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.

Dynamic and creep analysis of polyvinyl alcohol based films blended with starch and protein

2018 ◽  
Vol 39 (1) ◽  
pp. 35-47 ◽  
Author(s):  
Naman Jain ◽  
Vinay K. Singh ◽  
Sakshi Chauhan
Keyword(s):  
Polyvinyl Alcohol ◽  
Moisture Absorption ◽  
Viscoelastic Behavior ◽  
Mechanical Analysis ◽  
Cross Linking ◽  
Mechanical And Thermal Properties ◽  
Blend Films ◽  
Creep And Recovery ◽  
Degradation Temperature ◽  
Creep Analysis

Abstract The present study focuses on the fabrication and analyses of polyvinyl alcohol (PVA) based films blended with polymers, such as starch and protein. The aim is to improve the moisture absorption, solubility, mechanical and thermal properties of PVA by blending it with various polymers. The thermal cross-linking of the films has been studied by heating the films at 120°C for 4 h. The result shows that PVA was completely soluble in water, while post-blending solubility and moisture absorption of blended films decreased. The tensile strength of blended films was significantly higher (4%–29%) as compared to neat PVA, while thermally cross-linked films showed much higher strength (8%–174%). Blended films were characterized using Fourier transform infrared spectroscopy (FTIR) to confirm the formation of hydrogen bonds. Thermogravimetric analysis showed the increase in degradation temperature post-blending as compared to neat PVA. The viscoelastic behavior of the material as well as glass transition temperature was studied using dynamic mechanical analysis. Creep and recovery behavior were examined to study the effect of stress and temperature on creep strain. The biodegradability of the blended films was increased post-blending. This study showed that PVA based blend films can replace non-biodegradable plastics and hence are necessary for the development of environmentally friendly materials.

Chemiluminescence measurement of gel times for amine-cured epoxy resins

1995 ◽  
Vol 7 (2) ◽  
pp. 219-236 ◽  
Author(s):  
K A Kozielski ◽  
N C Billingham ◽  
G A George ◽  
D C L Greenfield ◽  
J M Barton
Keyword(s):  
Chemical Reactions ◽  
Epoxy Resins ◽  
Physical State ◽  
Glycidyl Ether ◽  
Cross Linking ◽  
Gel Time ◽  
The Matrix ◽  
Effect Of Impurities ◽  
The Cross

The cross-linking reactions of 4,4'-diaminodiphenyl sulphone (DDS) with stoichiometric quantities of glycidyl ether- or tetraglycidyl amine-based epoxy resins were monitored using chemiluminescence (CL) and rheometry. It was found that, when a sample was cured isothermally in air, the CL profile increased to a maximum, then decreased again. The maximum was found to correspond well with the gel time (tgel), as measured by rheometry. This observation is discussed in relation to the chemical reactions occurring within the material and the physical state of the matrix. The effect of impurities in DDS on the gel time of these epoxy resins is reported.

Effect of Microwave Irradiation on the Cross-Linking of Polyvinyl Alcohol

2005 ◽  
Vol 78 (7) ◽  
pp. 1158-1161 ◽  
Author(s):  
N. V. Petrova ◽  
A. M. Evtushenko ◽  
I. P. Chikhacheva ◽  
V. P. Zubov ◽  
I. V. Kubrakova
Keyword(s):  
Microwave Irradiation ◽  
Polyvinyl Alcohol ◽  
Cross Linking ◽  
The Cross

scholarly journals Dynamic Mechanical Thermal Analysis of Wood Polymer Composite Endurance to Prolonged Ultra Violet Irradiation Exposure

2018 ◽  
Vol 7 (4.34) ◽  
pp. 441
Author(s):  
A. Shahrizan M.Z. ◽  
Anika Zafiah M. Rus ◽  
Nur Munirah A. ◽  
M. Zulkhairi J. ◽  
N. Afiqah Sufian ◽  
...  
Keyword(s):  
Viscoelastic Properties ◽  
Ultra Violet ◽  
Mechanical Analysis ◽  
Morphological Properties ◽  
Dynamic Mechanical ◽  
Wood Polymer ◽  
Before And After ◽  
The Matrix ◽  
Wood Polymer Composites ◽  
Rice Husk Flour

