scholarly journals Density-Adjustable Bio-Based Polysulfide Composite Prepared by Inverse Vulcanization and Bio-Based Fillers

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2127
Author(s):  
Yanxia Liu ◽  
Yidan Chen ◽  
Yagang Zhang ◽  
Yurong Chen ◽  
Lulu Wang ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Petrochemical Industry ◽  
Cottonseed Oil ◽  
Chemical Structures ◽  
Global Problem ◽  
Different Types ◽  
Excess Sulfur

Excess sulfur has become a global problem in petrochemical industry. Inexpensive and easily available cottonseed oil (CSO) is still underutilized. To resolve these issues, bio-based polysulfide composites were prepared via inverse vulcanization of sulfur and CSO. The density of polysulfide composites was adjusted by fillers. The results showed that Elm and cattail as the fillers had no effects on the thermal properties and chemical structures of polysulfide composites. However, the morphologies of polysulfide composites were significantly influenced by the fillers. Different types and amounts of fillers produced significantly different holes and folds in the composites. The fillers were embedded in polysulfide composites by physical filling. This study provides an alternative and promising approach for preparing affordable density-adjustable bio-based polysulfide composite.

scholarly journals The Preparation, Thermal Properties, and Fire Property of a Phosphorus-Containing Flame-Retardant Styrene Copolymer

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 127 ◽  
Author(s):  
Yu Sun ◽  
Yazhen Wang ◽  
Li Liu ◽  
Tianyuan Xiao
Keyword(s):  
Thermal Properties ◽  
Thermogravimetric Analysis ◽  
Flame Retardant ◽  
Oxygen Index ◽  
Limiting Oxygen Index ◽  
Chemical Structures ◽  
1H Nuclear Magnetic Resonance ◽  
Phosphorus Containing ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

A 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) acrylate, (6-oxidodibenzo [c,e][1,2] oxaphosphinin-6-yl) methyl acrylate (DOPOAA), has been prepared. Copolymers of styrene (St) and DOPOAA were prepared by emulsion polymerization. The chemical structures of copolymers containing levels of DOPOAA were verified using Fourier transform infrared (FT-IR) spectroscopy and 1H nuclear magnetic resonance (1H-NMR) spectroscopy. The thermal properties and flame-retardant behaviors of DOPO-containing monomers and copolymers were observed using thermogravimetric analysis and micro calorimetry tests. From thermogravimetric analysis (TGA), it was found out that the T5% for decomposition of the copolymer was lower than that of polystyrene (PS), but the residue at 700 °C was higher than that of PS. The results from micro calorimetry (MCC) tests indicated that the rate for the heat release of the copolymer combustion was lower than that for PS. The limiting oxygen index (LOI) for combustion of the copolymer rose with increasing levels of DOPOAA. These data indicate that copolymerization of the phosphorus-containing flame-retardant monomer, DOPOAA, into a PS segment can effectively improve the thermal stability and flame retardancy of the copolymer.

Thermal properties of polybenzoxazine exhibiting improved toughness: Blending with cyclodextrin and its derivatives

2021 ◽  
pp. 095400832110130
Author(s):  
Hailong Li ◽  
Sipei Zhao ◽  
Li Pei ◽  
Zihe Qiao ◽  
Ding Han ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Hydrogen Bonds ◽  
High Performance ◽  
Practical Application ◽  
Scanning Calorimetry ◽  
Thermoset Resins ◽  
Chemical Structures ◽  
Microscopy Techniques ◽  
Fractured Surface ◽  
Scanning Electron

