Synthesis of Polyvinyl Formal Sponge for Wound Care Dressing Application

2010 ◽  
Vol 152-153 ◽  
pp. 1650-1659
Author(s):  
Qing Hao Yang ◽  
Guang Xu Cheng ◽  
Zhi Cheng Zhang
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Porous Structure ◽  
Pore Structure ◽  
Water Absorption ◽  
Wound Dressing ◽  
Wound Care ◽  
Acid Catalyst ◽  
The Other ◽  
Polyvinyl Formal

In an effort to seek poly(vinyl formal) (PVFM) foams based wound dressing pad material, a series of foamed PVFM materials have been synthesized under varied conditions. The influence of conditions on the properties of PVFM foam, such as mechanical properties, water absorption, pore structure and bulk density, is well discussed individually. It has been shown that both the reactant and acid catalyst affect the degree and speed of acetalization, therefore the mechanical properties, pores continuity and water absorption of the resultant sample. The addition of Na2CO3, surfactant and CMCNa are mainly influencing the porous structure as well as the mechanical properties and water absorption. One best sample with balanced properties is obtained. It possesses higher mechanical strength and water absorption while the other properties are similar, comparing with a commercial surgical PVFM sponge (YJ-1) currently used.

Studies of Mechanical Properties and Absorption of Lightweight Concrete with Brazilian Expanded Clay

2013 ◽  
Vol 742 ◽  
pp. 231-236 ◽  
Author(s):  
Andressa Fernanda Angelin ◽  
Rosa Cristina Cecche Lintz ◽  
Luísa Andréia Gachet-Barbosa
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Specific Gravity ◽  
Pore Structure ◽  
Water Absorption ◽  
Rotary Kiln ◽  
Manufacturing Process ◽  
Lightweight Concrete ◽  
The Other ◽  
Viscous Mass

Brazilian Expanded Clay. The production process in a rotary kiln (or nodule) used in Brazil, characterized by the fact that certain materials expand when subjected to high temperatures (between 1000 °C and 1350 °C), such as some clays. In this temperature range, some of the material melts generating a viscous mass, while the other part chemically decomposes releasing gases which are incorporated by this mass, expanding by up to seven times its initial volume, the pore structure being maintained after its cooling. This manufacturing process promotes the formation of a glazed layer on the outside with low particle porosity, which significantly reduces the water absorption, has varying particle size and regular rounded shape, and its specific gravity comprised within the range from 0.64 to 1.51 kg/dm3 [4, .

scholarly journals Effects of water absorption on the mechanical properties of hybrid natural fibre/phenol formaldehyde composites

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sekar Sanjeevi ◽  
Vigneshwaran Shanmugam ◽  
Suresh Kumar ◽  
Velmurugan Ganesan ◽  
Gabriel Sas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Water Absorption ◽  
Hybrid Composites ◽  
Phenol Formaldehyde ◽  
Natural Fibre ◽  
The Other ◽  
Fibre Reinforcement ◽  
Dry Conditions

AbstractThis investigation is carried out to understand the effects of water absorption on the mechanical properties of hybrid phenol formaldehyde (PF) composite fabricated with Areca Fine Fibres (AFFs) and Calotropis Gigantea Fibre (CGF). Hybrid CGF/AFF/PF composites were manufactured using the hand layup technique at varying weight percentages of fibre reinforcement (25, 35 and 45%). Hybrid composite having 35 wt.% showed better mechanical properties (tensile strength ca. 59 MPa, flexural strength ca. 73 MPa and impact strength 1.43 kJ/m2) under wet and dry conditions as compared to the other hybrid composites. In general, the inclusion of the fibres enhanced the mechanical properties of neat PF. Increase in the fibre content increased the water absorption, however, after 120 h of immersion, all the composites attained an equilibrium state.

