scholarly journals EFFECT OF THE MOLECULAR MASS OF POLYVINYLBUTIRAL ON THE PROPERTIES OF POLYMERS BASED ON PHOSPHORUS-CONTAINING DIMETHACRYLATE

2020 ◽  
pp. 60-65
Author(s):  
P. S. Goncharova ◽  
G. V. Korobejnikov ◽  
E. V. Pavlenko ◽  
S. V. Borisov ◽  
M. A. Vaniev ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Elastic Modulus ◽  
Molecular Mass ◽  
Dynamic Viscosity ◽  
Oxygen Index ◽  
Constant Level ◽  
Rheological Characteristics ◽  
Phosphorus Containing

The effect of the molecular weight of polyvinylbutyral dissolved in phosphorus-containing dimethacrylate on the rheological characteristics of solutions and the properties of polymers based on them has been studied. It was found that the dynamic viscosity of solutions containing 3% PVB with a molecular weight of 43,000, 57,000, and 95,000 g/mol compared with the viscosity of the phosphorus-containing dimethacrylate itself significantly increases. Depending on the molecular mass of polyvinylbutyral, materials obtained under the conditions of photochemically initiated polymerization are characterized by an increase of the elastic modulus during static bending up to 53% at a constant level of oxygen index values.

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.

Investigating the Rheological Properties and Heat Stability of Polyarylsulphone Sulphides of Domestic Grades

2017 ◽  
Vol 44 (1) ◽  
pp. 23-26
Author(s):  
A.B. Baranov ◽  
I.D. Simonov-Emel'yanov ◽  
T.I. Andreeva ◽  
T.N. Prudskova ◽  
V.I. Sazikov
Keyword(s):  
Molecular Weight ◽  
Heat Stability ◽  
Chain Structure ◽  
Low Flow ◽  
Processing Temperature ◽  
Rheological Characteristics ◽  
Melt Viscosity ◽  
Full Curve ◽  
Temperature Range ◽  
Service Characteristics

The rheological characteristics of melts of polyarylsulphone sulphides of domestic grades were investigated in the temperature range 240–360°C. Full curves of heat stability were obtained, and formulae were proposed for their description. Polyarylsulphone sulphides (PSPSs) are heat-resistant polymers of structural designation of the polysulphone (PSP) class, the domestic production technology of which was developed at OAO “Institut plastmass”, which makes it possible to carry out the production of a wide grade range of PSP of different polymer chain structure and molecular weight. The main problem in the processing of PSPSs is their high melt viscosity and fairly low flow. Increase in the processing temperature lowers their melt viscosity, but there is then the danger of thermooxidative degradation of the polymer and consequently of deterioration in the service characteristics and appearance of articles. The aim of this work was to investigate the rheological characteristics and to obtain the full curve of heat stability for domestic grades of PSPSs and PSP of different molecular weight in a wide processing temperature range.

Influence of exopolysaccharides on viscosity of sugar juices with low sucrose contents

2021 ◽  
pp. 523-528
Author(s):  
Radosław Gruska ◽  
Aneta Antczak-Chrobot ◽  
Agnieszka Sobala ◽  
Maciej Wojtczak
Keyword(s):  
Molecular Mass ◽  
Dynamic Viscosity ◽  
High Molecular Mass ◽  
Sucrose Content ◽  
Beet Sugar ◽  
The Impact ◽  
Dry Substance

The presence of dextran originating from frost-damaged or degraded beet is highly detrimental during beet sugar manufacture, because they cause difficulties in filtering the carbonatation juice. In this paper the impact of exopolysaccharides on the viscosity of low sucrose content juices including: raw juice, juice after the 1st filtration and thin juice were analyzed. Studies have shown that high molecular mass exopolysaccharides have a stronger effect on the juice viscosity than low molecular mass exopolysaccharides. However, the dynamic viscosity of technical sugar solutions (raw juice or thin juice) with exopolysaccharides at a content of up to 0.5 g/kg, is lower than the viscosity of pure sugar solutions having the same refractometric dry substance content (RDS).

