Study of Processing and Properties of a few Hemp Linter Fiber Reinforced Polylactic Acids Composite Materials

2011 ◽  
Vol 332-334 ◽  
pp. 1785-1789
Author(s):  
Jia Shuang Luan ◽  
Mei Zhang ◽  
Fu Gui Zhou ◽  
Yang Wang ◽  
Gang Ma ◽  
...  
Keyword(s):  
Thermogravimetric Analysis ◽  
Mechanical Performance ◽  
Average Molecular Weight ◽  
Degradation Process ◽  
Mechanical Tests ◽  
Scanning Calorimetry ◽  
Hemp Fiber ◽  
Batch Mixing ◽  
Sample Count ◽  
Poly Ethylene

Composites of poly(L-lactide) (PLA) with hemp linter fibers, prepared by batch mixing and plasticized with poly(ethylene glycol) (PEG; weight-average molecular weight 1000 g/mol), were examined by differential scanning calorimetry, thermogravimetric analysis, and mechanical tests. The properties of samples of PLA/hemp and PLA–PEG/hemp composites were analyzed as a function of the fiber amount. The thermogravimetric analysis of the composites, carried out in air, showed that the degradation process of fiber-filled systems started earlier than that of plain PLA, independently of the presence of the plasticizer. Mechanical tests showed that the property of the composites have been enhanced increased with the hemp content. The mechanical performance high-point of composites appear with count of hemp linter fiber at 1%.(sample count of hemp fiber form 1% to 7%). Plasticization with PEG did not improve the tensile properties of the composites, but improve its break stress.

Adhesives for increasing the bonding strength of in situ manufactured metal-composite joints

2020 ◽  
pp. 095440702096575
Author(s):  
Robert Thomas ◽  
Fabian Fischer ◽  
Maik Gude
Keyword(s):  
Bonding Strength ◽  
Elevated Temperatures ◽  
Mechanical Performance ◽  
Storage Conditions ◽  
Mechanical Tests ◽  
Metal Composite ◽  
Scanning Calorimetry ◽  
Lap Shear ◽  
Glass Fibre Reinforced ◽  
Metallic Parts

In this present work, the potential of metallic parts, locally reinforced with a continuous glass fibre reinforced thermoset material, pre-impregnated with an epoxy matrix (prepreg), was evaluated by differential scanning calorimetry (DSC), single-lap shear tests and 3-point bending tests of a metal-composite hybrid hat profile. This technology is evaluated regarding an automotive use case, the DSC experiments in combination with moulding trials have proven curing times below 30 s for a moulding temperature of 180°C. A bonding strength of 13.5 MPa was characterized for a co-cured fibre-reinforced plastic (frp) onto a metallic joining partner. By additionally introducing an epoxy glue film as a bonding agent, which is co-cured together with the frp, the bonding strength can be increased significantly up to 25.4 MPa at the expense of the curing time. The mechanical tests on the hybrid hat profile have shown an increase of energy absorption compared with non-reinforced hat profiles. Here, also an additional glue film extends the performance regarding a co-cured plastic reinforcement without glue film. The influence of the storage conditions of the uncured prepreg materials on the mechanical performance was evaluated by a simulated physical ageing at elevated temperatures, followed by a mechanical characterization of the bonding strength and part performance. Also the effect of different testing temperatures and testing velocities on the capability of the metal-composite hybrid part is illustrated.

Influence of Transesterification on the Properties of PET/MAPE Blends Prepared by Reactive Extrusion

2011 ◽  
Vol 221 ◽  
pp. 43-47 ◽  
Author(s):  
Li Gong ◽  
Qing Wen Wang ◽  
Yong Ming Song ◽  
Hai Gang Wang ◽  
Shu Juan Sui ◽  
...  
Keyword(s):  
Reactive Extrusion ◽  
Mechanical Tests ◽  
Melt Crystallization ◽  
Scanning Calorimetry ◽  
Poly Ethylene Terephthalate ◽  
Sem Micrograph ◽  
Higher Temperature ◽  
Poly Ethylene ◽  
Transesterification Catalyst ◽  
The Impact

Blends based on maleic anhydride grafted polyethylene (MAPE) and poly(ethylene terephthalate)(PET) were prepared through reactive extrusion in the presence of titanium tetrabutoxide (Ti(OBu)4) as transesterification catalyst. Mechanical properties of PET/MAPE blends(70wt./30wt.) were evaluated by mechanical tests. The Effects of Ti(OBu)4 on the structure and melt crystallization behavior of the blends were investigated by Fourier transform infrared spectroscopy(FTIR), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The addition of Ti(OBu)4 to the blends could improve the compatibility between PET and MAPE as was evidenced by the SEM micrograph in which filaments connected to a network structure was observed. With increasing the contents of Ti(OBu)4, the impact strength of the blends increased obviously, the flexural strength and tensile strength of blends did not change significantly, while the degradation of PET was gradually significant as was evidenced by FTIR analysis. Small amount of Ti(OBu)4 could hinder the crystallization of PET and make its melt peak shifted to higher temperature.

