Effect of acetylated cellulose nanocrystals on solid‐state foaming behaviors of chain‐extended poly(butylene adipate‐co‐terephthalate)

Cui, Yalin; Luo, Jingyun; Deng, Yafeng; Wang, Xiangdong; Zhou, Hongfu

doi:10.1002/vnl.21845

Cited by 12 publications

(5 citation statements)

References 63 publications

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“…This is an indication of the flow behavior of a viscoelastic fluid. However, the value reduces significantly to lower than 45° for the materials containing 1 wt% MWCNTs and higher, representing a transition from liquid‐like to solid‐like behavior of the system 46 . This indicates that the elastic behavior of the materials remarkably improves with an increase in the nanotubes concentration.…”

Section: Resultsmentioning

confidence: 93%

Rheological percolation, gel‐like behavior and electrical conductivity of multi‐walled carbon nanotubes filled ethylene‐vinyl acetate copolymer/acrylonitrile‐butadiene rubber nanocomposites

Razavi‐Nouri,

Salavati

2023

Polymer Composites

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Reasonable studies on the composite systems containing conductive nanoparticles are very important to manufacture the materials with physico‐mechanical tailor‐made properties. In this work, rheological percolation, gel‐like behavior and electrical properties of multi‐walled carbon nanotubes (MWCNTs) filled ethylene‐co‐vinyl acetate/acrylonitrile‐butadiene copolymer blends containing 0–7 wt% MWCNTs were studied. The Winter‐Chambon criterion validity was evaluated for physical gelation of the system. The rheological and electrical percolation threshold, gel point (Pg), relaxation exponent (n), gel strength (Sg), and the fractal dimension (df) at the gel point were calculated. The formation of physical gel and rheological percolation threshold were both found to occur at 1 wt% MWCNTs concentration. Based on the df value determined, it was revealed that the system behaved similar to the one in which the excluded volume interactions were nearly screened. It was also found that the storage modulus (G′) near the Pg followed a power‐law scaling relationship in the form where is the distance from Pg. The electrical conductivity of the nanocomposites increased with the increase in MWCNTs loading after the nanofillers content surpassed a certain value. A schematic model was proposed to demonstrate the variation of electrical conduction with the increase in MWCNTs concentration. The excluded volume and hard‐core models were also employed to estimate the average aspect ratio of the nanofillers embedded in the system.Highlights Morphology and gel‐like behavior of EVA/NBR/MWCNTs system were studied Winter‐Chambon criterion was found to be valid for the gelation of the system Rheological percolation and gel point were occurred at the same MWCNTs loading It was found excluded volume interactions were nearly screened at gel point A schematic model for microstructure development was suggested for the system

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Section: Resultsmentioning

confidence: 93%

Rheological percolation, gel‐like behavior and electrical conductivity of multi‐walled carbon nanotubes filled ethylene‐vinyl acetate copolymer/acrylonitrile‐butadiene rubber nanocomposites

Razavi‐Nouri,

Salavati

2023

Polymer Composites

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“…Tan δ is a crucial quantity to investigate the contribution of viscous to elastic, which is defined as the ratio loss modulus/ G '. In Figure 3C, the tan δ of PHBV nanocomposites decreases significantly compared with pure PHBV, indicating that PHBV nanocomposites had faster elastic response and higher melt elasticity, which was conducive to ameliorate foaming properties 38,43 . Noteworthily, after the addition of CNTs and/or GNPs, the tan δ of PHBV nanocomposites were all less than 1.…”

Section: Resultsmentioning

confidence: 96%

“…In Figure 3C, the tanδ of PHBV nanocomposites decreases significantly compared with pure PHBV, indicating that PHBV nanocomposites had faster elastic response and higher melt elasticity, which was conducive to ameliorate foaming properties. 38,43 Noteworthily, after the addition of CNTs and/or GNPs, the tanδ of PHBV nanocomposites were all less than 1. The decrement of tanδ manifested that the viscoelastic response behavior of PHBV specimens transformed from viscous response to elastic response, that is to say, the occurrence of liquid-solid phase transition led to the reduction of viscous dissipation.…”

Section: Rheological Propertiesmentioning

confidence: 99%

Designing improved electromagnetic shielding efficacy of poly(3‐hydroxybutyrate‐co‐3hydroxyvalerate) nanocomposites foam using carbon nanotubes and graphene nanoplatelets

