scholarly journals Mitigating the Impact of Cellulose Particles on the Performance of Biopolyester-Based Composites by Gas-Phase Esterification

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 200 ◽  
Author(s):  
Grégoire David ◽  
Nathalie Gontard ◽  
Hélène Angellier-Coussy
Keyword(s):  
Gas Phase ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Stress And Strain ◽  
Moisture Sensitivity ◽  
Natural Systems ◽  
Palmitoyl Chloride ◽  
Diffusion Parameters ◽  
Dispersion State ◽  
The Impact

Materials that are both biodegradable and bio-sourced are becoming serious candidates for substituting traditional petro-sourced plastics that accumulate in natural systems. New biocomposites have been produced by melt extrusion, using bacterial polyester (poly(3-hydroxybutyrate-co-3-hydroxyvalerate)) as a matrix and cellulose particles as fillers. In this study, gas-phase esterified cellulose particles, with palmitoyl chloride, were used to improve filler-matrix compatibility and reduce moisture sensitivity. Structural analysis demonstrated that intrinsic properties of the polymer matrix (crystallinity, and molecular weight) were not more significantly affected by the incorporation of cellulose, either virgin or grafted. Only a little decrease in matrix thermal stability was noticed, this being limited by cellulose grafting. Gas-phase esterification of cellulose improved the filler’s dispersion state and filler/matrix interfacial adhesion, as shown by SEM cross-section observations, and limiting the degradation of tensile properties (stress and strain at break). Water vapor permeability, moisture, and liquid water uptake of biocomposites were increased compared to the neat matrix. The increase in thermodynamic parameters was limited in the case of grafted cellulose, principally ascribed to their increased hydrophobicity. However, no significant effect of grafting was noticed regarding diffusion parameters.

scholarly journals Upcycling of Vine Shoots: Production of Fillers for PHBV-Based Biocomposite Applications

2020 ◽  
Author(s):  
Grégoire David ◽  
Laurent Heux ◽  
Stéphanie Pradeau ◽  
Nathalie Gontard ◽  
Hélène Angellier-Coussy
Keyword(s):  
Water Vapor ◽  
Gas Phase ◽  
Mechanical Performance ◽  
Low Cost ◽  
Water Vapor Permeability ◽  
Contact Angles ◽  
Vapor Permeability ◽  
Water Contact ◽  
Median Diameter ◽  
Cost Of Materials

Abstract This paper aims at investigating the potential of vine shoots (ViSh) upcycling as fillers in novel poly(3-hydroxybutyrate-3-hydroxyvalerate) (PHBV) based biocomposites. ViSh particles of around 50 µm (apparent median diameter) were obtained combining dry grinding processes, and mixed with PHBV using melt extrusion. Thermal stability and elongation at break of biocomposites were reduced with increasing contents of ViSh particles (10, 20 and 30 wt%), while Young’s modulus and water vapor permeability were increased. It was shown that a surface gas-phase esterification allowed to significantly increase the hydrophobicity of ViSh particles (increase of water contact angles from 59° to 114°), leading to a reduction of 27% in the water vapor permeability of the biocomposite filled with 30 wt% of ViSh. The overall mechanical performance was not impacted by gas-phase esterification, demonstrating that the interfacial adhesion between the virgin ViSh particles and the PHBV matrix was already good and that such filler surface treatment was not required in that case. It was concluded that ViSh particles can be interestingly used as low cost fillers in PHBV-based biocomposites to decrease the overall cost of materials.

scholarly journals Influence of Fabric Weave on Thermal Radiation Resistance and Water Vapor Permeability

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 525
Author(s):  
Ana Kiš ◽  
Snježana Brnada ◽  
Stana Kovačević
Keyword(s):  
High Temperatures ◽  
High Performance ◽  
Thermal Protection ◽  
Water Vapor Permeability ◽  
Radiant Heat ◽  
The Body ◽  
Vapor Permeability ◽  
Weave Structure ◽  
Fabric Structures ◽  
The Impact

In this work, aramid fibers were used to develop new, high-performance fabrics for high-temperature protective clothing. The research was based on the impact of the weave structure on fabric resistance to radiant heat. The goals of the research were primarily related to the development of new fabric structures created by the weave structure, which gives better protection of the body against high temperatures in relation to the standard weave structures that are used today. According to the results obtained it can be concluded that the fabric weave significantly affects the fabric structure, which consequently determines the effectiveness of protection against high temperatures. The justification for the use of multi-weft and strucks weave structure, which provides greater thermal protection and satisfactory breathability than commonly used weave structures, was ascertained.

