Reinforcement of Stearic Acid Treated Egg Shell Particles in Epoxy Thermosets: Structural, Thermal, and Mechanical Characterization

This work reports the modification of egg shell (ES) particles by using stearic acid (SA) and their reinforcement in the epoxy matrix. The ES treatment via SA was optimized, the optimum conditions for concentration, temperature, and time were found to be 2.5%, 85 °C, and 50 min, respectively. The untreated ES (UES) and treated ES (TES) particles were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscope (SEM), particle size distribution, and contact angle. FTIR confirmed the chemical modification of SA on ES surface and DSC reflects an endothermic peak at 240 °C. XRD reveal a decrease in crystal size and crystallinity, while contact angle increases to 169° from 42°. The SEM observations clearly reflect a distinct decrease and separation of small domains of ES particles thus improving an increased surface area. Afterwards, the UES and TES particles were reinforced in epoxy at 15 and 20 weight (wt.) % loading. The tensile tests confirmed a 22% increase in elongation as compared to pure epoxy due to the hydrogen bonding between TES particles and matrix. The lowest brittleness was recorded for TES/epoxy composites on 20 wt % loading. The TGA confirmed the improved thermal stabilities at 20 wt % loading of TES particles in matrix, the improvements in T5%, T10%, and T20% values were recorded as 33, 26, and 21 °C higher than the corresponding values for neat matrix. The TES/epoxy composites on 20 wt % showed 41% increase in storage modulus as compared to the pristine epoxy, and cross-link density reaches to 2.71 × 10−3 from 1.29 × 10−3 mol/cm3 for neat matrix. The decline in tan δ height and improvement in Tg were also observed. The best adhesion effectiveness was recorded for TES/epoxy composites. This simple and economical modification technique can enhance the application of ES particles in various polymeric coating and composites applications.

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Ultrastructural and Physicochemical Characterization of a Non-Crosslinked Type 1 Bovine Derived Collagen Membrane

Polymers ◽

10.3390/polym13234135 ◽

2021 ◽

Vol 13 (23) ◽

pp. 4135

Author(s):

Igor da Silva Brum ◽

Carlos Nelson Elias ◽

Ana Lucia Rosa Nascimento ◽

Cherley Borba Vieira de Andrade ◽

Ronaldo Sergio de Biasi ◽

...

Keyword(s):

Electron Microscopy ◽

Contact Angle ◽

Physicochemical Characterization ◽

Tensile Tests ◽

Collagen Membrane ◽

Scanning Calorimetry ◽

Transmission Electron ◽

Collagen Membranes

In this work, in vitro testing was used to study the properties of non-crosslinked type 1 bovine derived collagen membranes used in bone regeneration surgery. Collagen membranes were prepared, their surface roughness was quantified by interferometry, their morphology was observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), their wettability was measured by the contact angle technique, their mechanical properties were investigated by tensile testing, their phase transformation temperatures were measured by Differential Scanning Calorimetry (DSC), and their biocompatibility was evaluated by immunological testing. The calorimetry tests showed that the membrane is formed only by type 1 collagen. The SEM observations showed that the morphology consists of layers of highly organized collagen fibers and patterns of striated fibrils typical of type 1 collagen. The small contact angle showed that the membrane is hydrophilic, with the possibility of rapid absorption of body fluids. The tensile tests showed that the membrane has enough elasticity, ductility, and mechanical strength for use in tissue regeneration. With the immunostaining technique, it was possible to confirm the membrane biocompatibility.

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Biodegradable and Toughened Composite of Poly(Propylene Carbonate)/Thermoplastic Polyurethane (PPC/TPU): Effect of Hydrogen Bonding

International Journal of Molecular Sciences ◽

10.3390/ijms19072032 ◽

2018 ◽

Vol 19 (7) ◽

pp. 2032 ◽

Cited By ~ 4

Author(s):

Dongmei Han ◽

Guiji Chen ◽

Min Xiao ◽

Shuanjin Wang ◽

Shou Chen ◽

...

