Poly(3-hydroxybutyrate) - Organo Modified Montmorillonite Nanohybrid; Preparation and Characterization

2012 ◽  
Vol 622-623 ◽  
pp. 263-270 ◽  
Author(s):  
Ali Salehabadi ◽  
Mohamad Abu Bakar

Nano-biohybrid, based on biodegradable polyester, poly (3-hydroxybutyrate) (PHB), and a commercial organo modified montmorillonite (MMT), were prepared by solvent casting technique. Morphology and non-isothermal degradation of PHB and PHB/MMT hybrids were characterized by POM and TG-DTG technique. In the composite materials, an increase MMT loading in the PHB decreased the onset temperature (Tonset) of thermal degradation, while it achieved higher values upon increasing the heating rate. Kissinger plots deduced a trend of the degradation activation energy, Ed, which was related to the agglomeration of MMT. The thermal degradation rate constant, k, was related to the MMT loading in PHB. X-ray diffraction analysis confirmed the expansion of MMT silicate layers.

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 274
Author(s):  
Azlin Fazlina Osman ◽  
Lilian Siah ◽  
Awad A. Alrashdi ◽  
Anwar Ul-Hamid ◽  
Ismail Ibrahim

In this work, dolomite filler was introduced into thermoplastic starch (TPS) matrix to form TPS-dolomite (TPS-DOL) biocomposites. TPS-DOL biocomposites were prepared at different dolomite loadings (1 wt%, 2 wt%, 3 wt%, 4 wt% and 5 wt%) and by using two different forms of dolomite (pristine (DOL(P) and sonicated dolomite (DOL(U)) via the solvent casting technique. The effects of dolomite loading and sonication process on the mechanical properties of the TPS-DOL biocomposites were analyzed using tensile and tear tests. The chemistry aspect of the TPS-DOL biocomposites was analyzed using Fourier transform infrared spectroscopy (FTIR) and X-Ray Diffraction (XRD) analysis. According to the mechanical data, biocomposites with a high loading of dolomite (4 and 5 wt%) possess greater tensile and tear properties as compared to the biocomposites with a low loading of dolomite (1 and 2 wt%). Furthermore, it is also proved that the TPS-DOL(U) biocomposites have better mechanical properties when compared to the TPS-DOL(P) biocomposites. Reduction in the dolomite particle size upon the sonication process assisted in its dispersion and distribution throughout the TPS matrix. Thus, this led to the improvement of the tensile and tear properties of the biocomposite. Based on the findings, it is proven that the sonication process is a simple yet beneficial technique in the production of the TPS-dolomite biocomposites with improved tensile and tear properties for use as packaging film.


Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 494 ◽  
Author(s):  
S. El-Bashir ◽  
M. AlSalhi ◽  
F. Al-Faifi ◽  
W. Alenazi

Luminescent polymethylmethacrylate (PMMA) films were prepared by the solvent-casting technique from polymer solution doped with different concentrations of red perylene dyestuffs (KREMER 94720 and KREMER 94739). The effect of the dye concentration on the structure and spectroscopic properties was studied using X-ray diffraction (XRD), transmission electron microscope (TEM) optical absorption, and fluorescence spectroscopy. The optimum dye concentration of photoselective PMMA films was determined by the fluorescence spectroscopy measurements and showed the best emission properties for the doping concentration 10−3 wt % of the investigated dyes. The accelerated photostability tests showed promising stability of the prepared films towards terrestrial solar ultraviolet radiation (UVA). The results endorsed a promising application of the investigated films in photoselective greenhouse cladding applications as the optimized film fluoresces at the action spectra of special chlorophyll a.


2005 ◽  
Vol 480-481 ◽  
pp. 333-338 ◽  
Author(s):  
B. Herrero ◽  
M. Arroyo ◽  
Miguel A. López-Manchado

Thermoplastic vulcanizates nanocomposites based on polypropylene (PP) and ethylene–propylene-diene terpolymer rubber (EPDM) blends reinforced with organoclay modified montmorillonite have been prepared via melt intercalation. The silicate layers of the clay were intercalated and dispersed at a nanometer level in the matrix blends. The nanocomposites exhibit improved mechanical properties, this effect being more evident at high EPDM contents in the blend (above 80%). This behavior is attributed to the fact that the EPDM chains are more easily inserted into the galleries silicate, giving rise to a more intercalated structure as was observed by X-ray diffraction.


Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 558
Author(s):  
Wenhui Zhu ◽  
Caiyun Zhang ◽  
Yali Chen ◽  
Qiliang Deng

Photothermal materials are attracting more and more attention. In this research, we synthesized a ferrocene-containing polymer with magnetism and photothermal properties. The resulting polymer was characterized by Fourier-transform infrared (FT-IR), vibrating sample magnetometer (VSM), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Its photo-thermocatalytic activity was investigated by choosing methylene blue (MB) as a model compound. The degradation percent of MB under an irradiated 808 nm laser reaches 99.5% within 15 min, and the degradation rate is 0.5517 min−1, which is 145 times more than that of room temperature degradation. Under irradiation with simulated sunlight, the degradation rate is 0.0092 min−1, which is approximately 2.5 times more than that of room temperature degradation. The present study may open up a feasible route to degrade organic pollutants.