Environmental-Friendly Soy Protein Isolate/Poly (Vinyl Alcohol) Blend Packaging Films: Water Vapor Permeability

2010 ◽  
Vol 96 ◽  
pp. 75-79 ◽  
Author(s):  
Jun Feng Su ◽  
Wen Long Xia ◽  
Wen Li ◽  
Ke Man Jin
Keyword(s):  
Water Vapor ◽  
Soy Protein ◽  
Vinyl Alcohol ◽  
Soy Protein Isolate ◽  
Water Vapor Permeability ◽  
Protein Isolate ◽  
Poly Vinyl Alcohol ◽  
Vapor Permeability ◽  
Glycerol Water ◽  
Moisture Sensitivity

The aim of the present work was to investigate the moisture sensitivity of soy protein isolate (SPI) films blending with poly (vinyl alcohol) (PVA) plasticized by glycerol. Water vapor permeability (WVP) was measured based on the contents of PVA and glycerol in films. WVP values of various SPI/PVA films with/without glycerol were in the range of 8.25 and 10.9 g mm/m2 h kPa. The results showed that WVP values decreased with the increasing content of PVA. Moreover, XRD tests confirmed that the glycerol would insert into the macromolecular blending structure and destroy the crystalline of blends, and the crosslinkage between glycerol molecules and SPI reduced the interstitial spaces in protein matrix, thus allowing for decreasing diffusion rate of water molecules through the films.

scholarly journals The Impact of the Mechanical Modification of Bacterial Cellulose Films on Selected Quality Parameters

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1275
Author(s):  
Izabela Betlej ◽  
Renata Salerno-Kochan ◽  
Agnieszka Jankowska ◽  
Krzysztof Krajewski ◽  
Jacek Wilkowski ◽  
...  
Keyword(s):  
Bacterial Cellulose ◽  
Water Vapor Permeability ◽  
Quality Parameters ◽  
Vapor Permeability ◽  
Physical Parameters ◽  
Significant Information ◽  
Cellulose Films ◽  
Native Cellulose ◽  
Modified Polymer ◽  
The Impact

This study investigated the effect of the homogenization of bacterial cellulose particles and their reintegration into a membrane on the mechanical and physical parameters of the films produced from them in relation to films made of native cellulose (not subjected to the homogenization process). Bacterial cellulose was obtained from a culture of microorganisms forming a conglomerate of bacteria and yeast, called SCOBY. The research has shown that the mechanical modification of bacterial cellulose contributes to an increase in the elongation of the material. Modified polymer films were characterized by a higher Young’s modulus and a much higher breaking force value compared to native cellulose. The mechanical modification of cellulose contributed to an increase in hygroscopicity and changes in water vapor permeability. The obtained results may provide significant information on the methods of modifying bacterial cellulose, depending on its various applications.

scholarly journals The use of an internal airtight membrane in CLT external wall in terms of hygrothermal performance

2021 ◽  
Vol 2069 (1) ◽  
pp. 012208
Author(s):  
V. Kukk ◽  
J. Kers ◽  
T. Kalamees
Keyword(s):  
Water Vapor Permeability ◽  
Stochastic Approach ◽  
High Water ◽  
Vapor Permeability ◽  
Diffusion Resistance ◽  
Mold Growth ◽  
External Wall ◽  
Hygrothermal Performance ◽  
Dry Out ◽  
The Impact