Keyword(s):

Mechanical Properties ◽

Propylene Carbonate ◽

Thermoplastic Polyurethane ◽

Tensile Tests ◽

Mechanical Analysis ◽

Scanning Calorimetry ◽

Thermal Stabilities ◽

Dynamic Mechanical ◽

Brittle Ductile Transition ◽

Poly Propylene

The blends of Poly(propylene carbonate) (PPC) and polyester-based thermoplastic polyurethane (TPU) were melt compounded in an internal mixer. The compatibility, thermal behaviors, mechanical properties and toughening mechanism of the blends were investigated using Fourier transform infrared spectra (FTIR), tensile tests, impact tests, differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and dynamic mechanical analysis technologies. FTIR and SEM examination reveal strong interfacial adhesion between PPC matrix and suspended TPU particles. Dynamic mechanical analyzer (DMA) characterize the glass transition temperature, secondary motion and low temperature properties. By the incorporation of TPU, the thermal stabilities are greatly enhanced and the mechanical properties are obviously improved for the PPC/TPU blends. Moreover, PPC/TPU blends exhibit a brittle-ductile transition with the addition of 20 wt % TPU. It is considered that the enhanced toughness results in the shear yielding occurred in both PPC matrix and TPU particles of the blends.

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Wastes from Agricultural Silage Film Recycling Line as a Potential Polymer Materials

Polymers ◽

10.3390/polym13091383 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1383

Author(s):

Jerzy Korol ◽

Aleksander Hejna ◽

Klaudiusz Wypiór ◽

Krzysztof Mijalski ◽

Ewelina Chmielnicka

Keyword(s):

Vinyl Acetate ◽

Thermal Performance ◽

Mechanical Performance ◽

Ethylene Vinyl Acetate ◽

Tensile Tests ◽

Solid Particles ◽

Polymer Materials ◽

Slight Reduction ◽

Scanning Calorimetry ◽

Crystallinity Degree

The recycling of plastics is currently one of the most significant industrial challenges. Due to the enormous amounts of plastic wastes generated by various industry branches, it is essential to look for potential methods for their utilization. In the presented work, we investigated the recycling potential of wastes originated from the agricultural films recycling line. Their structure and properties were analyzed, and they were modified with 2.5 wt % of commercially available compatibilizers. The mechanical and thermal performance of modified wastes were evaluated by tensile tests, thermogravimetric analysis, and differential scanning calorimetry. It was found that incorporation of such a small amount of modifiers may overcome the drawbacks caused by the presence of impurities. The incorporation of maleic anhydride-grafted compounds enhanced the tensile strength of wastes by 13–25%. The use of more ductile compatibilizers—ethylene-vinyl acetate and paraffin increased the elongation at break by 55–64%. The presence of compatibilizers also reduced the stiffness of materials resulting from the presence of solid particles. It was particularly emphasized for styrene-ethylene-butadiene-styrene and ethylene-vinyl acetate copolymers, which caused up to a 20% drop of Young’s modulus. Such effects may facilitate the further applications of analyzed wastes, e.g., in polymer film production. Thermal performance was only slightly affected by compatibilization. It caused a slight reduction in polyethylene melting temperatures (up to 2.8 °C) and crystallinity degree (up to 16%). For more contaminated materials, the addition of compatibilizers caused a minor reduction in the decomposition onset (up to 6 °C). At the same time, for the waste after three washing cycles, thermal stability was improved. Moreover, depending on the desired properties and application, materials do not have to go through the whole recycling line, simplifying the process, reducing energy and water consumption. The presented results indicate that it is possible to efficiently use the materials, which do not have to undergo the whole recycling process. Despite the presence of impurities, they could be applied in the manufacturing of products which do not require exceptional mechanical performance.

