Effect of Silica Size on the Thermal, Mechanical and Biodegradable Properties of Polylactide/Silica Composite Material Prepared by Melt Blending

2010 ◽  
Vol 123-125 ◽  
pp. 1215-1218 ◽  
Author(s):  
Tsao Cheng Huang ◽  
Jui Ming Yeh ◽  
Jen Chang Yang
Keyword(s):  
Composite Material ◽  
Mechanical Strength ◽  
Silica Particle ◽  
Sol Gel ◽  
Average Diameter ◽  
Mechanical Analysis ◽  
Silica Particles ◽  
Scanning Calorimetry ◽  
Twin Screw ◽  
Biodegradable Properties

In this study, we attempt to investigate the effect of silica size on the thermal, mechanical and biodegradable properties of polylactide/amino-silica (PLA/SiO2) composite material, by preparing the PLA/ SiO2 hybrids containing different size of silica particle through twin-screw extruder. First of all, we prepared amino-functionalized silica particles through performing the conventional base-catalyzed sol-gel reaction of methyltrimethoxysilane (MTMS) and 3-aminopropyltrimethoxysilane (APTMS). The average diameter of silica particle employed in hybrids was 150 nm (S-silica) and 1μm (B-silica), respectively. Systematically comparative studies on the thermal properties and mechanical strength of hybrids containing two different sizes of SiO2 particles materials were carried out on a basis of studies of thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). It should be noted that the mechanical strength of hybrids containing smaller size of silica particles was found to reveal significant improvement in storage modulus as compared to its corresponding counterpart based on the DMA investigation. Moreover, the thermal stability of hybrids containing smaller size of silica particles was found to reveal slight improvement in glass transition temperature as compared to its corresponding counterpart based on the DSC investigation. Eventually, the as-prepared hybrids were found to exhibit almost similar degradation behavior to that of neat PLA.

Development and Mechanical Characterization of a Collagen/Hydroxyapatite Bilayered Scaffold for Ostechondral Defect Replacement

2011 ◽  
Vol 493-494 ◽  
pp. 890-895 ◽  
Author(s):  
Francesca Gervaso ◽  
Francesca Scalera ◽  
Sanosh Kunjalukkal Padmanabhan ◽  
Antonio Licciulli ◽  
Daniela Deponti ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Sol Gel ◽  
Three Dimensional ◽  
Collagen Scaffold ◽  
Mechanical Analysis ◽  
Design Parameters ◽  
Compression Tests ◽  
Templating Method ◽  
Organic Part ◽  
Hydroxyapatite Scaffold

In this work a novel three-dimensional ostechondral substitute is proposed that is made of an inorganic/organic hybrid material, namely collagen/hydroxyapatite. The two components of the substitute have been characterized separately. The inorganic part, a hydroxyapatite scaffold, was fabricated by a polymer sponge templating method using a reactive sub-micron powder synthesized in our laboratory by hydroxide precipitation sol-gel route. The organic part, a collagen scaffold, was fabricated by a freeze-dying technique varying design parameters. Both the parts were analysed by scanning electron microscopy and their mechanical properties assessed by compression tests. The hydroxyapatite scaffold showed a high and highly interconnected porosity and a mechanical strength equal to 0.55 MPa, higher than those reported in literature. The collagen scaffolds were seeded by chondrocytes, processed for histology analysis and tested in compression. The biological tests proved the ability of the scaffolds to be positively populated by chondrocytes and the mechanical analysis showed that the mechanical strength of the scaffolds significantly increased after 3 weeks of culture.

scholarly journals Mechanical Strength Enhancement of Polylactic Acid Hybrid Composites

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 349 ◽  
Author(s):  
Ji-Won Park ◽  
Jae-Ho Shin ◽  
Gyu-Seong Shim ◽  
Kyeng-Bo Sim ◽  
Seong-Wook Jang ◽  
...  
Keyword(s):  
Composite Material ◽  
Mechanical Strength ◽  
Polylactic Acid ◽  
Mechanical Performance ◽  
Natural Fiber ◽  
Hybrid Composites ◽  
Structural Characteristics ◽  
Scanning Calorimetry ◽  
Environmental Friendliness ◽  
Research Attention

