A study of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) biofilms’ thermal and biodegradable properties reinforced with halloysite nanotubes

2018 ◽  
Vol 52 (23) ◽  
pp. 3199-3207 ◽  
Author(s):  
SM Kamrul Hasan ◽  
S Zainuddin ◽  
J Tanthongsack ◽  
MV Hosur ◽  
L Allen
Keyword(s):  
Petroleum Products ◽  
Halloysite Nanotubes ◽  
Synthetic Polymers ◽  
Soil Conditions ◽  
Solvent Casting ◽  
Casting Method ◽  
Scanning Calorimetry ◽  
Structural Applications ◽  
Biodegradation Process ◽  
Biodegradable Properties

The aim of this study is to investigate and optimize the performance of a promising biopolymer, poly (3-hydroxybutyrate-co-3-hydroxyvalerate) which can potentially replace non-biodegradable synthetic polymers derived from toxic petroleum products. Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) biofilms were prepared using solvent casting method, and its thermal properties were determined using thermogravimetric and differential scanning calorimetry techniques. Also, the durability and biodegradability of these films were studied by keeping the samples in water and Alabama soil conditions for various lengths of time. Our results showed that the thermal and moisture resistance of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) biopolymer can be enhanced significantly with the addition of low halloysite nanotubes concentrations. Also, the biodegradation process of the poly (3-hydroxybutyrate-co-3-hydroxyvalerate) films was faster with the addition of halloysite nanotubes attributed to the accelerated microbial microorganism reaction in the soil. This study led to cognize that the PHBV biopolymers added with halloysite nanotubes can be successfully used for various biomedical, industrial and structural applications, and then decompose at a desired faster rate afterward.

scholarly journals FORMULATION AND EVALUATION OF FAST DISSOLVING FILMS OF ELETRIPTAN HYDROBROMIDE

2017 ◽  
Vol 9 (2) ◽  
pp. 59
Author(s):  
K. Pallavi ◽  
T. Pallavi
Keyword(s):  
Drug Release ◽  
Xanthan Gum ◽  
Guar Gum ◽  
Methyl Cellulose ◽  
Synthetic Polymers ◽  
Locust Bean Gum ◽  
Solvent Casting ◽  
Casting Method ◽  
Disintegration Time ◽  
Locust Bean

Objective: The main aim of the present research was to develop an oral fast dissolving polymeric film (FDF) with good mechanical properties, faster disintegration and dissolution when placed on the tongue.Methods: Eletriptan hydrobromide is prescribed for the treatment of mild to a moderate migraine. The polymers selected for preparing films were Pullulan, Maltodextrin (MDX), Acacia, Sodium alginate (SA), Locust bean gum (LBG), Guar gum (GG), Xanthan gum (XG), Polyvinyl alcohol (PVA), Polyvinyl pyrrolidine (PVP), Hydroxyl propyl methyl cellulose (HPMC) E5, and HPMC E15. Twelve sets of films FN1–FN12 were prepared by solvent casting method with Pullulan and combination of Acacia, MDX, SA, LBG, GG, XG, PVA, PVP, HPMC E5 and HPMC E15. Five sets of films FS1–FS5 were prepared using synthetic polymers like PVA, PVP, HPMC E5 and HPMC E15.Results: From all the prepared polymer formulations, FN2, FN8, and FS3 were selected based on disintegration time, and drug release and amongst this three FN2 was optimised based on its disintegration time (D. T). The percent drug release of the optimised film was compared with the percent release of the pure drug.Conclusion: The optimised formulation had a D. T of 16 s and a percent drug release of 97.5% in 10 min in pH 6.8 phosphate buffer and 100.6% drug release in 10 min in 0.1N HCl.

APPLICATIONS OF CHITOSAN-SULFATHIAZOLE AS ANTIMICROBIAL AGENT

2018 ◽  
Vol 28 (2) ◽  
pp. 429-432
Author(s):  
Dilyana Zvezdova
Keyword(s):  
Wound Healing ◽  
Antibacterial Activity ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Antimicrobial Agent ◽  
Defense Mechanisms ◽  
Solvent Casting ◽  
Casting Method ◽  
Gram Negative ◽  
Positively Charged

Chitosan, a hydrophilic biopolymer industrially obtained by N-deacetylation of chitin, can be applied as an antimicrobial agent. It highlights the applications of chitosan as an antimicrobial agent against fungi, bacteria, and viruses and as an elicitor of plant defense mechanisms. A series of novel chitosan-sulfathiazole nanocomposite (CSFZ) films were prepared by using solvent casting method for wound healing application. Fourier transform infrared spectroscopy (FTIR) was employed to ascertain the interaction between negatively charged sulfathiazole and positively charged chitosan. Moreover, the antibacterial activity of the films was investigated against gram positive and gram negative microorganisms. It was found that all CSFZ films showed good inhibitory activity against all the tested bacteria as compared to control. The above analysis suggested that the CSFZ films could be used as potential candidates for wound healing application.