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Characterization of Beeswax, Candelilla Wax and Paraffin Wax for Coating Cheeses

Coatings ◽

10.3390/coatings11030261 ◽

2021 ◽

Vol 11 (3) ◽

pp. 261

Author(s):

Adolfo Bucio ◽

Rosario Moreno-Tovar ◽

Lauro Bucio ◽

Jessica Espinosa-Dávila ◽

Francisco Anguebes-Franceschi

Keyword(s):

Physical And Mechanical Properties ◽

Tensile Tests ◽

Paraffin Wax ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Absorption Bands ◽

Dimensional Changes ◽

Ductile Behavior ◽

Candelilla Wax

A study on the physical and mechanical properties of beeswax (BW), candelilla wax (CW), paraffin wax (PW) and blends was carried out with the aim to evaluate their usefulness as coatings for cheeses. Waxes were analyzed by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), differential scanning calorimetry (DSC), permeability, viscosity, flexural and tensile tests and scanning electron microscopy. Cheeses were coated with the waxes and stored for 5 weeks at 30 °C. Measured parameters were weight, moisture, occurrence and degree of fractures, and dimensional changes. The crystal phases identified by XRD for the three waxes allowed them to determine the length of alkanes and the nonlinear compounds in crystallizable forms in waxes. FTIR spectra showed absorption bands between 1800 and 800 cm−1 related to carbonyls in BW and CW. In DSC, the onset of melting temperature was 45.5 °C for BW, and >54 °C for CW and PW. Cheeses coated with BW did not show cracks after storage. Cheeses coated with CW and PW showed microcraks, and lost weight, moisture and shrunk. In the flexural and tensile tests, BW was ductile; CW and PW were brittle. BW blends with CW or PW displays a semi ductile behavior. Cheeses coated with BW blends lost less than 5% weight during storage. The best waxes were BW and the blends.

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Effect of Nanofiller Content on Dynamic Mechanical and Thermal Properties of Multi-Walled Carbon Nanotube and Montmorillonite Nanoclay Filler Hybrid Shape Memory Epoxy Composites

Polymers ◽

10.3390/polym13050700 ◽

2021 ◽

Vol 13 (5) ◽

pp. 700

Author(s):

Muhamad Hasfanizam Mat Yazik ◽

Mohamed Thariq Hameed Sultan ◽

Mohammad Jawaid ◽

Abd Rahim Abu Talib ◽

Norkhairunnisa Mazlan ◽

...

Keyword(s):

Shape Memory ◽

High Performance ◽

Loss Modulus ◽

Decomposition Temperature ◽

Hybrid Nanocomposites ◽

Mechanical And Thermal Properties ◽

Scanning Calorimetry ◽

Hybrid Filler ◽

Dynamic Mechanical ◽

Tan Δ

The aim of the present study has been to evaluate the effect of hybridization of montmorillonite (MMT) and multi-walled carbon nanotubes (MWCNT) on the thermal and viscoelastic properties of shape memory epoxy polymer (SMEP) nanocomposites. In this study, ultra-sonication was utilized to disperse 1%, 3%, and 5% MMT in combination with 0.5%, 1%, and 1.5% MWCNT into the epoxy system. The fabricated SMEP hybrid nanocomposites were characterized via differential scanning calorimetry, dynamic mechanical analysis, and thermogravimetric analysis. The storage modulus (E’), loss modulus (E”), tan δ, decomposition temperature, and decomposition rate, varied upon the addition of the fillers. Tan δ indicated a reduction of glass transition temperature (Tg) for all the hybrid SMEP nanocomposites. 3% MMT/1% MWCNT displayed best overall performance compared to other hybrid filler concentrations and indicated a better mechanical property compared to neat SMEP. These findings open a way to develop novel high-performance composites for various potential applications, such as morphing structures and actuators, as well as biomedical devices.

