scholarly journals Influence of synthesis conditions on molecular weight as well as mechanical and thermal properties of poly(hexamethylene 2,5-furanate)

Polimery ◽  
2021 ◽  
Vol 66 (10) ◽  
Author(s):  
Sandra Paszkiewicz ◽  
Izabela Irska ◽  
Konrad Walkowiak ◽  
Agata Zubkiewicz
Keyword(s):  
Molecular Weight ◽  
Thermal Properties ◽  
Phase Changes ◽  
Polymer Chains ◽  
Synthesis Process ◽  
Mechanical And Thermal Properties ◽  
Synthesis Conditions ◽  
Melt Polycondensation ◽  
The Relationship ◽  
Selection Of

Poly(hexamethylene 2,5-furanate) (PHF) was obtained by melt polycondensation. The process was carried out at temperatures of 230, 235 and 240 ° C. It has been shown that the selection of the optimal parameters of the synthesis process leads to the obtaining of  biomaterials of high molecular weight, and thus better mechanical and thermal properties. The relationship between the molecular weight and the mobility of polymer chains, and consequently the temperature of phase changes and mechanical properties, was determined.

Graft modification in bamboo cellulose nanofibrils: An effective option to improve compatibility and tunable surface energy

2021 ◽  
Author(s):  
Carlos Alejandro Rodríguez-Ramírez ◽  
Alain Dufresne ◽  
Norma Beatriz D'Accorso ◽  
Nancy Garcia
Keyword(s):  
Molecular Weight ◽  
Thermal Properties ◽  
Cellulose Nanofibrils ◽  
Value Added ◽  
Xrd Analysis ◽  
Low Molecular Weight ◽  
Mechanical And Thermal Properties ◽  
Graft Modification ◽  
Effective Option ◽  
20 Nm

Abstract In this work, from an endemic and non-significant value-added bamboo argentine, nanofibrils (CNFs) of 20 nm in width were obtained. These nanofibrils were chemical modified in surface with three simple steps using a noncommercial low molecular weight polylactic acid. The success of modification was confirmed by FTIR, TGA, DSC and XRD analysis. The modified nanofibrils were taken up for changing surface properties in films based on commercial PLA. The results show that dispersive (γ D/S) component of films increase of 34.7 mN/m to 36.1 mN/m after the addition of modified nanofibrils from 2 to 5% in formulation of the films, comparing with a physical blend. Interesting others result in physical, mechanical, and thermal properties of the nanocomposites, were reported.

Nanomaterials and Nanocomposites Thermal and Mechanical Properties Modelling

2019 ◽  
pp. 234-256 ◽  
Author(s):  
Siddhartha Kosti
Keyword(s):  
Thermal Properties ◽  
Structural Properties ◽  
Base Material ◽  
High Strength ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
Weight Percentage ◽  
Structural Applications ◽  
Glass Frp ◽  
Selection Of

This chapter deals with the modelling of nanomaterial and nanocomposite mechanical and thermal properties. Enrichment in the technology requires materials having higher thermal properties or higher structural properties. Nanomaterials and nanocomposites can serve this purpose accurately for aerospace or thermal applications and structural applications respectively. The thermal system requires materials having high thermal conductivity while structural system requires materials having high strength. Selection of the material for particular application is very critical and requires knowledge and experience. Al, Cu, TiO2, Al2O3, etc. are considered for thermal applications while epoxy-glass, FRP, etc. are considered for structural applications. Modelling of these nanomaterials and nanocomposites is done with the help of different mathematical models available in the literature. Results show that addition of the nanoparticle/composite in the base material can enhance the thermal and structural properties. Results also show that amount of weight percentage added also affects the properties.