This study was constructed to examine the viscoelastic properties and the microstructure of wood-plastic composites (WPCs) before and after being subjected to UV irradiation. The pellet of the wood polymer composites consists of polypropylene as the matrix and rice-husk flour as the reinforcing filler. The samples were UV irradiated from 5000 hours to 20,000 hours with the increment of 5000 hours to study the effect of weathering on the viscoelastic properties of the WPCs. The microstructures of the surface of the samples were examined using Optical Microscopy (OM). The mechanical properties of WPCs through dynamic mechanical analysis test were assessed for both polyvinyl chloride (PVC) and polypropylene (PP) samples. The value of storage modulus (E’) decreases when been exposed in the ultra violet irradiation, in both glassy and rubbery states. Moreover, the density of the WPC samples is closed to light weight and result is comparable. As for morphological properties test, the surface of cracked, voids appeared at the surface of the WPC samples of both PVC and PP interface and the density of composite decreased.  

scholarly journals A novel fibre-ensemble level constitutive model for exogenous cross-linked collagenous tissues

2016 ◽  
Vol 6 (1) ◽  
pp. 20150090 ◽  
Author(s):  
Michael S. Sacks ◽  
Will Zhang ◽  
Silvia Wognum
Keyword(s):  
Constitutive Model ◽  
Soft Tissues ◽  
Fibrous Tissue ◽  
Collagen Fibre ◽  
Tissue Response ◽  
Loading Path ◽  
Cross Linking ◽  
The Matrix ◽  
The Cross ◽  
Collagenous Tissues

Exogenous cross-linking of soft collagenous tissues is a common method for biomaterial development and medical therapies. To enable improved applications through computational methods, physically realistic constitutive models are required. Yet, despite decades of research, development and clinical use, no such model exists. In this study, we develop the first rigorous full structural model (i.e. explicitly incorporating various features of the collagen fibre architecture) for exogenously cross-linked soft tissues. This was made possible, in-part, with the use of native to cross-linked matched experimental datasets and an extension to the collagenous structural constitutive model so that the uncross-linked collagen fibre responses could be mapped to the cross-linked configuration. This allowed us to separate the effects of cross-linking from kinematic changes induced in the cross-linking process, which in turn allowed the non-fibrous tissue matrix component and the interaction effects to be identified. It was determined that the matrix could be modelled as an isotropic material using a modified Yeoh model. The most novel findings of this study were that: (i) the effective collagen fibre modulus was unaffected by cross-linking and (ii) fibre-ensemble interactions played a large role in stress development, often dominating the total tissue response (depending on the stress component and loading path considered). An important utility of the present model is its ability to separate the effects of exogenous cross-linking on the fibres from changes due to the matrix. Applications of this approach include the utilization in the design of novel chemical treatments to produce specific mechanical responses and the study of fatigue damage in bioprosthetic heart valve biomaterials.

scholarly journals Effect of Phenolic Resin Oligomer Motion Ability on Energy Dissipation of Poly (Butyl Methacrylate)/Phenolic Resins Composites

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 490
Author(s):  
Xing Huang ◽  
Songbo Chen ◽  
Songhan Wan ◽  
Ben Niu ◽  
Xianru He ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Hydrogen Bonding ◽  
Glass Transition ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Butyl Methacrylate ◽  
Scanning Calorimetry ◽  
Phenolic Resins ◽  
Dynamic Mechanical ◽  
The Matrix

Poly (butyl methacrylate) (PBMA) was blended with a series of phenolic resins (PR) to study the effect of PR molecular weight on dynamic mechanical properties of PBMA/PR composites. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) found a similar variation of glass transition temperature (Tg). The maximum loss peak (tanδmax) improved in all PBMA/PR blends compared with the pure PBMA. However, tanδmax reduced as the molecular weight increased. This is because PR with higher molecular weight is more rigid in the glass transition zone of blends. The hydrogen bonding between PBMA and PR was characterized by Fourier transform infrared spectroscopy (FTIR). Lower molecular weight PR formed more hydrogen bonds with the matrix and it had weaker temperature dependence. Combined with the results from DMA, we studied how molecular weight affected hydrogen bonding and thus further affected tanδmax.