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The Influence of the Addition of Nuts on the Thermal and Rheological Properties of Wheat Flour

Molecules ◽

10.3390/molecules26133969 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3969

Author(s):

Karolina Pycia ◽

Lesław Juszczak

Keyword(s):

Rheological Properties ◽

Wheat Flour ◽

Viscoelastic Properties ◽

Control Sample ◽

Scanning Calorimetry ◽

Creep And Recovery ◽

Research Material ◽

Pasting Characteristics ◽

Tan Δ ◽

Weak Gels

The aim of the study was to assess the influence of replacing wheat flour with hazelnuts or walnuts, in various amounts, on the thermal and rheological properties of the obtained systems. The research material were systems in which wheat flour was replaced with ground hazelnuts (H) or walnuts (W) in the amount of 5%, 10%, and 15%. The parameters of the thermodynamic gelatinization characteristics were determined by the differential scanning calorimetry method. In addition, the pasting characteristics were determined with the use of a viscosity analyzer and the viscoelastic properties were assessed. Sweep frequency and creep and recovery tests were used to assess the viscoelastic properties of the tested gels. It was found that replacing wheat flour with nuts increased the values of gelatinization temperature, gelatinization, and retrogradation enthalpy, and the degree of retrogradation. The highest viscosity was characteristic of the control sample (2039 mPa·s), and the lowest for the paste with 15% addition of walnuts (1120 mPa·s). Replacing the flour with nuts resulted in a very visible reduction in the viscosity of such systems. In addition, gels based on the systems with the addition of H and W were weak gels (tan δ = G″/G′ > 0.1), and the values of G′ and G″ parameters decreased with the increased share of nuts in the systems. Creep and recovery analysis indicated that the systems in which wheat flour was replaced with hazelnuts were less susceptible to deformation compared to the systems with the addition of W.

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Effect of toughened polyamide-coated carbon fiber fabric on the mechanical performance and fracture toughness of CFRP

Journal of Composite Materials ◽

10.1177/0021998321999458 ◽

2021 ◽

pp. 002199832199945

Author(s):

Jong H Eun ◽

Bo K Choi ◽

Sun M Sung ◽

Min S Kim ◽

Joon S Lee

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Photoelectron Spectroscopy ◽

Mechanical Performance ◽

Epoxy Composites ◽

Scanning Calorimetry ◽

Internal Damage ◽

Impact Tests ◽

Flexural Tests ◽

The Impact

In this study, carbon/epoxy composites were manufactured by coating with a polyamide at different weight percentages (5 wt.%, 10 wt.%, 15 wt.%, and 20 wt.%) to improve their impact resistance and fracture toughness. The chemical reaction between the polyamide and epoxy resin were examined by fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray photoelectron spectroscopy. The mechanical properties and fracture toughness of the carbon/epoxy composites were analyzed. The mechanical properties of the carbon/epoxy composites, such as transverse flexural tests, longitudinal flexural tests, and impact tests, were investigated. After the impact tests, an ultrasonic C-scan was performed to reveal the internal damage area. The interlaminar fracture toughness of the carbon/epoxy composites was measured using a mode I test. The critical energy release rates were increased by 77% compared to the virgin carbon/epoxy composites. The surface morphology of the fractured surface was observed. The toughening mechanism of the carbon/epoxy composites was suggested based on the confirmed experimental data.

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Metallization of Thermoplastic Polymers and Composites 3D Printed by Fused Filament Fabrication

Technologies ◽

10.3390/technologies9030049 ◽

2021 ◽

Vol 9 (3) ◽

pp. 49

Author(s):

Alessia Romani ◽

Andrea Mantelli ◽

Paolo Tralli ◽

Stefano Turri ◽

Marinella Levi ◽

...

Keyword(s):

Physical Vapor Deposition ◽

Test Sample ◽

Tensile Tests ◽

Layer By Layer ◽

Post Processing ◽

Thermoplastic Polymers ◽

Fused Filament Fabrication ◽

Scanning Calorimetry ◽

3D Printed ◽

Manufacturing Technologies

Fused filament fabrication allows the direct manufacturing of customized and complex products although the layer-by-layer appearance of this process strongly affects the surface quality of the final parts. In recent years, an increasing number of post-processing treatments has been developed for the most used materials. Contrarily to other additive manufacturing technologies, metallization is not a common surface treatment for this process despite the increasing range of high-performing 3D printable materials. The objective of this work is to explore the use of physical vapor deposition sputtering for the chromium metallization of thermoplastic polymers and composites obtained by fused filament fabrication. The thermal and mechanical properties of five materials were firstly evaluated by means of differential scanning calorimetry and tensile tests. Meanwhile, a specific finishing torture test sample was designed and 3D printed to perform the metallization process and evaluate the finishing on different geometrical features. Furthermore, the roughness of the samples was measured before and after the metallization, and a cost analysis was performed to assess the cost-efficiency. To sum up, the metallization of five samples made with different materials was successfully achieved. Although some 3D printing defects worsened after the post-processing treatment, good homogeneity on the finest details was reached. These promising results may encourage further experimentations as well as the development of new applications, i.e., for the automotive and furniture fields.