Preparation Techniques and Property Evaluations of Highly Air Permeable Needle-Punched Geotextiles

2015 ◽  
Vol 749 ◽  
pp. 278-281
Author(s):  
Jia Horng Lin ◽  
Jing Chzi Hsieh ◽  
Jin Mao Chen ◽  
Wen Hao Hsing ◽  
Hsueh Jen Tan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Service Life ◽  
Mechanical Strength ◽  
Pore Structure ◽  
Test Results ◽  
Needle Punching ◽  
Pet Fibers ◽  
Environmental Requirements ◽  
Preparation Techniques

Geotextiles are made of polymers, and their conjunction with different processes and materials can provide geotextiles with desirable characteristics and functions, such as filtration, separation, and drainage, and thereby meets the environmental requirements. Chemical resistant and mechanical strong polymers, including polyester (PET) and polypropylene (PP), are thus used to prolong the service life of the products made by such materials. This study proposes highly air permeable geotextiles that are made with different thicknesses and various needle punching speeds, and the influences of these two variables over the pore structure and mechanical properties are then examined. PET fibers, PP fibers, and recycled Kevlar fibers are blended, followed by being needle punched with differing spaces and speeds to form geotextiles with various thicknesses and porosities. The textiles are then evaluated for their mechanical strength and porosity. The test results show that a thickness of 4.5 cm and 1.5 cm demonstrate an influence on the tensile strength of the geotextiles, which is ascribed to the webs that are incompletely needle punched. However, the excessive needle punching speed corresponding to a thickness of 0.2 cm results in a decrease in tensile strength, but there is also an increase in the porosity of the geotextiles.

scholarly journals Sintesis Hidrogel Pektin – Gelatin dengan Penambahan Ekstrak Kulit Buah Naga Sebagai Kandidat Pembalut Luka Bakar

2020 ◽  
Vol 4 (1) ◽  
pp. 53
Author(s):  
Fadhil Muhammad Tarmidzi ◽  
Inggit Kresna Maharsih ◽  
Tina Raihatul Jannah ◽  
Cici Sari Wahyuni
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Citric Acid ◽  
Wound Dressing ◽  
Wound Care ◽  
Crosslinking Agent ◽  
Wound Dressings ◽  
Esterification Reaction ◽  
Natural Polymers ◽  
Fruit Peel

Teknik pembalutan luka saat ini menerapkan metode perawatan luka modern dengan cara mempertahankan isolasi lingkungan luka dalam keadaan tertutup dan lembab. Ada beberapa jenis pembalut luka yang telah dikembangkan, salah satunya hidrogel. Hidrogel merupakan pembalut luka berbentuk lembaran yang memiliki kemampuan menyerap cairan luka dan memiliki stabilitas yang baik pada pH asam sehingga dapat digunakan untuk pengobatan luka bakar. Dalam penelitian ini, hidrogel dibuat menggunakan polimer alami seperti pektin dan gelatin. Kedua bahan tersebut dikombinasikan menggunakan metode ikatan silang dengan penambahan asam sitrat sebagai agen pengikat silang. Penambahan asam sitrat memberikan pengaruh terhadap karakteristik material hidrogel yang dihasilkan, sehingga diperlukan jumlah yang tepat agar didapatkan hidrogel dengan properti material yang baik. Hidrogel juga ditambahkan zat aktif berupa flavonoid pada ekstrak kulit buah naga agar dapat digunakan sebagai pembalut luka untuk menyembuhkan luka bakar. Dari hasil penelitian, hidrogel dengan konsentrasi asam sitrat 4% (Hidrogel CA 4%) menghasilkan nilai swelling, tensile strength, dan elongation tertinggi sebesar 890%, 0,05 Mpa, dan 200%. Hasil properti mekanik dari Hidrogel CA 4% ini dibuktikan dengan uji FTIR yang telah dilakukan, yaitu munculnya gugus karbonil C=O sebagai hasil reaksi esterifikasi yang terjadi antara polimer dengan asam sitrat di daerah serapan 1733,9 cm-1.Wound dressing technique currently applies modern wound care methods by maintaining the environmental isolation of the wound in a closed and moist state. There are several types of wound dressing that have been developed, one of them is hydrogel. Hydrogel is sheet-shaped wound dressings which have the ability to absorb exudate and have good stability acidic pH that can be used for the treatment of burns. In this study, hydrogel were made using natural polymers such as pectin and gelatin. The two polymers were combined using crosslinking method with the addition of citric acid as a crosslinking agent. The addition of citric acid has affect on the characteristics of the hydrogel material produced, therefore the right amount is needed to obtain a hydrogel with good mechanical properties. Hydrogel also added by an active substance in the form of flavonoids from dragon fruit peel extract that can be used as a wound dressing to cure burns. This study resulting hydrogel with a concentration of 4% citric acid (Hydrogel CA 4%) produced highest value of swelling, tensile strength, and elongation are 890%, 0.05 Mpa, and 200%, repectively. The mechanical properties of Hydrogel CA 4% was proved by FTIR test that had been carried out, namely the presence of C=O carbonyl group as a result of the esterification reaction that occurred between the polymers and citric acid in the absorption area of 1733.9 cm-1.