scholarly journals The Thermal and Mechanical Properties of Poly(ethylene-co-vinyl acetate) Random Copolymers (PEVA) and its Covalently Crosslinked Analogues (cPEVA)

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1055 ◽  
Author(s):  
Ke Wang ◽  
Qibo Deng
Keyword(s):  
Mechanical Properties ◽  
Thermogravimetric Analysis ◽  
Vinyl Acetate ◽  
Polymer Networks ◽  
Crosslinking Density ◽  
Random Copolymers ◽  
Melting Transition ◽  
Thermal And Mechanical Properties ◽  
Scanning Calorimetry ◽  
Poly Ethylene

The thermal and mechanical properties of poly(ethylene-co-vinyl acetate) random copolymers (PEVA) and its covalently crosslinked analogues (cPEVA) were controlled by the overall crystallinity of the polymer networks. The cPEVAs with different VA-content were synthesized by thermally-induced crosslinking of linear PEVA with dicumyl peroxide (DCP). This work was mainly concerned with the effect of vinyl acetate (VA) content on the crosslinking density, thermal and mechanical properties of PEVAs and cPEVAs, respectively. The chemical composition was analyzed by thermogravimetric analysis and 1H-NMR. The thermal and mechanical properties of PEVAs and cPEVAs have been studied through a series of conventional analytical methods, including gel content determination, different scanning calorimetry, thermogravimetric analysis, dynamic mechanical thermal analysis and traditional mechanical measurements. The experimental results show that the thermal and mechanical properties of PEVAs and cPEVAs increase with decreasing the VA-content. A broad melting transition with a ΔTm in the range from 78 °C to 95 °C was observed for all polymer networks.

scholarly journals On the Use of Paper Sludge as Filler in Biocomposites for Injection Moulding

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2688
Author(s):  
Vito Gigante ◽  
Patrizia Cinelli ◽  
Marco Sandroni ◽  
Roberto D’ambrosio ◽  
Andrea Lazzeri ◽  
...  
Keyword(s):  
Injection Moulding ◽  
Mechanical Performance ◽  
Impact Resistance ◽  
Mechanical Tests ◽  
Lepidium Sativum ◽  
Poly Lactic Acid ◽  
Paper Sludge ◽  
Scanning Calorimetry ◽  
Twin Screw ◽  
Acetyl Tributyl Citrate

The potential use of paper sludge (PS) as filler in the production of bio-composites based on poly lactic acid (PLA) and polybutylene adipate terephthalate (PBAT) was investigated. PS/PLA/PBAT composites, with addition of acetyl tributyl citrate (ATBC) as biobased plasticizer, were produced with PS loadings up to 30 wt.% by twin-screw extrusion followed by injection moulding. The composites were characterized by rheological measurements, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and mechanical tests (tensile and impact resistance) to study the effect of PS on the processability, thermal stability, crystallinity and mechanical performance of polymeric matrix. The optimized composites at higher PS content were successfully processed to produce pots for horticulture and, in view of this application, preliminary phytotoxicity tests were conducted using the germination test on Lepidium sativum L. seeds. Results revealed that developed composites up to 30 wt.% PS had good processability by extrusion and injection moulding showing that PS is a potential substitute of calcium carbonate as filler in the production of bio-composites, and the absence of phytotoxic effects showed the possibility of their use in the production of pots/items for applications in floriculture and/or horticulture.

Effect of Sn Component Surface Finish on 92.5Pb-5Sn-2.5Ag

2014 ◽  
Vol 2014 (HITEC) ◽  
pp. 000364-000371
Author(s):  
Harry Schoeller ◽  
Martin Anselm ◽  
Imran Khan ◽  
Eric Cotts
Keyword(s):  
High Temperature ◽  
Mechanical Behavior ◽  
Surface Finish ◽  
Solder Joints ◽  
Mechanical Performance ◽  
Mechanical Tests ◽  
Fatigue Tests ◽  
Scanning Calorimetry ◽  
Microstructure Evaluation ◽  
Final Composition

This work investigates the effect of Sn component surface finish on the melting temperature, microstructure, and mechanical behavior of 92.5Pb-5Sn-2.5Ag. 92.5Pb-5Sn-2.5Ag was doped with up to 7% Sn to simulate the final composition of a joint after reflow with a component having Sn surface finish. Differential Scanning Calorimetry (DSC) was used to measure the change in matrix liquidus temperature with increasing Sn concentration. Microstructure evaluation and mechanical tests were carried out on 20 mil solder spheres reflowed on high temperature polyimide test coupons. Solder joints of each composition were cross-sectioned to examine the microstructure. The area fraction of β-Sn and Ag3Sn was quantified for each composition using image analysis software. Shear and isothermal fatigue tests of individual solder joints with varying Sn concentrations were conducted at room temperature. Joints were also sheared at 200°C after aging for 1024hrs at 200°C to simulate a downhole environment. The failed interfaces were examined to determine the mode of failure. Beyond providing guidance for surface finish selection, this work examines the microstructure and mechanical behavior of 92.5Pb-5Sn-2.5Ag as a function of Sn concentration and temperature. An understanding of the microstructure-mechanical performance relationship will aid in the development of new alloys for high temperature applications.