Nanomaterials and Nanocomposites Thermal and Mechanical Properties Modelling

2021 ◽  
pp. 180-199
Author(s):  
Siddhartha Kosti
Keyword(s):  
Thermal Properties ◽  
Structural Properties ◽  
Base Material ◽  
High Strength ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
Weight Percentage ◽  
Structural Applications ◽  
Glass Frp ◽  
Selection Of

This chapter deals with the modelling of nanomaterial and nanocomposite mechanical and thermal properties. Enrichment in the technology requires materials having higher thermal properties or higher structural properties. Nanomaterials and nanocomposites can serve this purpose accurately for aerospace or thermal applications and structural applications respectively. The thermal system requires materials having high thermal conductivity while structural system requires materials having high strength. Selection of the material for particular application is very critical and requires knowledge and experience. Al, Cu, TiO2, Al2O3, etc. are considered for thermal applications while epoxy-glass, FRP, etc. are considered for structural applications. Modelling of these nanomaterials and nanocomposites is done with the help of different mathematical models available in the literature. Results show that addition of the nanoparticle/composite in the base material can enhance the thermal and structural properties. Results also show that amount of weight percentage added also affects the properties.

Mechanical and thermal properties of graphene oxide/ultrahigh molecular weight polyethylene nanocomposites

RSC Advances ◽  
2015 ◽  
Vol 5 (77) ◽  
pp. 63063-63072 ◽  
Author(s):  
Wenchao Pang ◽  
Zifeng Ni ◽  
Guomei Chen ◽  
Guodong Huang ◽  
Huadong Huang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Graphene Oxide ◽  
Thermal Properties ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Mechanical And Thermal Properties ◽  
Hummers Method ◽  
Ultrahigh Molecular Weight ◽  
Uhmwpe Composites ◽  
Modified Hummers Method

Graphene oxide (GO) was prepared according to a modified Hummers method, and a range of GO/ultrahigh molecular weight polyethylene (UHMWPE) composites were fabricated then their mechanical and thermal properties were investigated.

scholarly journals Micro and nanocomposites of polybutadienebased polyurethane liners with mineral fillers and nanoclay: thermal and mechanical properties

2017 ◽  
Vol 15 (1) ◽  
pp. 46-52 ◽  
Author(s):  
Pablo Ross ◽  
Germán Escobar ◽  
Guillermo Sevilla ◽  
Javier Quagliano
Keyword(s):  
Thermal Properties ◽  
Polymer Chains ◽  
Toluene Diisocyanate ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mineral Fillers

AbstractMicro and nanocomposites of hydroxyl terminated polybutadiene (HTPB)-based polyurethanes (NPU) were obtained using five mineral fillers and Cloisite 20A nanoclay, respectively. Samples were prepared by the reaction of HTPB polyol and toluene diisocyanate (TDI), and the chain was further extended with glyceryl monoricinoleate to produce the final elastomeric polyurethanes. Mechanical and thermal properties were studied, showing that mineral fillers (20%w/w) significantly increased tensile strength, in particular nanoclay (at 5% w/w). When nanoclay-polymer dispersion was modified with a silane and hydantoin-bond promoter, elongation at break was significantly increased with respect to NPU with C20A. Thermal properties measured by differential scanning calorimetry (DSC) were not significantly affected in any case. The molecular structure of prepared micro and nanocomposites was confirmed by Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. Interaction of fillers with polymer chains is discussed, considering the role of silanes in compatibilization of hydrophilic mineral fillers and hydrophobic polymer. The functionalization of nanoclay with HMDS silane was confirmed using FTIR. Microstructure of NPU with C20A nanoclay was confirmed by Atomic Force Microscopy (AFM).

Effect of chain extender on the mechanical and thermal resistance properties of polyurethane liners for composite propellants

Polyurethanes ◽  
2016 ◽  
Vol 1 (1) ◽  
Author(s):  
P. Ross ◽  
G. Sevilla ◽  
J. Quagliano
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Chain Extender ◽  
Molecular Structures ◽  
Polymer Chains ◽  
Mechanical And Thermal Properties ◽  
Thermal Changes ◽  
Ft Ir ◽  
Chain Lengths