In recent years, there has been an increasing need for materials that are environmentally friendly and have functional properties. Polylactic acid (PLA) is a biomass-based polymer, which has attracted research attention as an eco-friendly material. Various studies have been conducted on functionality imparting and performance improvement to extend the field of application of PLA. Particularly, research on natural fiber-reinforced composites have been conducted to simultaneously improve their environmental friendliness and mechanical strength. Research interest in hybrid composites using two or more fillers to realize multiple functions are also increasing. Phase change materials (PCMs) absorb and emit energy through phase transition and can be used as a micro encapsulated structure. In this study, we fabricated hybrid composites using microcapsulated PCM (MPCM) and the natural fibrous filler, kenaf. We aimed to fabricate a composite material with improved endothermic characteristics, mechanical performance, and environmental friendliness. We analyzed the endothermic properties of MPCM and the structural characteristics of two fillers and finally produced an eco-friendly composite material. The PCM and kenaf contents were varied to observe changes in the performance of the hybrid composites. The endothermic properties were determined through differential scanning calorimetry, whereas changes in the physical properties of the hybrid composite were determined by measuring the mechanical properties.

Toughening Modification of Poly(butylene terephthalate)/Polycarbonate Blends by Poly(ethylene-co-octene)

2005 ◽  
Vol 13 (4) ◽  
pp. 385-394
Author(s):  
Huiyu Bai ◽  
Yong Zhang ◽  
Yinxi Zhang ◽  
Xiangfu Zhang ◽  
Wen Zhou
Keyword(s):  
Average Diameter ◽  
Melt Blending ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Bisphenol A Polycarbonate ◽  
Elongation At Break ◽  
Butylene Terephthalate ◽  
Twin Screw ◽  
Poly Ethylene ◽  
The Impact

New toughened poly(butylene terephthalate) (PBT)/bisphenol A polycarbonate (PC) blends were obtained by melt blending with commercial poly(ethylene-co-octene) copolymer (POE), varying the POE content up to 10 wt%, in a twin screw extruder, followed by injection moulding. The influence of POE on the properties of the PBT/PC blends was investigated in terms of mechanical testing, dynamic mechanical thermal (DMTA) analysis, differential scanning calorimetry (DSC), and scanning electronic microscopy (SEM). The results showed that addition of POE led to remarkable increases in the impact strength, elongation at break and Vicat temperature, and a reduction in the tensile strength and flexural properties of PBT/PC blends. The morphology of the blends was observed using SEM and the average diameter of the dispersed phase was determined by image analysis. The critical inter-particle distance for PBT/PC was determined.

scholarly journals Mechanical and thermal properties of PP/PBT blends compatibilized with triblock thermoplastic elastomer

2015 ◽  
Vol 17 (3) ◽  
pp. 78-83 ◽  
Author(s):  
Wojciech Ignaczak ◽  
Kinga Wiśniewska ◽  
Jolanta Janik ◽  
Mirosława El Fray
Keyword(s):  
Triblock Copolymer ◽  
Thermoplastic Elastomer ◽  
Fold Increase ◽  
Mechanical Analysis ◽  
Mechanical And Thermal Properties ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Twin Screw ◽  
Copolymer Poly ◽  
Linear Triblock Copolymer

Abstract A linear triblock copolymer, poly(styrene-b-etylene/butylene-b-styrene)(SEBS) thermoplastic elastomer (TPE) grafted with maleic anhydride was used for compatibilization of PP/PBT blends. PP/PBT blends of different mass ratios 60/40, 50/50, 40/60 were mixed with 2.5, 5.0 and 7.5 wt.% of SEBS copolymer in a twin screw extruder. Differential scanning calorimetry and dynamic mechanical analysis were performed to define the phase structure of PP/PBT blends. TPE with a rubbery mid-block shifted the glass transition of PP/PBT blend towards lower temperatures, and significant decrease the crystallization temperature of a crystalline phase of PP component was observed. The influence of the amount of compatibilizer and the blend composition on the mechanical properties (tensile and flexural strengths, toughness and moduli) was determined. Addition of 5 wt.% of a triblock TPE led to a three-fold increase of PP/PBT toughness. A significant increase of impact properties was observed for all materials compatibilized with the highest amount of SEBS copolymer.

scholarly journals Preparation and Performance of Ultra-Fine Polypropylene Antibacterial Fibers via Melt Electrospinning

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 606 ◽  
Author(s):  
Qiu-Sheng Li ◽  
Hong-Wei He ◽  
Zuo-Ze Fan ◽  
Ren-Hai Zhao ◽  
Fu-Xing Chen ◽  
...  
Keyword(s):  
Antibacterial Agent ◽  
Average Diameter ◽  
Element Distribution ◽  
Raw Material ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Technical Textiles ◽  
Twin Screw ◽  
And Performance ◽  
Fourier Transfer Infrared Spectroscopy