The Structure of Radiation Cross-Linked Poly (ethylene oxide) Gels

1971 ◽  
Vol 29 ◽  
pp. 76-77
Author(s):  
C. E. Cluthe ◽  
G. G. Cocks
Keyword(s):  
Molecular Weight ◽  
Ethylene Oxide ◽  
Parallel Plate ◽  
Average Molecular Weight ◽  
Radical Reaction ◽  
Free Radical Reaction ◽  
Nitrogen Gas ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Initial Viscosity

Aqueous solutions of a 1 weight-per cent poly (ethylene oxide) (PEO) were degassed under vacuum, transferred to a parallel plate viscometer under a nitrogen gas blanket, and exposed to Co60 gamma radiation. The Co60 source was rated at 4000 curies, and the dose ratewas 3.8x105 rads/hr. The poly (ethylene oxide) employed in the irradiations had an initial viscosity average molecular weight of 2.1 x 106.The solutions were gelled by a free radical reaction with dosages ranging from 5x104 rads to 4.8x106 rads.

Thermal Stability of N-Heterocycle-Stabilized Iodanes – A Systematic Investigation

2019 ◽  
Author(s):  
Andreas Boelke ◽  
Yulia A. Vlasenko ◽  
Mekhman S. Yusubov ◽  
Boris Nachtsheim ◽  
Pavel Postnikov
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Systematic Investigation ◽  
Scanning Calorimetry ◽  
Thermal Stability Of

<p>The thermal stability of pseudocyclic and cyclic <i>N</i>-heterocycle-stabilized (hydroxy)aryl- and mesityl(aryl)-l<sup>3</sup>-iodanes (NHIs) through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is investigated. NHIs bearing <i>N</i>-heterocycles with a high N/C-ratio such as triazoles show among the lowest descomposition temperatures and the highest decomposition energies. A comparison of NHIs with known (pseudo)cyclic benziodoxolones is made and we further correlated their thermal stability with reactivity in a model oxygenation. </p>

Plant Oil-Based Nanoemulsions: Preparation and Efficacy for Hair Treatment

2020 ◽  
Vol 04 ◽  
Author(s):  
Lívia Gonçalves Ferreira Rodrigues ◽  
Juliana Falcão Alves de Carvalho ◽  
Cristal dos Santos Cerqueira Pinto ◽  
Elisabete Pereira Santos ◽  
Claudia Regina Elias Mansur
Keyword(s):  
Human Hair ◽  
Mechanical Tests ◽  
Plant Oils ◽  
Plant Oil ◽  
Oil In Water ◽  
Hair Samples ◽  
Poly Ethylene Oxide ◽  
Treatment Objective ◽  
Poly Ethylene ◽  
Average Size

Background:: The use of polymers in hair care products is widespread, and silicones in particular are extensively used in cosmetic formulations. In addition, plant oils can also be used for hair treatment. Objective: In the present work, oil-in-water (O/W) nanoemulsions were prepared to repair chemical damage to human hair samples, to investigate the combined use of a silicone polyether copolymer (surfactant) that has a branch composed of poly(ethylene oxide) in its chains, and two types of plant oils: coconut and ojon oil. Materials and Methods:: Surfactant-oil-water formulations were obtained by ultrasonic processing. The nanoemulsions were then applied to human hair strands previously damaged with sodium hydroxide, to compare the treated strands with untreated ones. The efficacy of the formulations was investigated by scanning electron microscopy, thermogravimetric analysis and mechanical tests. Results and Discussion:: Stables nanoemulsions were obtained with average size of the dispersed droplets up to 400 nm. The micrographs suggest that the action mechanism of the nanoemulsions depends not only on the type of plant oil used and size of the droplets dispersed in the system, but also on the type of hair that receives the treatment. The thermal analysis showed that the use of nanoemulsion changed the temperature of keratin interconversion to higher values, which can make hair fibers more resistant to heat. Hair resistance was improved when comparing virgin samples to the damaged ones. Conclusion:: The nanoemulsions were efficient in the treatment of the hair samples, which showed a significant improvement of their mechanical properties.

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

Polymers ◽  
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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