Effect of Time and Temperature when Removing PVA from a PET/PVA Nonwoven Material

2013 ◽  
Vol 821-822 ◽  
pp. 188-194
Author(s):  
Sizo Ncube ◽  
Chu Yang Zhang ◽  
Edison Omollo ◽  
Li Liu
Keyword(s):  
High Temperature ◽  
Polyvinyl Alcohol ◽  
Pore Size ◽  
Water Solubility ◽  
Nonwoven Material ◽  
Water Bath ◽  
Heating Period ◽  
Needle Punching ◽  
Needle Punching Machine

The study examined the effect of heat and time on fabrics made from polyester (PET) and polyvinyl alcohol (PVA) fibres which have different aerial densities and composed of 90% and 10% of PET and PVA respectively. PVA is included in the fabric due to its water solubility and this will allow the PVA to be removed thereby leaving a more porous fabric. The fabrics were passed through needle punching machine and PVA removed by heating in a water bath. The nonwoven fibre was then heated in water at temperatures of 75, 85 and 100 °C in an effort to remove the PVA fibres and leave a more porous fabric. While removing the PVA through heating in a water bath, the effect of heating period and the temperature on the fabric properties was investigated. The strength, elongation and structure of the fabric were investigated and the changes analysed. It was found that there was a significant removal of PVA at longer periods of time when at a high temperature. The effect on the properties was found to be higher with higher temperatures as well with a decrease in strength ranging between 40% and 60% being experienced while an increase in elongation, between 60% and 90% was experienced. Fibre spacing and pore size was found to have increased as well.

High temperature properties of MDF composite based on calcium aluminate cement and polyvinyl alcohol

2013 ◽  
Vol 115 (2) ◽  
pp. 1245-1252 ◽  
Author(s):  
František Šoukal ◽  
Petr Ptáček ◽  
Jiří Másilko ◽  
Tomáš Opravil ◽  
Jaromír Havlica ◽  
...  
Keyword(s):  
High Temperature ◽  
Polyvinyl Alcohol ◽  
Calcium Aluminate ◽  
Calcium Aluminate Cement ◽  
High Temperature Properties ◽  
Aluminate Cement

Decomposition Reaction of Polyvinyl Alcohol in High-Temperature and High-Pressure Water.

2001 ◽  
Vol 27 (5) ◽  
pp. 652-656 ◽  
Author(s):  
Nobuaki Sato ◽  
Takashi Saeki ◽  
Hiroyuki Daimon ◽  
Koichi Fujie
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Polyvinyl Alcohol ◽  
Decomposition Reaction ◽  
Pressure Water

Effect of a Low-Concentration H3PO4 Solution Application on High-Temperature Behaviour of Ti and Ti-Al Alloys

2009 ◽  
Vol 289-292 ◽  
pp. 69-75 ◽  
Author(s):  
S.Y. Brou ◽  
G. Bonnet ◽  
Jean Luc Grosseau-Poussard
Keyword(s):  
High Temperature ◽  
Titanium Content ◽  
Phosphoric Acid Solution ◽  
Al Alloys ◽  
Metallic Substrate ◽  
Aluminium Content ◽  
Barrier Effect ◽  
Time Increase ◽  
Heating Period ◽  
Temperature Behaviour

TiAl, TA6V and titanium coupons were treated by a phosphoric acid solution by dipping. They were then submitted to a heat treatment and, in the case of TiAl and TA6V, to high temperature discontinuous oxidation under laboratory air. The H3PO4 treatment allowed to decrease the mass gains for TiAl and TA6V, in particular during the first 100 hours. XRD analyses demonstrated for the three substrates the formation of a pyrophosphate layer during the heating period. This pyrophosphate evolved towards TiO2 with oxidation time increase, quicker for smaller aluminium content (or higher titanium content) in the metallic substrate. The decrease of mass gains was attributed to a diffusion barrier effect of the pyrophosphate layer as long as it was present.