Effect of Alumina (Al2O3) to the Properties of Whiteware Porcelain

2020 ◽  
Vol 1010 ◽  
pp. 194-199
Author(s):  
Hamdan Yahya ◽  
Aspaniza Ahmad ◽  
Ismail Ibrahim
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Water Absorption ◽  
Bulk Density ◽  
Physical And Mechanical Properties ◽  
Porcelain Body ◽  
The Other ◽  
Alumina Content ◽  
Crystalline Phases ◽  
Mullite Phase

The effect of Al2O3 to the properties of whiteware porcelain such as water absorption, bulk density, flexural strength and crystalline phases were studied systematically. The result shows that the addition of alumina at maximum 5 wt.% in porcelain bodies increased the flexural strength of the fired bodies which can reach 55.5 MPa, 30% higher than 0.0% alumina content. However, slight decrease in the other physical and mechanical properties was observed with Al2O3 addition higher than 5 wt.%, which is believed to be due to increased corundum phase compared to mullite phase in porcelain body.

Incorporation of Petroleum Coke into Red Ceramic

2010 ◽  
Vol 660-661 ◽  
pp. 681-685
Author(s):  
Carlos Maurício Fontes Vieira ◽  
Lussandra Arêdes Freitas ◽  
Rubén Jesus Sánchez Rodríguez ◽  
Sérgio Neves Monteiro
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Water Absorption ◽  
Optical Microscopy ◽  
Petroleum Coke ◽  
Rupture Strength ◽  
Physical And Mechanical Properties ◽  
Refining Plant

This work has as its objective to evaluate the effect in the physical and mechanical properties of a red ceramic by the incorporation of petroleum coke from a refining plant. The characterization of the coke was done by optical microscopy and DTA/TG. Compositions were prepared with 0, 1, 2 and 4 wt.% of petroleum coke incorporated into a kaolinitic clayey body. Rectangular specimens were formed by extrusion before firing at 950°C. The determined physical and mechanical properties were: flexural rupture strength and water absorption. The microstructure of the fired ceramics was evaluated by SEM. The results showed that the incorporation of up to 4 wt.% of petroleum coke is not deleterious to the water absorption and mechanical strength of the clayey ceramic fired at 950oC.

scholarly journals The effect of silanes as integral hydrophobic admixture on the physical properties of cement based materials

2021 ◽  
Vol 2069 (1) ◽  
pp. 012045
Author(s):  
K Grabowska ◽  
A Wieczorek ◽  
D Bednarska ◽  
M Koniorczyk
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Physical Properties ◽  
Water Absorption ◽  
Cement Mortar ◽  
Organosilicon Compounds ◽  
Capillary Water ◽  
Main Ingredient ◽  
Capillary Water Absorption ◽  
Cement Based Materials

Abstract The paper explores the possibility of using organosilicon compounds (e.g., poly(dimethylsiloxane) and triethoxyoctylsilane) in commercial admixtures as internal hydrophobization agents for porous cement-based materials. The study involved the cement mortar with five different hydrophobic admixtures. Four of them is based on triethoxyoctylsilane, but with various concentration of the main ingredient, and one of them on poly(dimethylsiloxane). Mechanical properties, capillary water absorption, as well as microstructure were investigated. The organosilicon admixtures efficiently decrease the capillary water absorption even by 81% decreasing mechanical strength of cement mortar at the same time even by 55%. Only one admixture, based on poly(dimethylsiloxane) caused significant changes in microstructure of cement mortar.

scholarly journals Low Water Absorption, High-Strength Polyamide 6 Composites Blended with Sustainable Bamboo-Based Biochar