AbstractPolyurethane formulations utilized as liners for composite propellants were prepared by the reaction of toluene-2,4-diisocyanate (TDI) and isophorone diisocyanate (IPDI) with hydroxyl terminated polybutadiene (HTPB), while polymer chains were further extended with neopentyl glycol diol, NPG triol and two different triols (monoglyceryl ricinoleate, MRG and trimethylolpropane, TMP). Liners were formulated with micronized titanium dioxide mechanically dispersed in hydroxyl-terminated polybutadiene (HTPB). The molecular structures of liners were confirmed by FT-IR. Thermal properties indicated that the nature of chain extender (crosslinker) only slightly affected the temperatures for decomposition of liners. Two main thermal changes were found at 370∘C and another at around 440–500∘C, depending on the chain extender utilized. On the other side, mechanical properties varied within the range of 0,7-1,8 MPa, consistent with this kind of elastomers. Tensile strength at break was only significantly affected with TMP and MRG-chain extended liners at the lowest concentrations tested of 1,3 and 2% (w/w), respectively. However, the behaviour depended on whether TDI or IPDI isocyanate was utilized for curing. TMP 1,3% crosslinked liner cured with TDI had a tensile strength of 1,82MPa whileMRG-crosslinked liner cured with IPDI had a tensile strength of 1,56 MPa. It was observed that at the higher NCO/OH ratios essayed, tensile strength and hardness increased, improving mechanical properties. Our results confirmed that TMP and MRG triols together with NPG diols can be used to tailor mechanical and thermal properties of liners, considering their different hydroxyl functionalities and chain lengths.

Preparation and Morphology of CdZnS Thin Films

2019 ◽  
Vol 18 (03n04) ◽  
pp. 1940060
Author(s):  
S. I. Sadovnikov
Keyword(s):  
Thin Films ◽  
Text Structure ◽  
Layer By Layer ◽  
Space Group ◽  
Synthesis Conditions ◽  
Layer Deposition ◽  
Two Phases ◽  
The Relationship ◽  
Selection Of ◽  
Deposition Conditions

Thin films based on limited solid solutions of cadmium and zinc sulfides have been synthesized by a one-stage epitaxial layer-by-layer deposition from an ammonium-containing aqueous solution of cadmium and zinc chlorides and thiocarbamide on a glass substrate. The thickness control of sulfide layers was carried out by selection of reagent concentrations and the deposition conditions. The relationship between the synthesis conditions of CdxZn[Formula: see text]S thin films and the size of sulfide nanoparticles in these films is established. The films contain two phases: hexagonal (space group [Formula: see text]) phase with [Formula: see text] structure of wurtzite type and cubic (space group [Formula: see text]-[Formula: see text]) phase with [Formula: see text] structure of sphalerite type. It is shown that the CdxZn[Formula: see text]S film consists of separate [Formula: see text][Formula: see text]nm agglomerates which are a collection of smaller nanometer-sized particles. The dependence of the band gap of the synthesized films on their thickness is found.

New sulfur-containing polymeric sorbents based on 2,2′-thiobisethanol dimethacrylate

2019 ◽  
Vol 91 (3) ◽  
pp. 409-420 ◽  
Author(s):  
Sylwia Ronka
Keyword(s):  
Metal Ions ◽  
Methylene Chloride ◽  
Suspension Polymerization ◽  
Polymer Chains ◽  
Synthesis Conditions ◽  
Polymeric Sorbents ◽  
Sorption Ability ◽  
Donor Acceptor ◽  
Precious Metal Ions ◽  
Selection Of

Abstract The first step in obtaining of a specific polymer sorbent containing sulfur atoms was the synthesis of a functional monomer – 2,2′-thiobisethanol dimethacrylate (TEDM). Synthesis consists of the reaction of 2,2′-thiobisethanol with methacryloyl chloride in the presence of triethylamine in methylene chloride. The new poly(dimethacrylate)s materials containing sulfur atoms were synthesized in radical suspension polymerization. Homopolymerization of 2,2′-thiobisethanol dimethacrylate and its copolymerization with ethylene glycol dimethacrylate or pentaerythritol tetraacrylate were carried out. The selection of synthesis conditions determines the parameters of the polymer structure and its properties. The presence of sulfur atoms in polymer chains resulted in specific donor-acceptor interactions, which can intensify sorption ability towards metal ions belonging to the group of soft acids. Therefore, the sorption properties of the obtained materials have been determined based on the recovery of precious metal ions, such as gold(III) and silver(I).

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