Polybenzoxazines are emerging as a class of high-performance thermoset polymers that can find their applications in various fields. However, its practical application is limited by its low toughness. The cyclic β-cyclodextrin and a newly synthesized derivative (β-cyclodextrin-MAH) were separately blended with benzoxazine to improve the toughness of polybenzoxazine. The results revealed that the maximum impact strength of the blend was 12.24 kJ·m−2 and 14.29 kJ·m−2 when 1 wt.% of β-Cyclodextrin and β-Cyclodextrin-MAH, respectively, were used. The strengths were 53% and 86% higher than that of pure polybenzoxazine. The curing reaction, possible chemical structures, and fractured surface were examined using differential scanning calorimetry, Fourier transform infrared spectroscopy, and scanning electron microscopy techniques to understand the mechanism of generation of toughness. The results revealed that the sea-island structure and the presence of hydrogen bonds between polybenzoxazine and β-cyclodextrin and β-cyclodextrin-MAH resulted in the generation of toughness. Furthermore, the curves generated during thermogravimetric analysis did not significantly change, revealing the good thermal properties of the system. The phase-separated structure and the hydrogen bonds present in the system can be exploited to prepare synergistically tough polybenzoxazine exhibiting excellent thermal properties. This can be a potential way of modifying the thermoset resins.

scholarly journals Influence of partial replacement of sand with copper slag on the thermal properties of hardened concrete

2019 ◽  
Author(s):  
Łukasz Majewski ◽  
Roman Jaskulski ◽  
Wojciech Kubissa
Keyword(s):  
Thermal Properties ◽  
Cement Content ◽  
Copper Slag ◽  
Partial Replacement ◽  
Hardened Concrete ◽  
Different Types ◽  
Compressive Strength Of Concrete ◽  
The Impact ◽  
Fine Copper ◽  
Slag Waste

The article presents the results of testing the effect of partial replacement of sand with fine copper slag waste on the thermal properties of hardened concrete. The impact of the replacement on mechanical properties (ie. compressive and tensile strength of concrete) was also investigated. The thermal properties of the concrete were determined using the non-stationary method with the ISOMET 2114 device. Tests were performed on concrete containing three different types of cement (CEM I, CEM II and CEM III). A total cement content of 360 kg/m3 was assumed in the compositions of all concrete mixes with a water-cement ratio of 0.45. Replacing 66% of the sand volume with copper slag waste caused a decrease in thermal conductivity by about 4–8% in relation to the reference concrete. In addition, the compressive strength of concrete containing copper slag increased by about from 4–21% in relation to the reference concrete.

scholarly journals Analysis of Bio-Based Fatty Esters PCM’s Thermal Properties and Investigation of Trends in Relation to Chemical Structures

2019 ◽  
Vol 9 (2) ◽  
pp. 225 ◽  
Author(s):  
Rebecca Ravotti ◽  
Oliver Fellmann ◽  
Nicolas Lardon ◽  
Ludger Fischer ◽  
Anastasia Stamatiou ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Phase Change ◽  
Energy Demand ◽  
Phase Change Materials ◽  
Arachidic Acid ◽  
Resonance Spectroscopy ◽  
Scanning Calorimetry ◽  
Fatty Esters ◽  
Latent Heat Storage ◽  
Chemical Structures

As global energy demand increases while primary sources and fossil fuels’ availability decrease, research has shifted its focus to thermal energy storage systems as alternative technologies able to cover for the mismatch between demand and supply. Among the different phase change materials available, esters possess particularly favorable properties with reported high enthalpies of fusion, low corrosivity, low toxicity, low supercooling, thermal and chemical stability as well as biodegradability and being derived from renewable feedstock. Despite such advantages, little to no data on the thermal behavior of esters is available due to low commercial availability. This study constitutes a continuation of previous works from the authors on the investigation of fatty esters as novel phase change materials. Here, methyl, pentyl and decyl esters of arachidic acid, and pentyl esters of myristic, palmitic, stearic and behenic acid are synthesized through Fischer esterification with high purities and their properties are studied. The chemical structures and purities are confirmed through Attenuated Total Reflectance Infrared Spectroscopy, Gas Chromatography coupled with Mass Spectroscopy and Nuclear Magnetic Resonance Spectroscopy, while the determination of the thermal properties is performed through Differential Scanning Calorimetry and Thermogravimetric Analysis. In conclusion, some correlations between the melting temperatures and the chemical structures are discovered, and the fatty esters are assessed based on their suitability as phase change materials for latent heat storage applications.