The Influence of Molecular Weight on the Orientation and Properties of Polymethyl Methacrylate Sheets

2018 ◽  
Vol 45 (2) ◽  
pp. 47-51
Author(s):  
I.D. Simonov-Emel'yanov ◽  
K.V. Shirshin ◽  
P.V. Motsinov ◽  
S.V. Vlasov
Keyword(s):  
Molecular Weight ◽  
Elastic Modulus ◽  
Polymethyl Methacrylate ◽  
Considerable Increase ◽  
Deformation Characteristics ◽  
Physicomechanical Characteristics

The influence of molecular weight on the process of orientation stretching and the combination of physicomechanical characteristics of specimens of polymethyl methacrylate (PMMA) is examined. Orientation stretching and increase in the molecular weight of PMMA from 0.52 to 4.6 × 106 g/mol lead to a considerable increase in strength and elastic modulus (σt by a factor of 2.6, E by a factor of 2.5). It is established that the deformation characteristics of oriented PMMA specimens increase by a factor of 10 when the molecular weight is increased from 0.52 to 4.6 × 106 g/mol, which opens up new possibilities in the processing of sheets and films of PMMA.

scholarly journals The analysis of rheological damage of anchorage body based on visco-elasto-plastic model

2021 ◽  
Vol 303 ◽  
pp. 01060
Author(s):  
Qing-duo Wang ◽  
Feng-hai Yu ◽  
Aleksei Renev ◽  
Sergei Tsibaev ◽  
Xue-rui Yang
Keyword(s):  
Elastic Modulus ◽  
Constitutive Equation ◽  
Creep Curve ◽  
Damage Model ◽  
Rheological Characteristics ◽  
Plastic Model ◽  
Experimental Creep ◽  
Calculation Results

In order to study the rheological damage of anchorage body, rheological damage model of anchorage body is established in this paper, and it is based on visco-elasto plastic model that is often used to simulate rock rheological characteristics. The expressions of creep constitutive equation and elastic modulus of anchorage body are obtained through the analysis of rheological damage model of anchorage body, and by the fitting calculation results, finding that the theoretical creep curve is matched with the experimental creep curve under certain conditions. The research conclusions have critical significance to the bolting support and design.

Synthesis and Characterization of Phosphorus-Containing Flame Retardant Polyamide 66

2020 ◽  
Vol 977 ◽  
pp. 102-107
Author(s):  
Yu Lei Zheng ◽  
Shuang Chen ◽  
Jia Hui Wang ◽  
Ru Xiao
Keyword(s):  
Flame Retardant ◽  
Oxygen Index ◽  
Mechanical And Thermal Properties ◽  
Index Test ◽  
Polyamide 66 ◽  
Scanning Calorimetry ◽  
One Pot ◽  
Limiting Oxygen Index ◽  
Step Process ◽  
Phosphorus Containing

Polyamide 66 (PA66) benefits from excellent mechanical properties and good chemical resistance, which enabled wide application of this material in various industrial fields; however, it suffers from high flammability. Generally, preparation of a flame retardant PA from a reactive flame retardant involves a two-step process. In this study, the flame retardant PA66s (FRPA66s) are synthesized via a one-pot melt copolycondensation route by using a reactive phosphorus-containing flame retardant (FR-B). Then, molecular weight, some mechanical and thermal properties along with flame retardant properties of FRPA66s were investigated by gel permeation chromatography (GPC), instron material testing, differential scanning calorimetry (DSC), thermogravimetry (TG) analysis, vertical burning test (UL 94), and limiting oxygen index test (LOI) techniques. The experimental results confirmed that FRPA66s synthesized by the one-pot method have very similar properties compared to those obtained via the two-step process. Moreover, the prepared materials showed good non-flammability behavior with limiting oxygen index value of over 30% and a vertical burning test result of V-0 rating.

PEG Cross-Linked Alginate Hydrogels with Controlled Mechanical Properties

1998 ◽  
Vol 530 ◽  
Author(s):  
Petra Eiselt ◽  
Jon A. Rowley ◽  
David J. Mooney
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Molecular Weight ◽  
Elastic Modulus ◽  
Cell Transplantation ◽  
Cross Linking ◽  
Cross Link ◽  
Link Density ◽  
A Cell ◽  
Cross Link Density

