scholarly journals Influence of Polymer-Silicate Nucleator on the Structure and Properties of Polyamide 6

2020 ◽  
Vol 14 (4) ◽  
pp. 496-503
Author(s):  
Volodymyr Levytskyi ◽  
◽  
Andrii Masyuk ◽  
Diana Katruk ◽  
Rafał Kuzioła ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Crystallite Size ◽  
Softening Point ◽  
Surface Hardness ◽  
Chemical Properties ◽  
Polyamide 6 ◽  
Structure And Properties ◽  
Crystallinity Degree ◽  
Physico Chemical ◽  
Silicate Materials

Physico-chemical properties of developed nickel-containing modified silicate materials as the nucleators for composites based on polyamide 6 are presented. As it was established, additive of the nucleator modified by polyvinylpyrrolidone promotes the increase of crystallinity degree of polyamide 6 and the decrease of crystallite size. It was found that changes in the structure of the material cause the increase of its tensile strength, surface hardness and Vicat softening point.

Chemical Modification Treatments on Extra-Long Egyptian Cotton Fiber

2021 ◽  
Vol 8 (1) ◽  
Keyword(s):  
Tensile Strength ◽  
Sodium Hydroxide ◽  
Cotton Fiber ◽  
Fiber Length ◽  
Chemical Properties ◽  
Color Strength ◽  
Crystallinity Degree ◽  
Moisture Regain ◽  
Egyptian Cotton ◽  
Color Components

The efficiency of physical and chemical properties on Extra-long stable Egyptian cotton fiber Giza 96 at different treatment processes with two concentrations of morpholine comparing with conventional treatment with sodium hydroxide (NaOH) was investigated. The sample was pretreated with ferrous sulfate before dyeing with direct dye or natural dye. Physical properties as tensile strength (g/tex), elongation %, fiber length (UHM, and U.I), micronaire reading, reflectance (Rd %), and yellowness (+b) as well as chemical properties as crystallinity degree, moisture regain, accessibility, color strength (K/S), color components and color difference (?E) was also investigated. The results show that the chemical modified cotton fiber with sodium hydroxide (NaOH) were increased amorphous cellulose %, moisture regain %, accessibility %, fiber uniformity index (U.I) %, elongation %, and micronaire reading compared with morpholine treatments. On the other hand, tensile strength, and fiber length (U.H.M), decreased with a little degree values in morpholine treatments comparing with sodium hydroxide. Improvement in color strength (K/S), and color components was observed using morpholine instead of NaOH. These results were important for finishing textile production and textile industry.

Influence of Copolymer Architecture on Generation of Defects in Reactive Multilayer Coextrusion

2015 ◽  
Vol 651-653 ◽  
pp. 836-841 ◽  
Author(s):  
Arnaud Bondon ◽  
Khalid Lamnawar ◽  
Abderrahim Maazouz
Keyword(s):  
Chemical Properties ◽  
Polyamide 6 ◽  
Interface Roughness ◽  
Interfacial Instabilities ◽  
Influence Of Process Parameters ◽  
Ethylene Vinyl Alcohol ◽  
Barrier Layers ◽  
Interfacial Morphology ◽  
Physico Chemical

Several polymers can be combined in one multilayer structure by reactive coextrusion. Tie-layers are often used to compatibilize adjacent layers and may reduce or suppress interfacial instabilities and defects in multilayer coextrusion flow. However, a new additional defect defined as “grainy” defect can be observed. In our best of knowledge, no study in literature has been dedicated to understand its origin. The phenomena are quite complex due to the coupling of the effects of flow and the physico-chemical mechanisms at the interface. The aim of this work is to understand the relationship between the instabilities and defects encountered in multilayer coextruded films and the role of the copolymer formed in-situ between tie and barrier layers. Polyamide 6 (PA6) and ethylene-vinyl alcohol copolymer (EVOH) were used as barrier layers sandwiched in polypropylene (PP) with or without tie-layer based on polypropylene grafted maleic anhydride (PP-g-MA). Influence of process parameters and nature of the polymer pair on the generation of “grainy” defect has been assessed and related to the rheological and the physico-chemical properties of layers. These experiments showed that this defect appeared mainly in the compatibilized EVOH system and could be distinguished from the usual coextrusion instabilities. Interfacial properties between tie and barrier layers have been investigated. Shear stress relaxation experiments have been carried out on reactive tie/barrier bilayers. Due to the interphase generated in-situ, the relaxation behavior was altered by extending the relaxation time. Investigation of interfacial morphology highlighted that the copolymer architecture significantly affected the interface/interphase development and interface roughness. Hence, relationships between relaxation process, interfacial morphology and copolymer structure were correlated with the generation of grainy defects in coextrusion.