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Mechanical, Thermal and Rheological Properties of Polyethylene-Based Composites Filled with Micrometric Aluminum Powder

Materials ◽

10.3390/ma13051242 ◽

2020 ◽

Vol 13 (5) ◽

pp. 1242

Author(s):

Olga Mysiukiewicz ◽

Paulina Kosmela ◽

Mateusz Barczewski ◽

Aleksander Hejna

Keyword(s):

Mechanical Properties ◽

Melt Flow Index ◽

Tensile Tests ◽

Mechanical Analysis ◽

Flow Index ◽

Scanning Calorimetry ◽

Metal Composites ◽

Pre Treatment ◽

The Impact ◽

Properties Of Composites

Investigations related to polymer/metal composites are often limited to the analysis of the electrical and thermal conductivity of the materials. The presented study aims to analyze the impact of aluminum (Al) filler content (from 1 to 20 wt%) on the rarely investigated properties of composites based on the high-density polyethylene (HDPE) matrix. The crystalline structure, rheological (melt flow index and oscillatory rheometry), thermal (differential scanning calorimetry), as well as static (tensile tests, hardness, rebound resilience) and dynamic (dynamical mechanical analysis) mechanical properties of composites were investigated. The incorporation of 1 and 2 wt% of aluminum filler resulted in small enhancements of mechanical properties, while loadings of 5 and 10 wt% provided materials with a similar performance to neat HDPE. Such results were supported by the lack of disturbances in the rheological behavior of composites. The presented results indicate that a significant content of aluminum filler may be introduced into the HDPE matrix without additional pre-treatment and does not cause the deterioration of composites’ performance, which should be considered beneficial when engineering PE/metal composites.

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Effect of DMPA and Molecular Weight of Polyethylene Glycol on Water-Soluble Polyurethane

Polymers ◽

10.3390/polym11121915 ◽

2019 ◽

Vol 11 (12) ◽

pp. 1915 ◽

Cited By ~ 2

Author(s):

Eyob Wondu ◽

Hyun Woo Oh ◽

Jooheon Kim

Keyword(s):

Molecular Weight ◽

Contact Angle ◽

Polyethylene Glycol ◽

Photoelectron Spectroscopy ◽

Water Solubility ◽

Soft Segment ◽

Water Soluble ◽

Size Exclusion ◽

Resonance Spectroscopy ◽

Scanning Calorimetry

In this study water-soluble polyurethane (WSPU) was synthesized from isophorone diisocyanate (IPDI), and polyethylene glycol (PEG), 2-bis(hydroxymethyl) propionic acid or dimethylolpropionic acid (DMPA), butane-1,4-diol (BD), and triethylamine (TEA) using an acetone process. The water solubility was investigated by solubilizing the polymer in water and measuring the contact angle and the results indicated that water solubility and contact angle tendency were increased as the molecular weight of the soft segment decreased, the amount of emulsifier was increased, and soft segment to hard segment ratio was lower. The contact angle of samples without emulsifier was greater than 87°, while that of with emulsifier was less than 67°, indicating a shift from highly hydrophobic to hydrophilic. The WSPU was also analyzed using Fourier transform infrared spectroscopy (FT-IR) to identify the absorption of functional groups and further checked by X-ray photoelectron spectroscopy (XPS). The molecular weight of WSPU was measured using size-exclusion chromatography (SEC). The structure of the WSPU was confirmed by nuclear magnetic resonance spectroscopy (NMR). The thermal properties of WSPU were analyzed using thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC).

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