<i>Physicochemical, pasting and thermal properties of different types of starch</i>

2020 ◽  
Author(s):  
Olufemi Adeyemi Adetola ◽  
Ayoola Patrick Olalusi ◽  
Akinbode A. Adedeji
Keyword(s):  
Thermal Properties ◽  
Different Types

scholarly journals The Utilization of Recycled Masonry Aggregate and Recycled EPS for Concrete Blocks for Mortarless Masonry

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1923 ◽  
Author(s):  
Tereza Pavlu ◽  
Kristina Fortova ◽  
Jakub Divis ◽  
Petr Hajek
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Masonry Wall ◽  
Expanded Polystyrene ◽  
Mechanical And Thermal Properties ◽  
Concrete Mixtures ◽  
Wall Structures ◽  
Different Types ◽  
Concrete Blocks ◽  
Recycled Masonry

The main aim of this paper is to carry out the environmentally based enhancement of a concrete mixture containing recycled materials whilst considering natural resource consumption as well as mechanical and thermal property levels. The developed concrete is intended to be used in mortarless masonry wall structures. Ten concrete mixtures with different types and replacement rates of recycled masonry aggregate and recycled expanded polystyrene were prepared, and their mechanical and thermal properties were experimentally investigated. It was found that the use of recycled masonry aggregate led to better thermal properties while maintaining sufficient mechanical properties. On the contrary, the addition of recycled expanded polystyrene did not significantly affect the thermal properties of concrete, but the mechanical properties considerably declined. For this reason, the recycled masonry aggregate is suitable to use as an aggregate for concrete masonry blocks for wall structures.

Preparation, characterisation, and dielectric properties of polypyrrole-clay composites

2013 ◽  
Vol 67 (8) ◽  
Author(s):  
Seyfullah Madakbaş ◽  
Emrah Çakmakçı ◽  
Memet Kahraman ◽  
Kadir Esmer
Keyword(s):  
Glass Transition ◽  
Thermal Properties ◽  
Clay Content ◽  
Xrd Analysis ◽  
Glass Transition Temperatures ◽  
Chemical Structures ◽  
Dsc Measurements ◽  
Tga And Dsc ◽  
Dielectric Conductivity

AbstractIn this study, polypyrrole-clay (PPy-clay) composites were prepared by the in situ chemical oxidative polymerisation of pyrrole in the presence of clay. The chemical structures of the composites were characterised by FTIR and XRD analysis. The thermal properties of these novel composites were analysed by TGA and DSC measurements. Glass-transition temperatures and char yields increased with the increase in clay content in the nanocomposites. The interactions between PPy and clay were mainly between polypyrrole and the layers of clay. It was observed that, as the amount of clay in the composites increased, the dielectric permittivity decreased while the dielectric conductivity of the composite materials increased.

Study on Flexible Fatigue Properties of Nature Rubber with Different Styrene-Butadiene Rubber

2016 ◽  
Vol 717 ◽  
pp. 57-61
Author(s):  
Wei Liu ◽  
Zhong Cun Bao ◽  
Cheng Zhong Zong
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Service Life ◽  
Special Structure ◽  
Fatigue Properties ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Vulcanized Rubber ◽  
Different Types ◽  
Styrene Butadiene

Flexible fatigue properties is an important property of rubber, it can reflect the service life of rubber products. Different types of SSBR were used in the vulcanized rubber with NR contributed different to the flexible fatigue properties. In this paper, 5 different types of SSBR with special structure were used to study the mechanical properties, thermal properties and the flexible fatigue properties. In a result, with different types SSBR, the vulcanized rubber show different basic mechanical properties and flexible fatigue properties, but little effect to the hardness and stretching stress. Above all these SSBR, RC2564S is the best which contribute to flexible fatigue properties.

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