Effect of Polyethylene Glycol in Nanocellulose/PLA Composites

2019 ◽  
Vol 821 ◽  
pp. 89-95
Author(s):  
Wanasorn Somphol ◽  
Thipjak Na Lampang ◽  
Paweena Prapainainar ◽  
Pongdhorn Sae-Oui ◽  
Surapich Loykulnant ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Lactic Acid ◽  
Polyethylene Glycol ◽  
Aspect Ratio ◽  
Mechanical Performance ◽  
Tensile Modulus ◽  
Poly Lactic Acid ◽  
Solvent Casting ◽  
Casting Method ◽  
Mediated Oxidation

Poly (lactic acid) or PLA was reinforced by nanocellulose and polyethylene glycol (PEG), which were introduced into PLA matrix from 0 to 3 wt.% to enhance compatibility and strength of the PLA. The nanocellulose was prepared by TEMPO-mediated oxidation from microcrystalline cellulose (MCC) powder and characterized by TEM, AFM, and XRD to reveal rod-like shaped nanocellulose with nanosized dimensions, high aspect ratio and high crystallinity. Films of nanocellulose/PEG/PLA nanocomposites were prepared by solvent casting method to evaluate the mechanical performance. It was found that the addition of PEG in nanocellulose-containing PLA films resulted in an increase in tensile modulus with only 1 wt% of PEG, where higher PEG concentrations negatively impacted the tensile strength. Furthermore, the tensile strength and modulus of nanocellulose/PEG/PLA nanocomposites were higher than the PLA/PEG composites due to the existence of nanocellulose chains. Visual traces of crazing were detailed to describe the deformation mechanism.

scholarly journals Microstructural Characterization and Mechanical Property of Al-Li Plate Produced by Centrifugal Casting Method

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 966
Author(s):  
Qingle Tian ◽  
Kai Deng ◽  
Zhishuai Xu ◽  
Ke Han ◽  
Hongxing Zheng
Keyword(s):  
Centrifugal Casting ◽  
High Strength ◽  
Microstructural Characterization ◽  
Fracture Morphology ◽  
Total Elongation ◽  
Mechanical Anisotropy ◽  
Tensile Fracture ◽  
Casting Method ◽  
Scanning Calorimetry ◽  
Strengthening Phases

Using a centrifugal casting method, along with deformation and aging, we produced a high-strength, low-anisotropy Al-Li plate. The electron probe microanalysis, transmission electron microscope, differential scanning calorimetry, and X-ray diffraction were used to clarify the evolution of strengthening phases. Experimental results showed that centrifugal-cast Al-Li plate consisted of intragrain δ′—(Al,Cu)3Li precipitate and interdendritic θ′—Al2Cu particles. After cold-rolling to a reduction ratio of 60% and annealing at 800 K for 90 min, both primary θ′ and δ′ were dissolved in solid solution. Aging at 438 K for 60 h led to the formation of two kinds of precipitates (needle-like T1—Al2CuLi and spherical δ′ in two sizes), which acted as the main strengthening phases. The average values of ultimate tensile strength and yield strength for the anneal-aged plate reached 496 MPa and 408 MPa, with a total elongation of 3.9%. The anneal-aged plate showed mechanical anisotropy of less than 5%. The tensile fracture morphology indicated a typical intergranular fracture mode.

scholarly journals Isothermal Vulcanization and Non-Isothermal Degradation Kinetics of XNBR/Epoxy/XNBR-g-Halloysite Nanotubes (HNT) Nanocomposites

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2872
Author(s):  
Seyed Mohamad Reza Paran ◽  
Ghasem Naderi ◽  
Elnaz Movahedifar ◽  
Maryam Jouyandeh ◽  
Krzysztof Formela ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Degradation Kinetics ◽  
Halloysite Nanotubes ◽  
Butadiene Rubber ◽  
Order Model ◽  
Scanning Calorimetry ◽  
Theoretical Methods ◽  
Vulcanization Kinetics ◽  
Kinetics Of ◽  
Thermal Stability Of

The effect of several concentrations of carboxylated nitrile butadiene rubber (XNBR) functionalized halloysite nanotubes (XHNTs) on the vulcanization and degradation kinetics of XNBR/epoxy compounds were evaluated using experimental and theoretical methods. The isothermal vulcanization kinetics were studied at various temperatures by rheometry and differential scanning calorimetry (DSC). The results obtained indicated that the nth order model could not accurately predict the curing performance. However, the autocatalytic approach can be used to estimate the vulcanization reaction mechanism of XNBR/epoxy/XHNTs nanocomposites. The kinetic parameters related to the degradation of XNBR/epoxy/XHNTs nanocomposites were also assessed using thermogravimetric analysis (TGA). TGA measurements suggested that the grafted nanotubes strongly enhanced the thermal stability of the nanocomposite.

