monomer for the coating fabrication is hexamethyldisiloxane (HMDSO). Fourier transform inferred (FTIR) spectra of the deposited coating with a strong peak at 1062 cm-1, corresponding to Si-O-Si stretching vibration, confirm the formation of SiOx coatings through PECVD. The higher OTR value of SiOx coated PET is consistence with defects on film surface and in the subsurface of coatings through UAFM. It obtains that the OTR value of the defect free SiOx coated film was reduced by ca. 89% compared with the defect existence SiOx coated PET.


e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Ana Ares ◽  
María J Abad ◽  
Luis Barral ◽  
Sandra García-Garabal

AbstractThe aim of this work is to investigate the properties of the PP/EVOH films for their potential use in the packaging industry. Besides, the barrier properties, the mechanical parameters and the morphology of the PP/EVOH films have been studied as function of their composition and the processing technique used for their manufacture. In these applications, the package is frequently in contact with humidity environments and for this, it is necessary to know how environments with different humidity contents, affect the O2 permeability of the polymer material. For these reasons, the influence of the moisture in the values of permeability was evaluated too. The data showed that the oxygen transmission rate (O2TR) decreased with the amount of EVOH, and if the copolymer mass is maintained constant, the O2TR diminished with the quantity of the ionomer in the compositions. Besides, the films obtained by extrusion and following unidirectional stretching, presented better barrier properties to the oxygen molecules than the compression moulded films. When the ionomer is added to the compositions the permeability is reduced even for the films maintained in wet atmosphere. The micrographs obtained by SEM showed that the films have a biphasic structure, where the EVOH particles are dispersed in the PP matrix.


Author(s):  
Umair Qasim ◽  
Ahmed I. Osman ◽  
Ala’a H. Al-Muhtaseb ◽  
Charlie Farrell ◽  
Mohammed Al-Abri ◽  
...  

Abstract The extensive use of petroleum-based synthetic and non-biodegradable materials for packaging applications has caused severe environmental damage. The rising demand for sustainable packaging materials has encouraged scientists to explore abundant unconventional materials. For instance, cellulose, extracted from lignocellulosic biomass, has gained attention owing to its ecological and biodegradable nature. This article reviews the extraction of cellulose nanoparticles from conventional and non-conventional lignocellulosic biomass, and the preparation of cellulosic nanocomposites for food packaging. Cellulosic nanocomposites exhibit exceptional mechanical, biodegradation, optical and barrier properties, which are attributed to the nanoscale structure and the high specific surface area, of 533 m2 g−1, of cellulose. The mechanical properties of composites improve with the content of cellulose nanoparticles, yet an excessive amount induces agglomeration and, in turn, poor mechanical properties. Addition of cellulose nanoparticles increases tensile properties by about 42%. Barrier properties of the composites are reinforced by cellulose nanoparticles; for instance, the water vapor permeability decreased by 28% in the presence of 5 wt% cellulose nanoparticles. Moreover, 1 wt% addition of filler decreased the oxygen transmission rate by 21%. We also discuss the eco-design process, designing principles and challenges.


Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1082 ◽  
Author(s):  
Dongmei Han ◽  
Yiqing Luo ◽  
Qing Ju ◽  
Xujing Xiao ◽  
Min Xiao ◽  
...  

Nanobrick wall hybrid coating with super oxygen barrier properties were fabricated on polyethylene terephthalate (PET) film using a quadlayer (QL) assembly of polyelectrolytes and nanoplateles. A quadlayer assembly consists of three repeat units of polyacrylic acid (PAA), poly (dimethyl diallyl ammonium chloride) (PDDA) and layered α-zirconium phosphate (α-ZrP). PDDA with positive charges can assemble alternatively with both α-ZrP and PAA with negative charges to form nanobrick wall architectures on the surface of PET film via the electrostatic interaction. The lamellar structure of α-ZrP platelets and the dense QL assembly coating can greatly reduce the oxygen transmission rate (OTR) of PET film. Compared to pristine PET film, the OTR of PET (QL)19 is reduced from 57 to 0.87 cc/m2/day. Moreover, even with 19 QLs coating, PET (QL)19 composite film is still with an optical transparency higher than 90% and a haze lower than 10%. Therefore, the transparent PET (QL)n composite films with super oxygen barrier properties show great potential application in food packaging and flexible electronic packaging.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 705
Author(s):  
Juan Felipe Castro-Landinez ◽  
Felipe Salcedo-Galan ◽  
Jorge Alberto Medina-Perilla

This research reports the influence of polar monomer contents in ethylene vinyl acetate copolymer (EVA) and ethylene vinyl alcohol copolymer (EVOH) on the morphology, mechanical and barrier properties of polypropylene/ethylene copolymer (PP) reinforced with organically modified montmorillonite (MMT). PP/EVA and PP/EVOH (75/25 wt %) blends were reinforced with 3 wt % MMT in an internal mixer system. Samples were compression-molded into films of 300μ μm. The structural characterization was made using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), the mechanical properties were obtained by tension tests and the barrier properties by oxygen transmission rate (OTR). XRD patterns showed a combination of intercalated/exfoliated morphologies for the MMT, with higher d-001 interplanar distance increments for the blends with higher content of polar functional groups. SEM and TEM micrographs complement the results of the XRD analysis and show differences in the morphologies depending on the miscibility of the polyolefin and the polar monomer copolymer. Mechanical properties and oxygen permeability of composites exhibited a higher improvement, by the addition of MMT, for higher intermolecular interactions and most miscible polymeric system of the EVA. These results show that the higher the number of interactions, given by the VA or OH polar functional groups, the morphology and the miscibility between polyolefin and copolymer imply dispersion improvements of the nanocomposites and, in consequence, a higher improvement on the mechanical and barrier properties of the composite material.


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