scholarly journals Effect of Modifying Shellac with Citric Acid on Shellac-Bagasse Biocomposite

2019 ◽  
Vol 32 (1) ◽  
pp. 13-16
Author(s):  
Nanik Dwi Nurhayati ◽  
Karna Wijaya ◽  
Triyono ◽  
Eddy Heraldy
Keyword(s):  
Tensile Strength ◽  
Citric Acid ◽  
Intrinsic Viscosity ◽  
Testing Machine ◽  
Chemical Properties ◽  
Low Density ◽  
Universal Testing Machine ◽  
Universal Testing ◽  
Physico Chemical ◽  
Mechanical Tensile

This study was aimed at modifying local Shellac with citric acid in varied concentrations of 2, 4, 6, 8 and 10 % (w/w) to prepare Shellac-Bagasse (Sh-Bg) biocomposite and determining its physico-chemical properties. The biocomposite was made from the natural Shellac matrices and Bagasse fibers. Physico-chemical properties of non-modified Shellac and Shellac modified with citric acid including functional groups, intrinsic viscosity, density, and mechanical tensile strength were characterized using Fourier transform infrared spectrometer (FTIR), Oswald viscometer and Universal Testing Machine (UTM). The analysis results showed an optimum modification of shellac-citric acid at a concentration of 4% (w/w). FTIR analysis of the modified Shellac showed a broad absorption at 3448 cm–1 which indicated the presence of hydroxyl groups (-OH). The presence of C=O ester groups was indicated by the absorption appearing at 1712 cm–1. The absorption at 1251-1250 cm–1 indicated the presence of C-O groups, while the presence of -CH2 methylene groups was indicated by the absorption at 1465 cm–1. The modified Shellac with its optimal intrinsic viscosity of 169.97 mL/g indicated that there was a reaction between citric acid and Shellac to form an ester, so that the polymer chains formed were longer with a low density of 0,6662-0,8168 mg/L when compared to Shellac without modification. The low density indicated that the citric acid-modified Shellac could be processed to be biocomposite. The biocomposite was made with various compositions of Shellac and Bagasse with hot press at 80 °C and under a pressure of 6 Kgf/cm2. The optimum ratio of Shellac to Bagasse in Shellac-Bagasse (Sh-Bg) biocomposite was of 60:40 %. While, the analysis using Universal testing machine resulted a mechanical tensile strength of 0.6 MPa and an elongation at break of 0.45 %.

scholarly journals Physico-Chemical Properties of Nickel Promoted Sulfated Zirconia Powder Prepared using Different Procedures

2020 ◽  
Vol 32 (3) ◽  
pp. 555-560
Author(s):  
Amalia Kurnia Amin ◽  
Karna Wijaya ◽  
Wega Trisunaryanti
Keyword(s):  
Crystallite Size ◽  
Sulfated Zirconia ◽  
Pore Volume ◽  
Chemical Properties ◽  
Acid Sites ◽  
Impregnation Method ◽  
Zirconia Powder ◽  
Ammonia Adsorption ◽  
Physico Chemical ◽  
Zirconia Support

In this work, nickel promoted sulfated zirconia (Ni/SZ) as catalyst was prepared by either by reflux (Ni/SZ-R) or hydrothermal Ni impregnation (Ni/SZ-H) routes. The aim of this study was to evaluate the influences of two preparative methods on the physico-chemical properties of prepared catalysts. Both the catalysts were characterized by XRD, FTIR, ammonia adsorption, SEM-EDX, TEM-SAED, AAS and BET. It was found that the presence of sulfate and nickel could enhance the Brønsted and Lewis active acid sites. In relation to the effect of Ni impregnation method, acidity, amount of sulfate and Ni found in Ni/SZ-R were higher than those in Ni/SZ-H. Unfortunately, higher impregnated sulfate and nickel on zirconia support led to a decrease in surface area and pore volume and an increase in crystallite size of grainy aggregated mesoporous nickel promoted sulfated zirconia (Ni/SZ).