scholarly journals Halloysite Nanotubes and Silane-Treated Alumina Trihydrate Hybrid Flame Retardant System for High-Performance Cable Insulation

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2134
Author(s):  
Sandra Paszkiewicz ◽  
Izabela Irska ◽  
Iman Taraghi ◽  
Elżbieta Piesowicz ◽  
Jakub Sieminski ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polymer Blend ◽  
Hybrid System ◽  
Reference Sample ◽  
Melt Flow Index ◽  
Halloysite Nanotubes ◽  
Flow Index ◽  
Scanning Calorimetry ◽  
Limiting Oxygen Index ◽  
Alumina Trihydrate

The effect of the presence of halloysite nanotubes (HNTs) and silane-treated alumina trihydrate (ATH-sil) nanofillers on the mechanical, thermal, and flame retardancy properties of ethylene-vinyl acetate (EVA) copolymer/low-density polyethylene (LDPE) blends was investigated. Different weight percentages of HNT and ATH-sil nanoparticles, as well as the hybrid system of those nanofillers, were melt mixed with the polymer blend (reference sample) using a twin-screw extruder. The morphology of the nanoparticles and polymer compositions was studied using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The mechanical properties, hardness, water absorption, and melt flow index (MFI) of the compositions were assessed. The tensile strength increases as a function of the amount of HNT nanofiller; however, the elongation at break decreases. In the case of the hybrid system of nanofillers, the compositions showed superior mechanical properties. The thermal properties of the reference sample and those of the corresponding sample with nanofiller blends were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Two peaks were observed in the melting and crystallization temperatures. This shows that the EVA/LDPE is an immiscible polymer blend. The thermal stability of the blends was improved by the presence of HNTs and ATH-sil nanoparticles. Thermal degradation temperatures were shifted to higher values by the presence of hybrid nanofillers. Finally, the flammability of the compositions was assessed. Flammability as reflected by the limiting oxygen index (OI) was increased by the presence of HNT and ATH-sil nanofiller and a hybrid system of the nanoparticles.

scholarly journals Synergistic Effect of Halloysite Nanotubes and Glycerol on the Physical Properties of Fish Gelatin Films

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1258 ◽  
Author(s):  
Xiaohu Qiang ◽  
Songyi Zhou ◽  
Zhuo Zhang ◽  
Qiling Quan ◽  
Dajian Huang
Keyword(s):  
Water Resistance ◽  
Water Solubility ◽  
Composite Films ◽  
Halloysite Nanotubes ◽  
Light Transmittance ◽  
Fish Gelatin ◽  
Moisture Uptake ◽  
Casting Method ◽  
Gelatin Films ◽  
Light Region

Fish gelatin (FG)/glycerol (GE)/halloysite (HT) composite films were prepared by casting method. The morphology of the composite films was observed by scanning electron microscopy (SEM). The effects of HT and GE addition on the mechanical properties, water resistance and optical properties of the composites were investigated. Results showed that with increasing GE content, the elongation at composite breaks increased significantly, but their tensile strength (TS) and water resistance decreased. SEM results showed that GE can partly promote HT dispersion in composites. TS and water resistance also increased with the addition of HTs. Well-dispersed HTs in the FG matrix decreased the moisture uptake and water solubility of the composites. All films showed a transparency higher than 80% across the visible light region (400–800 nm), thereby indicating that light transmittance of the resulting nanocomposites was slightly affected by GE and HTs.

Effect of Cellulose Nanocrystal on Crystallization Behavior of Poly(3–hydroxybutyrate–co–3–hydroxyvalerate)

2012 ◽  
Vol 430-432 ◽  
pp. 20-23 ◽  
Author(s):  
Hou Yong Yu ◽  
Zong Yi Qin
Keyword(s):  
Heterogeneous Nucleation ◽  
Crystallization Temperature ◽  
Crystallization Behavior ◽  
Crystallization Rate ◽  
Kinetics Study ◽  
Solvent Casting ◽  
Melt Crystallization ◽  
Casting Method ◽  
Isothermal Crystallization Kinetics ◽  
Biodegradable Nanocomposites

The biodegradable nanocomposites of poly (3–hydroxybutyrate–co–3–hydroxyvalerate) (PHBV) with different cellulose nanocrystals (CNCs) contents were prepared by a solvent casting method. The effects of CNCs on the crystallization behavior of PHBV were studied by DSC. The DSC results showed that compared to PHBV, the melt crystallization temperature increased to 92.3 °C for the nanocomposites with 10 wt. % CNCs, which indicated that the crystallization of PHBV became easier with the addition of CNCs. Moreover, the non–isothermal crystallization kinetics study illustrated that overall crystallization rate of PHBV in the nanocomposites was faster than that of neat PHBV, which should be attributed to the strong heterogeneous nucleation of CNCs.

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