AbstractReconstruction of tissues and organs utilizing cell transplantation offers an attractive approach for the treatment of patients suffering from organ failure or loss. Highly porous synthetic materials are often used to mimic the function of the extracellular matrix (ECM) in tissue engineering, and serve as a cell delivery vehicle for the formation of tissues in vivo. Alginate, a linear copolysaccharide composed of D-mannuronic acid (M) and L-guluronic acid (G) units is widely used as a cell transplantation matrix. Alginate is considered to be biocompatible, and hydrogels are formed in the presence of divalent cations such as Ca2+, Ba2+ and Sr2+. However, ionically cross-linked alginate gels continuously lose their mechanical properties over time with uncontrollable degradation behavior. We have modified alginate via covalent coupling of cross-linking molecules to expand and stabilize the mechanical property ranges of these gels. Several diamino PEG molecules of varying molecular weight (200, 400, 1000, 3400) were synthesized utilizing carbodiimide chemistry. Sodium alginate was covalently cross-linked with these cross-linking molecules, and mechanical properties of the resulting hydrogels were determined. The elastic modulus of the cross-linked alginates depended on the molecular weight of the cross-linking molecules, and ranged from 10-110 kPa. The theoretical cross-link density in the hydrogels was also varied from 3 to 47% (relative to the carboxylic groups in the alginate) and the mechanical properties were measured. The elastic modulus increased gradually and reached a maximum at a cross-link density of 15%. In summary, covalently coupled hydrogels can be synthesized which exhibit a wide range of mechanical properties, and these materials may be useful in a number of tissue engineering applications.

scholarly journals Polyamide 1010/Polythioamide Blend Reinforced with Graphene Nanoplatelet for Automotive Part Application

2017 ◽  
Vol 17 (3) ◽  
pp. 24-36 ◽  
Author(s):  
A. Kausar
Keyword(s):  
Molecular Weight ◽  
Tensile Strength ◽  
Shear Stress ◽  
Oxygen Index ◽  
Flexural Modulus ◽  
Graphene Nanoplatelet ◽  
Limiting Oxygen Index ◽  
Index Measurement ◽  
Automotive Part ◽  
Polyamide 1010

Abstract Novel polythioamide (PTA) was prepared and blended with polyamide 1010 (PA1010). Based on morphology, molecular weight, polydispersity index, thermal, and shear stress behavior, PA1010/PTA (90:10) blend was opted as matrix for graphene nanoplatelet (GNP) reinforcement. Inclusion of functional GNP resulted in crumpled gyroid morphology. T0 (502°C) of PA1010/PTA/GNP was increased by 145°C than unfilled blend (357°C). Limiting oxygen index measurement indicated better non-flammability of PA1010/PTA/GNP1-3 nanocomposites (53-55%) relative to PA1010/PTA1-3 (41-48%). PA1010/PTA/GNP1-3 also attained V-0 rating in UL94. Furthermore, PA1010/PTA/GNP3 nanocomposite revealed optimum tensile strength (40 MPa), impact strength (1.9 MPa), and flexural modulus (1373 MPa) to manufacture automotive part.

High Molecular Weight Polyethylene Nanospheres: Synthesis Physical and Mechanical Properties

2008 ◽  
Vol 8 (6) ◽  
pp. 3123-3135 ◽  
Author(s):  
Pradip Paik ◽  
Kamal K. Kar
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Particle Size ◽  
Electron Microscope ◽  
Elastic Modulus ◽  
High Molecular Weight ◽  
Melting Temperature ◽  
Ion Beam ◽  
Atomic Scale ◽  
Scanning Calorimetry

The high molecular weight (MW) polyethylene (PE) particles of particle size varied from macro to micron to nanometer were synthesized by Grignard reagent. The microscopy analysis (scanning electron microscope, SEM; transmission electron microscope, TEM; and atomic force microscope, AFM) shows the spherical shape of PE particles. The effects of particle size, varies from macro to nanometer scale on crystal structure, crystallinity (χc), glass transition temperature (Tg), melting temperature (Tm), surface roughness and mechanical properties were studied. Differential scanning calorimetry (DSC) experiments show that the nanoparticles of PE are highly crystalline (χc ≈ 72%). The crystal length of PE nanoparticles is found to be approximately 14 Å. Although the Gibbs-Thomson equation is explained the depression of melting temperature (ΔTm) by 5 °C, the impervious results of Tg are still not fully understood. The low roughness value (2 Å) proves the presence of "atomic-scale-chain" folding at the surface of PE nanoparticles. A novel protocol is developed, and the elastic modulus of individual nanospherical PE particles is computed from 'force-distance' mapping curves of AFM. Hemispherical tungsten (W) tip was fabricated from focused ion beam and used as an indenter to measure the mechanical properties. It is found that the nano sized PE particles have higher elastic modulus (E = 1.2–1.4 GPa) compared to the bulk or macro sized PE (E = 0.6–0.7 GPa). The results corroborate the robustness of our experiments, since, the analogous results for macro sized particles match well with the literature.

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