scholarly journals Morphology and thermal stability of bacterial cellulose/collagen composites

2014 ◽  
Vol 12 (9) ◽  
pp. 968-975 ◽  
Author(s):  
Mădălina Albu ◽  
Zina Vuluga ◽  
Denis Panaitescu ◽  
Dumitru Vuluga ◽  
Angela Căşărică ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Bacterial Cellulose ◽  
Freeze Drying ◽  
Collagen Gel ◽  
Positive Influence ◽  
Mechanical Tests ◽  
Mechanical And Thermal Properties ◽  
Force Microscopy ◽  
Collagen Solution ◽  
Thermal Stability Of

AbstractThe aim of this paper was to prepare composites of bacterial cellulose (BC) and collagen to evaluate both the effect of collagen on the morphological, mechanical and thermal properties of BC and the effect of BC on the thermal stability of collagen for designing composites with increased potential biomedical applications. Two series of composites were prepared, the first series by immersing BC pellicle in solutions of collagen obtained in three forms, collagen gel (CG), collagen solution (CS) and hydrolysed collagen (HC), followed by freeze drying; and the second series of composites by mixing BC powder in solutions of collagen (CG, CS and HC), also followed by freeze drying. The properties of obtained composites were evaluated by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), mechanical tests, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results revealed that BC acts as a thermal stabilizer for CS matrix, while with CG matrix it interacts synergistically leading to composites with improved properties. On the other hand, the BC sheet impregnated with collagen has a significantly improved thermal stability. Collagen (as HC, CS or CG) has also a positive influence on the mechanical properties of lyophilized BC sheet. A four times increase of modulus was observed in BC/HC and BC/CG composites. and an increase of 60 times for BC/CS. The spectacular increase of elastic modulus and tensile strength in the case of BC/CS composite was explained by the easier penetration of collagen solution in the BC network and impregnation of BC fibrils as revealed by SEM and AFM analyzes.

Influence of trisilanol isooctyl POSS content on the structure, morphology and rheological properties of thermoplastic polyurethane (TPU)

2020 ◽  
Vol 40 (9) ◽  
pp. 727-735
Author(s):  
Rudinei Fiorio ◽  
Chaitanya Danda ◽  
João Maia
Keyword(s):  
Thermal Stability ◽  
Rheological Properties ◽  
Thermoplastic Polyurethane ◽  
Reactive Extrusion ◽  
Strain Rates ◽  
Force Microscopy ◽  
Atomic Force ◽  
Extensional Strain ◽  
Oligomeric Silsesquioxane ◽  
Thermal Stability Of

AbstractIn this study, thermoplastic polyurethanes (TPUs) containing trisilanol isooctyl polyhedral oligomeric silsesquioxane (POSS), a reactive nanofiller, were synthesized and characterized rheologically and morphologically, and the effects of POSS content on the melt thermal stability of the TPUs are investigated. Samples containing 0, 0.23, 0.57, 1.14, and 2.23% (w/w) POSS were synthesized by reactive extrusion and characterized by Fourier transform infrared spectroscopy (FTIR), oscillatory and extensional rheometry, atomic force microscopy (AFM), and small- and wide-angle X-ray scattering (SAXS and WAXS, respectively). The rheological properties of molten TPU are time-dependent and the melt thermal stability of the TPU is maximal at 1.14% of POSS. The addition of 0.23 and 0.57% POSS promotes strain-hardening at low extensional strain rates (0.01 and 0.10 s−1), not affecting the extensional characteristics at higher strain rates. The addition of increasing amounts of POSS leads to the formation of POSS-rich clusters well dispersed in the TPU matrix. SAXS and WAXS results show that the POSS domains are amorphous and that POSS does not modify the crystalline structure of TPU. Therefore, this work indicates that synthesizing TPU in the presence of trisilanol isooctyl POSS can increase the melt thermal stability of the polymer, facilitating its processing.

Morphology, Mechanical and Thermal Properties of Poly(Lactic Acid)/Propylene-Ethylene Copolymer/Cellulose Composites

2019 ◽  
Vol 972 ◽  
pp. 172-177
Author(s):  
Sirirat Wacharawichanant ◽  
Patteera Opasakornwong ◽  
Ratchadakorn Poohoi ◽  
Manop Phankokkruad
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Tensile Stress ◽  
Cellulose Fibers ◽  
Phase Morphology ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Ethylene Copolymer ◽  
Thermal Stability Of