Nano Structure and Properties of Beta–D-Poly-Glucopyranose

2010 ◽  
Vol 123-125 ◽  
pp. 739-742
Author(s):  
Oleg Figovsky ◽  
Michael Ioelovich
Keyword(s):  
Phase Transformation ◽  
Structural Characteristics ◽  
Chemical Properties ◽  
Supermolecular Structure ◽  
Structure And Properties ◽  
Surface Layers ◽  
Nano Structure ◽  
Nano Scale ◽  
Physico Chemical ◽  
Multi Level

Beta–D-poly-glucopyranose is widespread class of the natural semi-crystalline polysaccharide known as cellulose. This polymer has complicated multi-level supermolecular structure. It is built from elementary nano-fibrils and their aggregates; moreover, each nano-fibril contains ordered nanocrystallites and low-ordered amorphous nano-domains. Therefore cellulose can be a pronounced and eminent representative of nano-structured matters. Such nano matter has peculiar physico-chemical properties depending on specific surface of nano-scale constituents. In this paper, physico-chemistry of the nano-structured cellulose is discussed. In particular, the ability of nano-scale crystallites to co-crystallization and aggregation, as well as their ability to phase transformation through dissolution, alkalization and chemical modification was a subject of the investigation. Structural characteristics of paracrystalline surface layers of nano-crystallites and their effect on physico-chemical properties of the polysaccharide have been discussed.

scholarly journals THE EFFECT OF HYDROGEL DRESSING COPOLYMER POLI(VINYLPIRROLIDONE) (PVP) - k- CARRAGEENAN PREPARED BY RADIATION AND HEALING TIMES ON THE RADIUS REDUCTIONS BURN INJURIED OF WISTAR WHITE RAT

2010 ◽  
Vol 8 (2) ◽  
pp. 271-278
Author(s):  
Erizal Erizal
Keyword(s):  
Tensile Strength ◽  
Clinical Study ◽  
Aqueous Solutions ◽  
Water Absorption ◽  
Water Content ◽  
Wound Dressing ◽  
Chemical Properties ◽  
Physico Chemical ◽  
Time Observation ◽  
Sterilization Dose

The pre-clinical study of poly (vinyl pirrolidone) (PVP)-k- carrageenan hydrogel has been carried out. The aim of this study is to investigate the effect of hydrogel for healing burn injuried in the rats. The hydrogels were prepared by g-irradiation of aqueous solutions of 15 wt.-% PVP and 2 wt.-% k- carrageenan at a sterilization dose of 25 kGy. The physico-chemical properties of hydrogels were investigated. The results showed that the hydrogels suitable as candidate for wound dressing with gel fraction of 90 ± 5 (%), the water absorption was 4500 ± 55 (w/w), the water content was 83 ± 2 (%), tensile strength was 1,5 ± 0,1 kg/cm2 and adhesiveness was 0. The effect of the hydrogel as wound dressing was evaluated by attaching to a burn of the back skin of rats as a function of time observation. Advantages of the hydrogel were slightly faster rate of reducing radius diameter of injured burn skin, easy removal without damage to renewed skin.   Keywords: hydrogel, irradiation, copolymer, PVP, k carrageenan, diameter

Physico-Chemical Properties of Edible Gelatin Film from Arrowtooth Flounder (Atheresthes Stomias) Skin

2011 ◽  
Vol 328-330 ◽  
pp. 1408-1412
Author(s):  
Jian Wei Li ◽  
Qian Cheng Zhao ◽  
Bing Bing Wang
Keyword(s):  
Tensile Strength ◽  
Proximate Composition ◽  
Chemical Properties ◽  
Gelatin Film ◽  
Edible Film ◽  
Elongation At Break ◽  
Physico Chemical ◽  
Arrowtooth Flounder

Fish wastes such as bones and skins, has been under-utilized. Gelatin was extracted from frozen Arrowtooth flounder (Atheresthes stomias) skin (AFS), and the edible gelatin film was successfully prepared. The results showed that the proximate composition of moisture, protein, lipid and ash of the extracted gelatin was 6.0 %, 92.8 %, 0.31 % and 0.39 %, respectively. The pH, bloom strength and viscosity of gelatin was 6.0, 234.8 g and 4.3 mPa.s, respectively. The tensile strength (TS), elongation at break (EAB), solubility and the prepared edible film were 10.3 MPa, 51.4 %, 98.3 %, and the film was transparent.

Decoration of specific sites on freeze-fractured membranes

1978 ◽  
Vol 36 (2) ◽  
pp. 140-141
Author(s):  
H. Gross ◽  
H. Moor
Keyword(s):  
Pure Water ◽  
Freeze Fracture ◽  
Chemical Properties ◽  
Surface Forces ◽  
Sulfate Pentahydrate ◽  
Copper Sulfate Pentahydrate ◽  
Physico Chemical ◽  
Water Of Hydration ◽  
Small Container ◽  
Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

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