Wang

Wei

Bai

et al. 2023

Vinyl Additive Technology

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Nowadays, one of the design direction of bio‐derived and biodegradable polymer foams with multi‐functionalization is how to attain superior electromagnetic interference (EMI) shielding property, which has become a hot topic. Herein, bio‐based poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) foams filled with carbon nanotubes (CNTs) and/or graphene nanoplatelets (GNPs) were fabricated by supercritical carbon dioxide. As observed by optical microscope and scanning electron microscope, the CNTs and GNPs in PHBV matrix might gradually construct three kinds of network structures (CNTs‐CNTs, GNPs‐GNPs and GNPs‐CNTs network structures), which would improve the melt viscoelasticity, crystallization, electrical, dielectric and EMI shielding properties of PHBV. The complex viscosity and storage modulus of PHBV nanocomposites with the ratio of CNTs/GNPs as 1:1 rose nearly three orders of magnitudes than those of pure PHBV, in addition, its crystallization temperature and crystallinity increased remarkably to 122°C and 62%, individually. When the CNTs/GNPs ratio was 1:1 at a low total content of 3 wt%, PHBV nanocomposite and its foam implemented the high dielectric properties. Furthermore, the EMI specific shielding effectiveness of obtained PHBV was blend with 1.5 wt% CNTs and 1.5 wt% GNPs nanocomposite foam was the highest, reaching 19.3 dB cm3/g. This work paved a feasible way to the production of eco‐friendly PHBV nanocomposite foams for the application of electronics and aerospace industries.Highlights PHBV/CNTs/GNPs foams were prepared using a scCO2‐assisted foaming method. Dispersion of carbon fillers in PHBV was the best as CNTs/GNPs ratio was 1:1. G' of PHBV/C1.5/G1.5 specimens were increased by three orders of magnitude. EMI specific shielding effectiveness of PHBV/C1.5/G1.5 nanocomposite foam could reach 19.3 dB cm3/g.

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“…However, there are few studies and applications of PBAT as a foaming material. Cui et al prepared biodegradable branched PBAT (CPBAT)/acetylated cellulose nanocrystal (ACNC) nanocomposite foams using a batch foaming process with supercritical CO 2 [ 10 ]. Their study produced the highest volume-expansion ratio (VER) reported for PBAT foam in the literature at that time; however, the VER of their CPBAT foams was only 9.21.…”

Section: Introductionmentioning

confidence: 99%

High-Strength Bio-Degradable Polymer Foams with Stable High Volume-Expansion Ratio Using Chain Extension and Green Supercritical Mixed-Gas Foaming

Long

Shaoyu

et al. 2023

Polymers

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The preparation of biodegradable polymer foams with a stable high volume-expansion ratio (VER) is challenging. For example, poly (butylene adipate-co-terephthalate) (PBAT) foams have a low melt strength and high shrinkage. In this study, polylactic acid (PLA), which has a high VER and crystallinity, was added to PBAT to reduce shrinkage during the supercritical molded-bead foaming process. The epoxy chain extender ADR4368 was used both as a chain extender and a compatibilizer to mitigate the linear chain structure and incompatibility and improve the foamability of PBAT. The branched-chain structure increased the energy-storage modulus (G’) and complex viscosity (η*), which are the key factors for the growth of cells, by 1–2 orders of magnitude. Subsequently, we innovatively used the CO2 and N2 composite gas method. The foam-shrinkage performance was further inhibited; the final foam had a VER of 23.39 and a stable cell was obtained. Finally, after steam forming, the results showed that the mechanical strength of the PBAT/PLA blended composite foam was considerably improved by the addition of PLA. The compressive strength (50%), bending strength, and fracture load by bending reached 270.23 kPa, 0.36 MPa, and 23.32 N, respectively. This study provides a potential strategy for the development of PBAT-based foam packaging materials with stable cell structure, high VER, and excellent mechanical strength.

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Effect of acetylated cellulose nanocrystals on solid‐state foaming behaviors of chain‐extended poly(butylene adipate‐co‐terephthalate)

Cited by 12 publications

References 63 publications

Rheological percolation, gel‐like behavior and electrical conductivity of multi‐walled carbon nanotubes filled ethylene‐vinyl acetate copolymer/acrylonitrile‐butadiene rubber nanocomposites

Rheological percolation, gel‐like behavior and electrical conductivity of multi‐walled carbon nanotubes filled ethylene‐vinyl acetate copolymer/acrylonitrile‐butadiene rubber nanocomposites

Designing improved electromagnetic shielding efficacy of poly(3‐hydroxybutyrate‐co‐3hydroxyvalerate) nanocomposites foam using carbon nanotubes and graphene nanoplatelets

High-Strength Bio-Degradable Polymer Foams with Stable High Volume-Expansion Ratio Using Chain Extension and Green Supercritical Mixed-Gas Foaming

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