This work studied the effects of various types of cellulose fibers on the morphology, mechanical and thermal properties of poly(lactic acid) (PLA)/propylene-ethylene copolymer (PEC) (90/10 w/w) blends. The PLA/PEC blends before and after adding cellulose fibers were prepared by melt blending method in the internal mixer and molded by compression method. The morphological analysis observed that the presence of cellulose in PLA did not change the phase morphology of PLA, and PLA/cellulose composite surfaces were observed the cellulose fibers inserted in PLA matrix and fiber pull-out. The phase morphology of PLA/PEC blends was changed from brittle fracture to ductile fracture behavior and showed the phase separation between PLA and PEC phases. The presence of celluloses did not improve the compatibility between PLA and PEC phases. The tensile stress and strain curves found that the tensile stress of PLA was the highest value. The addition of all celluloses increased Young’s modulus of PLA. The PEC presence increased the tensile strain of PLA over two times when compared with neat PLA and PLA was toughened by PEC. The incorporation of cellulose fibers in PLA/PEC blends could improve Young’s modulus, tensile strength, and stress at break of the blends. The thermal stability showed that the degradation temperatures of all types of cellulose were less than the degradation temperatures of PLA. Thus, the incorporation of cellulose in PLA could not enhance the thermal stability of PLA composites and PLA/PEC composites. The degradation temperature of PEC was the highest value, but it could not improve the thermal stability of PLA. The incorporation of cellulose fibers had no effect on the melting temperature of the PLA blend and composites.

Morphology and Properties of Poly(Lactic Acid)/Ethylene-Octene Copolymer Blends with Different Organoclay Types

2020 ◽  
Vol 837 ◽  
pp. 174-180
Author(s):  
Sirirat Wacharawichanant ◽  
Attachai Sriwattana ◽  
Kulaya Yaisoon ◽  
Manop Phankokkruad
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Two Phase ◽  
Copolymer Blends ◽  
Ethylene Octene Copolymer ◽  
Surface Modified ◽  
Thermal Stability Of ◽  
Observation Results

This work studied the morphology, mechanical and thermal properties of poly (lactic acid) (PLA)/ethylene-octene copolymer (EOC) (80/20) blends with different organoclay types. Herein, EOC was introduced to toughening PLA by melt blending and organoclay was used to improve compatibility and tensile properties of the blends. The two organoclay types were nanoclay surface modified with aminopropyltriethoxysilane 0.5-5 wt% and octadecylamine 15-35% (Clay-ASO) and nanoclay surface modified with dimethyl dialkyl (C14-C18) amine 35-45 wt% (Clay-DDA). The organoclay contents were 3, 5 and 7 phr. Scanning electron microscope (SEM) observation results revealed PLA/EOC blends demonstrated a two-phase separation of dispersed EOC phase and PLA matrix phase. The addition of organoclay significantly improved the compatibility between PLA and EOC phases due to EOC droplet size decreased dominantly in PLA matrix, so organoclay could act as an effective compatibilizer. The incorporation of organoclay increased significantly tensile strength of PLA/EOC/organoclay composites while Young’s modulus increased with 5 phr of organoclay. The thermal stability of PLA/EOC blends did not change when compared with neat PLA, and when added Clay-ASO in the blends could improve the thermal stability of the PLA/EOC blends.

scholarly journals Effect of Modification with Various Epoxide Compounds on Mechanical, Thermal, and Coating Properties of Epoxy Resin

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Alaaddin Cerit ◽  
Mustafa Esen Marti ◽  
Ulku Soydal ◽  
Suheyla Kocaman ◽  
Gulnare Ahmetli
Keyword(s):  
Thermal Stability ◽  
Atomic Force Microscopy ◽  
Tensile Strength ◽  
Epoxy Resin ◽  
Curing Process ◽  
Coating Properties ◽  
Corrosive Media ◽  
Force Microscopy ◽  
Atomic Force ◽  
Thermal Stability Of

Epoxy resin (ER) was modified with four different epoxide compounds, 4,5-epoxy-4-methyl-pentane-2-on (EMP), 3-phenyl-1,2-epoxypropane (PhEP), 1-chloro-2,3-epoxy-5-(chloromethyl)-5-hexene (CEH), and a fatty acid glycidyl ester (FAGE), to improve its chemical and physical properties. The effects of the addition and amount of these modifiers on mechanical, thermal, and coating properties were investigated. Atomic force microscopy was used to observe the changes obtained with the modification. The influence of the modifying agents on the curing process was monitored through FTIR spectroscopy. The curing degrees of ER and modified ERs (M-ERs) were found to be over 91%. The results showed that tensile strength of ER improved till 30% (wt.) with addition of the modifier content. Modification with EMP and PhEP remarkably enhanced the thermal stability of ER to be highly resistant to the corrosive media.

Thermal stability of nanocrystalline CeO2 prepared through freeze drying

2010 ◽  
Vol 46 (1) ◽  
pp. 43-46 ◽  
Author(s):  
V. K. Ivanov ◽  
O. S. Polezhaeva ◽  
A. E. Baranchikov ◽  
A. B. Shcherbakov
Keyword(s):  
Thermal Stability ◽  
Freeze Drying ◽  
Thermal Stability Of

scholarly journals Enhancing the Thermal Stability of Ionogels: Synthesis and Properties of Triple Ionic Liquid/Halloysite/MCC Ionogels

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6198
Author(s):  
Olga V. Alekseeva ◽  
Valeriya D. Shibaeva ◽  
Andrew V. Noskov ◽  
Vladimir K. Ivanov ◽  
Alexander V. Agafonov
Keyword(s):  
Thermal Stability ◽  
Ionic Liquid ◽  
Glass Transition ◽  
Mechanical Characteristics ◽  
Interlayer Space ◽  
Xrd Analysis ◽  
Mechanical Tests ◽  
Water Molecules ◽  
Residual Water ◽  
Thermal Stability Of