Polypropylene (PP) fibers are employed commonly as the raw material of technical textiles (nonwovens), and the research focuses on fine-denier fibers and their functionalities. In this work, antibacterial PP masterbatches with different dosage (1–5 wt.%) of nano-ZnO particles as the antibacterial agent were prepared via a twin-screw extruder. The as-prepared PP masterbatches were electrospun on a home-made electrospinning device to afford ultra-fine PP fibers. The morphologies of as-spun ultrathin PP fibers with 16 μm of average diameter were observed by SEM. The structure and element distribution were characterized by means of energy-dispersive spectroscopy (EDS) and Fourier-transfer infrared spectroscopy (FTIR), respectively. There was some zinc obviously distributed on the surface when a dosage of ZnO more than 1 wt.% was used, which contributed to the antibacterial activity. The crystallinity of PP fibers was not affected strongly by the dosage of ZnO based on the differential scanning calorimetry (DSC) heating curves, while thermal decomposition improved with the increase in ZnO content, and the mechanical strength decreased predictably with the increase in inorganic ZnO content.

Preparation of Spherical Silica with Controllable Size

2018 ◽  
Vol 281 ◽  
pp. 65-70
Author(s):  
Shu Lin Wang ◽  
Zhao Wang ◽  
Bing Hao Li ◽  
Man Xu
Keyword(s):  
Particle Size ◽  
Silica Particle ◽  
Sol Gel ◽  
Silica Particles ◽  
Spherical Particles ◽  
Alkali Content ◽  
Spherical Silica ◽  
Hydrolysis Temperature ◽  
Spherical Silica Particles ◽  
Size And Morphology

The spherical silica particles were prepared by sol-gel method with TEOS as precursor, ethanol as solvent in the presence of ammonia. The effects of reaction temperature and the amount of ammonia and TEOS on the size and morphology of silica particles were investigated. The hydrolysis temperature , alkali and TEOS content does not affect the morphology of silica, the silica particles were spherical; With the increase of hydrolysis temperature, particle size of silica showed first increased and then decreased, when the hydrolysis temperature is 30 °C, the silica particle size up to 0.6 μm, when the hydrolysis temperature is 60 °C, the silica particle size is 0.15 μm; With the increase of the content of alkali, silica particle size showed first increased and then decreased, when the alkali content is 20 ml, the silica particle size up to 0.6 μm and when the alkali content is 10 ml, the silica particle size is 0.2 μm; With the increase of TEOS dosage, the amount of spherical silica increased and the particle size of silica spherical particles first increased and then decreased.

scholarly journals Preparation and Performance of Nano-hybrids Synthesized from Polyimide and Silica

2009 ◽  
Vol 2 (1) ◽  
pp. 99-107 ◽  
Author(s):  
S. M. M. Alam
Keyword(s):  
Sol Gel ◽  
Tensile Modulus ◽  
Mechanical Analysis ◽  
Hybrid Films ◽  
Scanning Calorimetry ◽  
Chemical Structures ◽  
Sol Gel Process ◽  
Biphenyltetracarboxylic Dianhydride ◽  
Silica Hybrid

Polyimide (PI)-inorganic like silica hybrid films were successfully prepared to combine the good performances of silica like tensile modulus, thermal stability etc. into organic PI. Polyamic acid (PAA), precursor of PI, was prepared from 3, 3′, 4, 4′-biphenyltetracarboxylic dianhydride (BPDA), p-phenylediamine (PDA) and in-situ formed silica was formed into PAA from tetraethoxysilane (TEOS) through in-situ sol-gel process. The films were transparent and became translucent in presence of up to 10% inorganic contents. The chemical structures were characterized by Fourier transform infrared spectroscopy (FTIR). The morphology of the films was investigated by scanning electronic microscopy (SEM). Differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), stress-strain tests and dynamic mechanical analysis (DMA) were used to evaluate the performances of the films. The results indicated that the glass-transition temperatures (Tg) and decomposition temperatures of the PI-silica hybrid films were higher than those of pristine PI. Tensile modulus, tensile strength of PI increased prominently in presence of small amount (1%) of silica in PI-silica hybrid. Keywords: Polyimide; Hybrid; Sol-gel process. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i1.2733                 J. Sci. Res. 2 (1), 99-107 (2010)  

Thermally stable and high impact toughness chopped PI fiber-reinforced PEEK composites