2014 ◽  
Vol 513-517 ◽  
pp. 33-36 ◽  
Author(s):  
Zi Chang Xie ◽  
Ying Wang ◽  
Peng Wang ◽  
Lei Zhang

In this paper, W-doped TiO2 (W-TiO2) powder was prepared in hydrothermal method by mixing TiO2 and ammonium metatungstate. The catalysts were characterized by X-ray diffraction and ultraviolet spectrophotometer. The results displayed that W-TiO2 showed an anatase crystallite structure with 2 % W content. W-element in W-TiO2 was amorphous state. The guaiacol was degraded with the W-TiO2 in the visible light. It was a model compounds of lignin existed in the plant fibers. The degradation rate of guaiacol was increased with the photocatalytic time, as high as 88.21 % after 360 min irradiation. It was concluded that the W-TiO2 had an obvious photocatalytic activity under visible light. It can be used in the photocatalytic degradation of lignin.


2012 ◽  
Vol 214 ◽  
pp. 31-34
Author(s):  
Fu Quan Guo ◽  
Ying Ying Li ◽  
Bin Guo ◽  
Hao Liang

Optical–grade polycarbonate (PC) was separated from optical disks by a chemical approach and used to prepare nanocomposite to make full use of the wasted polymers. A quaternary ammonium-modified montmorillonite (organic montmorillonite, OMMT) was chosen as a modifier and an auxiliary functional resin (CBT160) was utilized to exfoliate the layers of montmorillonite. The characterization results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) for PC/ OMMT (5wt %) revealed that an exfoliation structure of the nanocomposite was obtained. The mechanical measurements show a great increase in tensile strength and Izod impact strength of PC/ OMMT nanocomposite compared with the recycled optical–grade PC.


Author(s):  
Shan-Ting Hsu ◽  
Y. Lawrence Yao

Poly(L-lactic acid) (PLLA) has been shown to have potential medical usage such as in drug delivery because it can degrade into bioabsorbable products in physiological environments, and its degradation is affected by crystallinity. In this paper, the effect of film formation method and annealing on the crystallinity of PLLA are investigated. The films are made through solvent casting and spin coating methods, and subsequent annealing is conducted. The resulting crystalline morphology, structure, conformation, and intermolecular interaction are examined using optical microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. It is observed that solvent casting produces category 1 spherulites while annealed spin coated films leads to spherulites of category 2. Distinct lamellar structures and intermolecular interactions in the two kinds of films have been shown. The results enable better understanding of the crystallinity in PLLA, which is essential for its drug delivery application.


Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1238
Author(s):  
Murendeni P. Ravele ◽  
Opeyemi A. Oyewo ◽  
Sam Ramaila ◽  
Lydia Mavuru ◽  
Damian C. Onwudiwe

In this paper, spherical-shaped pure phase djurleite (Cu31S16) and roxbyite (Cu7S4) nanoparticles were prepared by a solvothermal decomposition of copper(II) dithiocarbamate complex in dodecanthiol (DDT). The reaction temperature was used to control the phases of the samples, which were represented as Cu31S16 (120 °C), Cu31S16 (150 °C), Cu7S4 (220 °C), and Cu7S4 (250 °C) and were characterized by using X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), and absorption spectroscopy. The samples were used as photocatalysts for the degradation of tetracycline (TC) under visible light irradiation. The results of the study showed that Cu7S4 (250 °C) exhibited the best activity in the reaction system with the TC degradation rate of up to 99% within 120 min of light exposure, while the Cu31S16 (120 °C) system was only 46.5% at the same reaction condition. In general, roxbyite Cu7S4 (250 °C) could be considered as a potential catalyst for the degradation of TC in solution.


2013 ◽  
Vol 747 ◽  
pp. 682-685
Author(s):  
Raphaël Cretois ◽  
Nadège Follain ◽  
Jérémie Soulestin ◽  
Eric Dargent ◽  
Laurent Lebrun ◽  
...  

Nanocomposites based on bacterial semi-crystalline polyhydroxyalkanoates, poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) or poly (3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)), and organo-modified montmorillonite nanoclay are prepared by melt processing. All nanocomposites are characterized by X-Ray Diffraction (XRD) and Transmission Electronic Microscopy (TEM) and exhibit a mainly intercalated structure. Concerning water transport properties, a decrease of barrier properties for PHBV/nanoclay films is measured due to the affinity of nanoclay to water; whereas for P(3HB-co-4HB)/nanoclay nanocomposites, a decrease of the water permeability is observed relative to the tortuosity effect. Eventually, as a function of nanoclay content, a competition is evidenced between the tortuosity effect and the water sorption induced by nanoclay.


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