scholarly journals Effect of Glycero-(9,10-trioxolane)-trialeate on the Physicochemical Properties of Non-Woven Polylactic Acid Fiber Materials

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2517
Author(s):  
Anatoliy Olkhov ◽  
Olga Alexeeva ◽  
Marina Konstantinova ◽  
Vyacheslav Podmasterev ◽  
Polina Tyubaeva ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Polylactic Acid ◽  
Specific Surface Area ◽  
Water Sorption ◽  
Fiber Surface ◽  
High Water ◽  
Scanning Calorimetry ◽  
Fiber Mats ◽  
Fiber Materials

Biocompatible glycero (9,10-trioxolane) trioleate (ozonide of oleic acid triglyceride, OTOA) was incorporated into polylactic acid (PLA) fibers by electrospinning and nonwoven PLA mats with 1%, 3% and 5% OTOA content. The morphological, mechanical, thermal and water sorption properties of electrospun PLA mats after the addition of OTOA were studied. A morphological analysis showed that the addition of OTOA increased the average fiber diameter and induced the formation of pores on the fiber surface, leading to an increase in the specific surface area for OTOA-modified PLA fibrous mats. PLA fiber mats with 3% OTOA content were characterized by a highly porous surface morphology, an increased specific surface area and high-water sorption. Differential scanning calorimetry (DSC) was used to analyze the thermal properties of the fibrous PLA mats. The glass transition temperatures of the fibers from the PLA–OTOA composites decreased as the OTOA content increased, which was attributed to the plasticizing effect of OTOA. DSC results showed that OTOA aided the PLA amorphization process, thus reducing the crystallinity of the obtained nonwoven PLA–OTOA materials. An analysis of the mechanical properties showed that the tensile strength of electrospun PLA mats was improved by the addition of OTOA. Additionally, fibrous PLA mats with 3% OTOA content showed increased elasticity compared to the pristine PLA material. The obtained porous PLA electrospun fibers with the optimal 3% OTOA content have the potential for various biomedical applications such as drug delivery and in tissue engineering.

scholarly journals The Effects of Silica-Based Fillers on the Properties of Epoxy Molding Compounds

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1811 ◽  
Author(s):  
Mitja Linec ◽  
Branka Mušič
Keyword(s):  
Mechanical Properties ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Fused Silica ◽  
Spiral Flow ◽  
Scanning Calorimetry ◽  
Molding Compounds ◽  
Material Development ◽  
The Impact

Global design and manufacturing of the materials with superb properties remain one of the greatest challenges on the market. The future progress is orientated towards researches into the material development for the production of composites of better mechanical properties to the existing materials. In the field of advanced composites, epoxy molding compounds (EMCs) have attained dominance among the common materials due to their excellent properties that can be altered by adding different fillers. One of the main fillers is often based on silicon dioxide (SiO2). The concept of this study was to evaluate the effects of the selected silica-based fillers on the thermal, rheological, and mechanical properties of EMCs. Various types of fillers with SiO2, including crystalline silica and fused silica, were experimentally studied to clarify the impact of filler on final product. Fillers with different shape (scanning electron microscope, SEM), along with different specific surface area (specific surface area analyzer, BET method) and different chemical structure, were tested to explore their modifications on the EMCs. The influence of the fillers on the compound materials was determined with the spiral flow length (spiral flow test, EMMI), glass transition temperature (differential scanning calorimetry, DSC), and the viscosity (Torque Rheometer) of the composites.

Microstructural and porosimetry analysis of Ag-TiO2intercalated kaolin and diatomite as nanocomposite ceramic materials

Clay Minerals ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 665-674 ◽  
Author(s):  
Emmanuel Ajenifuja ◽  
Abimbola P.I. Popoola ◽  
Kabir O. Oyedotun ◽  
Olawale Popoola
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Ceramic Materials ◽  
Mineral Particle ◽  
Scanning Calorimetry ◽  
Sintered Ceramic ◽  
Morphological Studies ◽  
Bet Specific Surface Area ◽  
Bet Analysis