2019 ◽  
Vol 32 (6) ◽  
pp. 655-661
Author(s):  
Jianan Yao ◽  
Weizhou Yao ◽  
Yangyang Gu ◽  
Jindong Zhang ◽  
Youhai Yu ◽  
...  
Keyword(s):  
Tensile Modulus ◽  
Mold Temperature ◽  
Mechanical Analysis ◽  
Fiber Content ◽  
Fiber Reinforced ◽  
Scanning Calorimetry ◽  
Polyether Ether Ketone ◽  
Twin Screw ◽  
The Impact ◽  
The Relationship

Chopped polyimide (PI) fiber-reinforced polyether ether ketone (PEEK) composites with different fiber content (0%, 10%, 20%, and 30%) were prepared via melt extrusion using a twin-screw extruder. The impact strength of these composites significantly improved from 4.9 kJ m−2 to 9.3 kJ m−2 with the increase of the PI fiber content from 0% to 30%. Tensile strength, tensile modulus, and flexural strength also increased with the increase in PI fiber content. In addition, the heat deflection temperature increased significantly from 160°C to 318°C. The results of the dynamic mechanical analysis revealed that the storage modulus increased considerably. The relationship between mold temperature and composite properties was investigated, and using differential scanning calorimetry, it was shown that the increase in mold temperature improved the degree of polymer crystallization and the bonding capability of the fiber and resin interface. As a result, the mechanical properties of the composite material were improved.

A geopolymeric composite of non-calcined rice husks made of metakaolin/sol–gel silica

2018 ◽  
Vol 53 (5) ◽  
pp. 603-611 ◽  
Author(s):  
Coraquetzali Magdaleno-López ◽  
José de Jesús Pérez-Bueno ◽  
Juan Carlos Flores-Segura ◽  
José Luis Reyes-Araiza ◽  
Maria Luisa Mendoza-López ◽  
...  
Keyword(s):  
Composite Material ◽  
Laser Scanning ◽  
Construction Material ◽  
Sol Gel ◽  
Visible Spectrum ◽  
Industrial Wastes ◽  
Rice Husks ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

In this work, the development of a composite material with geopolymer and a high content of rice husks without heat treatment was investigated to create and characterize a low-cost composite made with agro-industrial wastes. The ratio used was about 12/88 wt./% of sol–gel and metakaolin related to rice husks. This kind of composite geopolymer was designed as both a construction material for load or aesthetic finishing. X-ray diffraction studies reveal that the composite has an amorphous phase and a crystalline one, which is typical of geopolymeric materials. The scanning electron microscopy showed that the geopolymeric matrix completely wrapped the rice husks. The composite material has a compressive strength close to some mortars with a value of about 110 kg/cm2 (10.8 MPa). Laser scanning confocal microscopy reveals that there is a difference of emission in the visible spectrum between the inner and outer sides of the rice husks, which corroborates that they have a different chemical composition. Differential scanning calorimetry analysis confirmed that the composite material has combined characteristics of its raw materials. X-ray diffraction studies show that metakaolin with sol–gel solutions had temperature-dependent interactions besides that, after the dehydroxylation, the composite material is mostly amorphous. The material of high content of rice husk bound by geopolymer could be applicable in various areas of the construction industry and finishing.

scholarly journals Extruded PLA Nanocomposites Modified by Graphene Oxide and Ionic Liquid

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 655
Author(s):  
Cristian Sánchez-Rodríguez ◽  
María-Dolores Avilés ◽  
Ramón Pamies ◽  
Francisco-José Carrión-Vilches ◽  
José Sanes ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Graphene Oxide ◽  
Viscoelastic Behavior ◽  
Mechanical Analysis ◽  
Twin Screw Extrusion ◽  
Scanning Calorimetry ◽  
Screw Extrusion ◽  
Ir And Raman Spectroscopies ◽  
Twin Screw ◽  
Ft Ir

Polylactic acid (PLA)-based nanocomposites were prepared by twin-screw extrusion. Graphene oxide (GO) and an ionic liquid (IL) were used as additives separately and simultaneously. The characterization of the samples was carried out by means of Fourier transform infrared (FT-IR) and Raman spectroscopies, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The viscoelastic behavior was determined using dynamic mechanical analysis (DMA) and rheological measurements. IL acted as internal lubricant increasing the mobility of PLA chains in the solid and rubbery states; however, the effect was less dominant when the composites were melted. When GO and IL were included, the viscosity of the nanocomposites at high temperatures presented a quasi-Newtonian behavior and, therefore, the processability of PLA was highly improved.

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