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1367
Author(s):  
Shiliu Zhu ◽  
Yong Guo ◽  
Yuxia Chen ◽  
Shengquan Liu
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Water Absorption ◽  
High Strength ◽  
Polyamide 6 ◽  
Negative Effects ◽  
Plant Fibers ◽  
Maximum Decrease ◽  
Bamboo Fibers ◽  
The Impact

To promote the application of polyamide 6 (PA6) in wood–plastic composites, the negative effects associated with the thermal degradation of plant fibers must be overcome. In this study, waste bamboo fibers were subjected to pyrolysis and ball milling to afford nano bamboo-based biochar (BC), which was subsequently used as reinforcement to prepare PA6/BC nano composites by injection molding. In addition, the processing fluidity, water absorption, mechanical properties, and interface compatibility of PA6/BC composites were discussed. Results revealed that a BC content of less than 30 wt% is beneficial to improve the processing fluidity of the composites. With the increase in the BC content, the density of the PA6/BC composites gradually increased, while the water absorption of the PA6/BC composites gradually decreased, and the maximum decrease was 46%. Compared to that of pure PA6, the mechanical strength of PA6/BC composites was improved by the addition of BC, and the maximum tensile/flexural strength and modulus of PA6/BC composites increased by 41%/72% and 195%/244%, respectively. However, the impact strength decreased by 27%. After immersion treatment, the dimensional stability and mechanical strength of the composites decreased, while toughness improved. At a BC content of less than 40 wt%, BC particles exhibited good dispersibility and wettability in the PA6 matrix, and the rough surface and rich pore structure of BC rendered strong mechanical interlocking effects and good interface compatibility, thereby enhancing the mechanical properties of the composites.

A Study of Ramie Fiber Reinforced Polypropylene Composites

2011 ◽  
Vol 194-196 ◽  
pp. 1839-1844 ◽  
Author(s):  
Yi Ming Sun ◽  
Dan Peng ◽  
Man Li
Keyword(s):  
Mechanical Properties ◽  
Maleic Anhydride ◽  
Mechanical Strength ◽  
Water Absorption ◽  
Ramie Fiber ◽  
Hydroxyl Groups ◽  
Polypropylene Composites ◽  
Surfaces And Interfaces ◽  
Ramie Fibers ◽  
Polypropylene Matrix

Ramie fibers were incorporated into polypropylene as the reinforcement fillers. The transesterification between the hydroxyl groups of ramie fiber and the ester of maleic anhydride was employed to improve the compatibility of ramie fibers and the polypropylene matrix. The morphology of the composite surfaces and interfaces were studied using IR and SEM. The mechanical properties and water absorption of the composites were investigated. The results demonstrated that the esterification occurred on the surface of ramie fiber, due to which the compatibility between fiber and matrix treated was greatly improved. Because of the improved compatibility, the mechanical strength of the composites increased; while water absorption decreased.

The effect of alkaline–silane treatment of rubberwood flour for water absorption and mechanical properties of plastic composites

2018 ◽  
Vol 33 (5) ◽  
pp. 599-613 ◽  
Author(s):  
Sriwan Khamtree ◽  
Thanate Ratanawilai ◽  
Sukritthira Ratanawilai
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Water Absorption ◽  
Morphological Characterization ◽  
Silane Treatment ◽  
Plastic Composites ◽  
Treatment Conditions ◽  
Twin Screw ◽  
Effect Of Treatment

Rubberwood flour (RWF) was treated by alkaline, silane, and alkaline–silane, and consequently, reinforced recycled polypropylene (rPP) composites. The wood–plastic composites (WPCs) were prepared with 40 wt% RWF content using a twin-screw extruder, followed by compression molding. Silane treatment was applied at various concentrations and treatment times to evaluate the effect of treatment conditions on water absorption, mechanical properties, thermal properties, and morphological characterization of WPCs. The results indicated that alkaline–silane treatment of RWF exhibits higher properties in comparison to silane or alkaline only. In addition, silane concentrations significantly affected water absorption, mechanical strength, and hardness, while treatment times remained relatively unaffected by these properties. The best water resistance, mechanical strength, and hardness of WPCs were achieved by alkaline–silane treatment with 5% silane concentration for 2 h, which improved the interfacial adhesion of RWF and rPP as well as increased the crystallinity in the WPCs.

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