Abstract This study focused on the dry-out capacity of the vapor-permeable CLT (cross-laminated timber) external wall and the impact of using an internal airtight membrane. The results of the work were obtained first from the field measurements, after which the simulation model was created and validated, and the hygrothermal performance of the wall was analyzed by a stochastic approach. The results of this showed that the CLT dries out quickly and safely in a wall assembly with a high water vapor permeability, even with the large range of initial CLT MC (13-25%). When an additional airtight layer with high vapor diffusion resistance (Sd of 244 m) is added between the insulation and the CLT, the dry-out capacity of the CLT decreases significantly and there is a high probability of mold growth on the CLT surface. The risk of mold growth can be prevented when the vapor resistance (Sd) of the airtight layer is reduced to 1.5 m in a case where initial CLT MC is up to 25% and in a case where initial MC is up to 20%, the vapor resistance of an airtight layer must be reduced to 3 m.

scholarly journals Influence of the Graphene Filler Nature on the Morphology and Properties of Melt Blended EVOH Based Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3546
Author(s):  
Anthony Blanchard ◽  
Fabrice Gouanvé ◽  
Eliane Espuche
Keyword(s):  
Water Vapor Permeability ◽  
Young Modulus ◽  
Expanded Graphite ◽  
Barrier Properties ◽  
High Water ◽  
Nanocomposite Films ◽  
Simultaneous Increase ◽  
Vapor Permeability ◽  
Ethylene Vinyl Alcohol ◽  
Dispersion State

In this study, ethylene vinyl alcohol (EVOH) nanocomposites elaborated by melt blending with four different fillers were investigated. Two graphene and two graphite fillers displaying various shapes were selected. The morphology, microstructure, thermal, mechanical, and barrier properties of the nanocomposite films prepared for 2 wt% fillers were analyzed with the aim to establish structure–function properties relationships. The nanocomposites properties significantly depended on the nature of the incorporated filler. The nanocomposite film prepared with the expanded graphite filler exhibited the highest Young modulus value (E = 1430 MPa) and the best barrier properties. Indeed, barrier properties, rarely studied at high water activities, evidenced a significant improvement with a decrease of the water vapor permeability by a factor 1.8 and of the oxygen permeabilities by a factor close to 2, for a critical water activity higher than 0.95. An increase of the thermal stability was also evidenced for this nanocomposite. It was shown that for all studied nanocomposites, the properties could be related to the dispersion state of the fillers and the simultaneous increase of the crystallinity of the matrix. A specific equation was proposed to take into account these both parameters to accurately predict the nanocomposite barrier properties.

scholarly journals Water Vapor Permeability through PAN Nanofiber Mat with Varying Membrane-Like Areas

2019 ◽  
Vol 27 (1(133)) ◽  
pp. 12-15 ◽  
Author(s):  
Lilia Sabantina ◽  
Lilia Sabantina ◽  
Lubos Hes ◽  
José Rodríguez Mirasol ◽  
Tomás Cordero ◽  
...  
Keyword(s):  
Water Vapor ◽  
High Voltage ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
High Voltage Electrode ◽  
Vapour Permeability ◽  
Thin Membranes ◽  
Nanofiber Mats ◽  
The Impact ◽  
Pan Nanofiber

Electrospinning can be used to create nanofiber mats from diverse polymers which can be used as filters etc. Depending on the spinning parameters, also nano-membranes, i.e. non-fibrous mats, can be produced as well as mixtures from both morphologies. The ratio of membrane to fibrous areas can be tailored by the distance between the high voltage electrode and substrate. Here the impact of the mat morphology on the water vapour permeability through polyacrylonitrile nanofiber mats with different membrane-like areas is shown, allowing for tailoring the permeability between 0.1 Pa · m²/W and more than 10 Pa · m²/W. In this way it is possible to create the finest filters as well as nearly impenetrable thin membranes with the same technology.

scholarly journals On the importance of desiccant during the determination of water vapor permeability of permeable insulation material

2020 ◽  
Vol 172 ◽  
pp. 14003
Author(s):  
Thibaut Colinart ◽  
Patrick Glouannec
Keyword(s):  
Water Vapor ◽  
Building Materials ◽  
Wood Fiber ◽  
Construction Materials ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Diffusion Resistance ◽  
Insulation Material ◽  
The Impact