In this study, an ionic liquid (IL), 1-butyl-3-methylimidazolium acetate, was used to prepare ionogels with microcrystalline cellulose (MCC) and halloysite (Hal). SEM, XRD, TG, DSC, FTIR spectroscopy, conductometry and mechanical tests were used to study the morphology, structure, thermal behaviour and electrophysical and mechanical characteristics of synthesised ionogels. XRD analysis showed a slight decrease in the interlayer space of halloysite in ionogels containing MCC, which may have been associated with the removal of residual water molecules resulting from hydrophilic IL anions and polymer macromolecules. A change in conductivity and glass-transition temperature of the ionic liquid was revealed due to intercalation into halloysite (a confinement effect) and modification with cellulose. For triple IL/Hal/MCC ionogels, the characteristic thermal degradation temperatures were higher than the corresponding values for IL/Hal composites. This indicates that the synthesised IL/Hal/MCC ionogels are characterised by a greater thermal stability than those of IL/Hal systems.

scholarly journals Upcycling of Waste Polyethylene and Cement Kiln Dust to Produce Polymeric Composite Sheets Using Gamma Irradiation

2021 ◽  
Author(s):  
Ehab Khozemy ◽  
Hamdi Radi ◽  
Nabila A Mazied
Keyword(s):  
Thermal Stability ◽  
Gamma Irradiation ◽  
Cement Kiln Dust ◽  
Cement Kiln ◽  
Mechanical And Thermal Properties ◽  
Rubber Industry ◽  
Waste Polyethylene ◽  
Prepared Composite ◽  
Kiln Dust ◽  
Thermal Stability Of

Abstract Cement kiln dust (CKD) is a residue produced during the manufacture of cement that contains hazardous solid waste of high toxicity that affects the environment and public health. In this study, the possibility of using cement waste as a filler in the plastic and rubber industry was studied. Different concentrations of (CKD) and gamma irradiation on the mechanical, thermal stability of the prepared composites sheets were investigated. Different concentrations of (CKD) 10, 15, 20, 30, 35, and 40 wt % were prepared with double screw extrusion by mixing waste polyethylene (WPE), de-vulcanized rubber (DWR), and EPDM rubber. These prepared composites were irradiated with doses 25, 50, 75, 100, and 150 kGy to study the effect of radiation on the physical, mechanical properties, and thermal stability of the prepared composite sheets. The prepared composite sheets were characterized and verified by FTIR and soluble fractions. The morphology of the composite sheets was investigated by SEM. Mechanical and thermal properties were investigated to evaluate the possibility of its application in the plastic and rubber industry.

Effect of Incorporating ZrO2 Nanoparticles on Mechanical and Thermal Stability of Polymer Blends

2021 ◽  
Vol 19 (5) ◽  
pp. 104-113
Author(s):  
Mena M. Husein ◽  
Seenaa I. Hussein
Keyword(s):  
Thermal Stability ◽  
Wear Resistance ◽  
Polymer Blends ◽  
Mechanical Tests ◽  
Zro2 Nanoparticles ◽  
Casting Method ◽  
Polymeric Blends ◽  
Oil Pipelines ◽  
Oil Tanks ◽  
Thermal Stability Of

In this study, polymeric blends were developed by incorporating nano ZrO2 in the polymer blend with applications to oil tanks. The samples of tanks from the oil pipelines company of the Dora refinery in Baghdad. The blend and Nanocomposites preparation using casting method, the ratio of ZrO2 nano (0, 1, 3, 5, and 7 wt%). The results showed the mechanical tests, the best ratio of hardness 3 wt% with (71.93) and 3 wt% with Abrasion wear resistance the (2.4×10-7) compared with another ratio. The Adhesion strength of pure (2.31) MPa and the best ratio of 1 wt% (8.39) MPa. The current work confirms the thermal stability of the nanocomposites increases gradually with increasing the percentage of ZrO2 compared to the blend without adding ZrO2 nano and this is due to the thermal resistance of the ZrO2 nano.

Interactions, morphology and thermal stability of graphene-oxide reinforced polymer aerogels derived from star-like telechelic aldehyde-terminal benzoxazine resin

RSC Advances ◽  
2015 ◽  
Vol 5 (112) ◽  
pp. 92719-92731 ◽  
Author(s):  
Almahdi A. Alhwaige ◽  
Saeed M. Alhassan ◽  
Marios S. Katsiotis ◽  
Hatsuo Ishida ◽  
Syed Qutubuddin
Keyword(s):  
Thermal Stability ◽  
Graphene Oxide ◽  
Freeze Drying ◽  
Reinforced Polymer ◽  
Thermal Stability Of

Graphene oxide (GO)-reinforced nanocomposite aerogels of polybenzoxazine preparedviafreeze-drying of GO suspensions in benzoxazine precursor solutions have been studied.

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