scholarly journals Rheological and Dynamic Mechanical Properties of Abutilon Natural Straw and Polylactic Acid Biocomposites

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Hua Wang ◽  
Hafeezullah Memon ◽  
Elwathig A. M. Hassan ◽  
Tienah H. H. Elagib ◽  
Fadl Elmoula A. A. Hassan ◽  
...  
Keyword(s):  
Polylactic Acid ◽  
Natural Fibers ◽  
Melting Behavior ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Differential Scanning Calorimetric ◽  
Melt Blending ◽  
Alternative Reinforcement ◽  
Dynamic Mechanical ◽  
The Matrix

Recently, natural fibers have become attractive materials to engineers, scientists, and researchers as an alternative reinforcement for biocomposites. In this study, polylactic acid/abutilon natural straw biocomposites with various abutilon straw weight fractions were prepared by melt blending. The differential scanning calorimetric (DSC) results showed a significant influence of the abutilon straw on the melting behavior of PLA, even at the low abutilon straw contents. The dynamic mechanical analysis demonstrated that the storage modulus, as well as tan delta of the biocomposites, increased when the abutilon straw content increases, which indicates better interaction between abutilon natural straw and PLA. The incorporation of abutilon straw into biocomposites provided favorable changes in rheology related to the matrix. SEM observation revealed good dispersion of the abutilon straw in PLA.

Temperature Dependent Dynamic Mechanical Properties of Hydrogenated Nitrile Butadiene Rubber and the Effect of Peroxide Cross-linkers

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Blaž Likozar ◽  
Matjaž Krajnc
Keyword(s):  
Mechanical Properties ◽  
Cyano Group ◽  
Viscoelastic Behavior ◽  
Dynamic Mechanical Properties ◽  
Cross Linking ◽  
Butadiene Rubber ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Nitrile Butadiene Rubber ◽  
The Cross

AbstractThe viscoelastic behavior of hydrogenated nitrile butadiene rubber (HNBR) was studied over a range of temperatures and shear frequencies. Dynamic mechanical properties were studied and modelled using the generalized Maxwell model and the Williams-Landel-Ferry equation. A fitting algorithm was developed to provide the best agreement between the experimental data and the model results. In addition to dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC) was applied. The HNBR structure was characterized by X-ray diffraction (XRD). The developed model exhibited an excellent agreement with either isothermal or dynamic experiment data, yet only up to the rubbery plateau, after which a structure ordering occurred. This was explained by the cyano group secondary bonding and consequentially the cross-linking between HNBR chains. A molecular modeling simulation was made to confirm the cross-linking. The effect of peroxide cross-linking agents in a compound resembled the one usually observed in the filler formulated compounds.

Sodium Lignosulphonate-Polyvinyl Alcohol Bioadsorbent: Synthesis, Characterization and Adsorption for Pb (II)

2009 ◽  
Vol 620-622 ◽  
pp. 193-196 ◽  
Author(s):  
Xiao Qing Luo ◽  
Xiao Yan Lin ◽  
Xue Gang Luo ◽  
Yan Chen
Keyword(s):  
Polyvinyl Alcohol ◽  
Water Solubility ◽  
Adsorption Process ◽  
Suspension Polymerization ◽  
High Water ◽  
Reversed Phase ◽  
Cross Linking ◽  
Static Force ◽  
Initial Ph ◽  
High Water Solubility

A novel sodium lignosulphonate (SLS)-polyvinyl alcohol (PVA) spherical macroporous bioadsorbent (SLSP) was synthesized by reversed phase suspension polymerization. Comparing with powdery and high water solubility SLS, this new spherical bioadsorbent exhibited relative stability under static force. SEM and FTIR proved the cross-linking of SLS and PVA. TG curves of SLS and SLSP indicated that the thermal property of SLS had been improved by cross-linking modification. Meanwhile, comprehensive adsorption study of Pb (II) on this bioadsorbent was conducted regarding the effects of time, initial PH and initial Pb (II) concentration. 90% of Pb (II) from aqueous solution could be removed by 0.4g of the adsorbent at 25°C for less than 3h. The adsorption process was determined to be consistent with the Langmuir isotherm.

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