ABSTRACTKaolin and diatomite are abundant and widely available geological materials that may immobilize or stabilize functional chemical species on their surfaces for various applications. Acid-treated kaolin and diatomite were intercalated with photocatalyst Ag-TiO2nanoparticles using the sol–gel technique to prepare nanocomposite ceramic materials. The nanocomposites were sintered between 900°C and 1000°C to induce thermal reactions and to enhance nanoparticle–substrate attachment. Chemical and thermal characterizations of the acid-treated materials and intercalated nanocomposites were performed with energy-dispersive X-ray (EDX) analysis and differential scanning calorimetry (DSC), respectively. The Brunauer–Emmett–Teller (BET)-specific surface area and scanning electron microscopy (SEM) were employed for physical and microstructural characterization of the nanocomposites, respectively. Morphological studies revealed a uniform distribution of Ag-TiO2nanocrystallites in pores and on mineral particle surfaces. The BET analysis showed remarkable surface and grain modification by sintering. Decreases in the BET-specific surface area were observed for the sintered ceramic nanocomposite, Ag-TiO2-kaolin (20.244 to 5.446 m2/g) and Ag-TiO2-diatomite (19.582 to 10.148 m2/g).

scholarly journals Modificação das propriedades da poliamida 12 pela incorporação de carbonato de cálcio nanoparticulado

2020 ◽  
Author(s):  
◽  
R. M. S. Teotonio
Keyword(s):  
Impact Strength ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Flexural Modulus ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Crystallinity Degree ◽  
Bet Analysis ◽  
The Matrix

Polyamide 12 (PA12) was modified by incorporating calcium carbonate nanoparticles (NPCC) to analyze the effect of the filler content on the mechanical and thermal properties of the final nanocomposites. Compositions containing 0.1, 0.2, 0.5, 1, 5 and 10 wt% of Socal 312 and 10 wt% of Socal U1S2 were analyzed. Furthermore, extruded and non-extruded PA12 were compared. NPCC was characterized through BET analysis (Brunauer, Emmett and Teller), which confirmed that Socal 312 had a specific surface area superior to Socal U1S2. Scanning electron microscopy revealed a tendency of the particles to agglomerate at 1 wt% NPCC and higher. However, all samples showed good distribution of the filler throughout the matrix. Differential Scanning Calorimetry (DSC) analyses did not show differences in the melting temperature of the compositions. Crystallization temperature tends to increase as the amount of filler in the matrix increases. Crystallinity degree showed differences only when comparing extruded and non-extruded PA12, the same occurs with Socal 312 in relation to Socal U1S2 containing 10 wt% of filler. Thermogravimetric analysis (TGA) showed that for contents from 0.5 wt% NPCC, increasing NPCC content reduces the thermal stability of the material. Muffle calcination tests confirmed the residues content obtained with TGA at 5 wt% NPCC higher, and evidenced good distribution of the filler along the specimen. Tensile and flexural strength and tensile and flexural modulus started increasing at 1 wt% NPCC and HDT started increasing at 0.2 wt% NPCC, showing the reinforcing effect of nanofiller and the increase in stiffness of the materials. Impact strength at 23 °C decreased at 0.5 wt% NPCC. Impact strength at -40 °C reduced only with addition of 10 wt% NPCC. Strain at break, toughness and impact strength at 23 °C showed reduction in extruded PA12 when compared to non-extruded PA12, possibly because extrusion favors the increase in crystallinity, as verified in the DSC analysis. Socal U1S2 also showed differences in relation to Socal 312 in strain at break, flexural modulus and HDT, probably due to its lower specific surface area in relation to Socal 312. Therefore, the incorporation of 1 wt% NPCC in PA12, already allows to obtain a nanocomposite with greater mechanical strength compared to neat PA12, which can be a feasible alternative for applications where an increase in mechanical properties is desired

scholarly journals Investigation on the Deterioration Mechanism of Recycled Plaster

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Zhixin Li ◽  
Kaidong Xu ◽  
Jiahui Peng ◽  
Jina Wang ◽  
Xianwei Ma ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Diameter ◽  
Nitrogen Adsorption ◽  
Water Requirement ◽  
Scanning Calorimetry ◽  
Average Pore ◽  
Preparation Temperature ◽  
Deterioration Mechanism

The deterioration mechanism of recycled plaster (R-P) was studied. The large specific surface area (SSA), improper preparation temperature, increased water requirement of R-P, and microstructure of its hardened body were analyzed by particle size distribution (PSD), Blaine method, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and nitrogen adsorption porosimetry. The results indicated that the properties of R-P were deteriorated, but its strength decreases from 50% at the same manufacturing process to 30%–40% at similar specific surface area. The analysis shows that the large SSA, poor morphology, narrow PSD, and increased internal detects give rise to increase of water requirement. In addition, the deterioration properties are caused by unsuitable temperature of preparation, loose structure, and large average pore diameter in hardened R-P as well.

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