Water vapor permeability of building materials is usually measured using dry cup test according to the ISO 12572 standard. For this test, suitable adsorbing desiccant should be used to provide stable low vapor pressure conditions within the cup and, thus, to ensure the good accuracy of the measurement. In this work, different adsorbing desiccants mentioned in the ISO 12572 standard are tested for measurements performed on wood fiber insulation. For each experiment, relative humidity is monitored inside the dry cup. The results indicate that 0 %RH is not reached inside the dry cup and boundary condition is not always stable for highly permeable construction materials, depending on the adsorbing desiccants. The impact of these observation is evaluated on the determination of water vapor diffusion resistance factor and compared to other sources of uncertainties.

Physical Properties and Antibacterial Activity of a Chitosan Film Incorporated with Lavender Essential Oil

2013 ◽  
Vol 706-708 ◽  
pp. 197-200 ◽  
Author(s):  
Zhi Hong Zhang ◽  
Yu Yue Qin ◽  
Jian Fan ◽  
Tian Rui Zhao ◽  
Chun Sheng Cheng
Keyword(s):  
Mechanical Property ◽  
Antibacterial Activity ◽  
Water Vapor ◽  
Essential Oil ◽  
Food Packaging ◽  
Chitosan Film ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Active Food Packaging ◽  
The Impact

Chitosan-based films containing lavender essential oil (LEO) (0, 0.5%, 1.0%, 1.5% (v/v)) were prepared to evaluate their physical and antibacterial activities. In order to study the impact of the incorporation of LEO into chitosan matrix, the solubility, mechanical property, water vapor permeability, and antibacterial activity of the films were investigated. Fourier transform infrared chromatography (FTIR) was carried out to explain structure–property relationships. Results showed that the solubility and water vapor permeability of the chitosan-based film decreased by LEO incorporation. Films containing LEO showed better mechanical property. FTIR spectra demonstrated good interaction between functional groups of chitosan with LEO. With the concentration of LEO increased from 0 to 1.5 %, the inhibitory zone of four bacterial strains (Escherichia coli, Staphylococcus aurous, Bacillus magaterium, Bacillus subtilis) increased. It can be concluded that chitosan films containing LEO can be used for development of active food packaging materials.

Ultraviolet blocking and antioxidant polyvinyl alcohol films incorporated with baicalin extraction from Scutellaria baicalensis Georgi

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jinshu Liu ◽  
Xiaoyan Ma ◽  
Wenzhao Shi ◽  
Jianwei Xing ◽  
Chaoqun Ma ◽  
...  
Keyword(s):  
Water Vapor ◽  
Polyvinyl Alcohol ◽  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Water Vapor Permeability ◽  
Scutellaria Baicalensis ◽  
Vapor Permeability ◽  
Protective Film ◽  
Uv Blocking

Abstract Baicalin, an active flavonoid ingredient of Scutellaria baicalensis Georgi, was extracted by heat reflux extraction and showed the same significance UV absorption property with standard baicalin. Active films were prepared from polyvinyl alcohol (PVA) containing baicalin extract by casting method. The effect of baicalin extracts on the UV-blocking, optical, antioxidant property, water vapor permeability, swelling and mechanical properties of the films were studied. UV–vis transmittance spectra showed that PVA films incorporated with baicalin extract blocked ultraviolet light range from 280–400 nm even with low concentration of baicalin (0.5 wt%) and maintain the high transparency in visible spectrum. The outstanding UV-blocking properties of PVA films incorporated with baicalin extract were also confirmed by Rhodamine B degradation. Baicalin conferred antioxidant properties to PVA films as determined by DPPH radical scavenging activity. Due to the interaction between hydroxy groups of baicalin and PVA molecule, water vapor permeability, swelling and elongation at break of the films were decreased accompanied with the increasing in tensile strength and Young’s modulus. FTIR reveal that the interaction between PVA molecules was significant changed by the introduction of baicalin. These results suggest that PVA film incorporated with baicalin extract can be used for the development of functional protective film.

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