Analysis and modeling of the pore size effect on the thermal conductivity of alumina foams for high temperature applications

2017 ◽  
Vol 43 (16) ◽  
pp. 13356-13363 ◽  
Author(s):  
Pedro I.B.G.B. Pelissari ◽  
Ricardo A. Angélico ◽  
Vânia R. Salvini ◽  
Diogo O. Vivaldini ◽  
Victor C. Pandolfelli
Keyword(s):  
Thermal Conductivity ◽  
High Temperature ◽  
Size Effect ◽  
Pore Size ◽  
Temperature Applications

The Synthesis and Characterization of PVA-Ketoprofen Cryogel, Biomaterial with Extended Drug Release Properties for Cartilage Replacement

2014 ◽  
Vol 216 ◽  
pp. 205-209
Author(s):  
Monica Cretan Stamate ◽  
Ciprian Stamate
Keyword(s):  
Articular Cartilage ◽  
Drug Release ◽  
Polyvinyl Alcohol ◽  
Water Solubility ◽  
Physicochemical Characterization ◽  
Gravimetric Method ◽  
Controlled Drug Release ◽  
High Wear Resistance ◽  
Mechanical Resistance ◽  
Swelling Properties

The present paper aims to study the possibility to modify the properties of polyvinyl alcohol (pva) cryogels prepared in the presence of ketoprofen in order to replace the damaged articular cartilage. Articular cartilage is the most important part of articulation characterized by very low friction, high wear resistance, and poor regenerative qualities. Polyvinyl alcohol is a non-expensive polymer, versatile and adaptable to various needs, with exceptional properties such as water solubility, biocompatibility, non-toxicity and with capability to form hydrogels by chemical or physical methods. The aims of this paper are the synthesis, the physicochemical characterization and analysis of the tribological properties of pva cryogels for cartilage replacement and the introduction of new concept in medication by creating the cryogel like a controlled drug release system. The morphology of the cryogels, the interaction between the pva macromolecular chains and medicament has been studied by Scanning Electronic Microscopy. The gels swelling in physiologic ser have been monitored by gravimetric method in order to evidence the hydrophilic properties. The mechanical properties of the cryogels have been investigated by dynamic mechanical measurements. In conclusion, the biomaterial obtained provides good swelling properties, mechanical resistance and it is ideal for extended drug release implantable systems.

Creep and dynamic mechanical behavior of cross-linked polyvinyl alcohol reinforced with cotton fiber laminate composites

2019 ◽  
Vol 39 (4) ◽  
pp. 326-335 ◽  
Author(s):  
Naman Jain ◽  
Shubhan Ali ◽  
Vinay K. Singh ◽  
Komal Singh ◽  
Nitesh Bisht ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Cotton Fiber ◽  
Water Solubility ◽  
Mechanical Analysis ◽  
Cross Linking ◽  
Laminate Composites ◽  
Dynamic Mechanical ◽  
The Matrix ◽  
The Cross ◽  
Uptake Test

AbstractThe objective of this investigation was to fabricate cross-linked polyvinyl alcohol (PVA) based laminate composites reinforced with biaxial cotton sheets. Cross-linking was done with sulfuric acid, to overcome the water solubility of PVA. A water uptake test was performed to evaluate the effect of cross-linking on the water absorption properties of the composites. Morphology, distribution and bonding between the matrix and reinforcement of the fabricated composites were studied using scanning electron microscopy. Mechanical properties such as the tensile strength (TS), modulus of elasticity and elongation of the fabricated composites material were evaluated. There was about a 56.25% increase in the TS of the cross-linked composite as compared to the neat PVA, and at 64 wt.% of cotton fiber, there was about a 56% increase in the TS as compared to the cross-linked PVA. The thermal degradation analysis of fabricated composites material was carried out by thermogravimetric analysis. The thermal stability increased with increase in cotton fiber wt.%. The viscoelastic properties of the fabricated composites material were determined by dynamic mechanical analysis. The effects of stress (4 MPa, 6 MPa and 8 MPa) and temperature (20°C and 40°C) on creep and recovery behavior of the laminated composites were studied.

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