Investigation of artificial ageing of PVC stabilized with epoxidized sunflower oil as biobased derivative

2021 ◽  
Vol 04 ◽  
Author(s):  
Nadia Gallouze ◽  
Naima Belhaneche-Bensemrab ◽  
Sophie Commereuc ◽  
Vincent Verney

Objective: The objective of this work is the study of artificial ageing of semi-rigid and plasticized polyvinyl chloride (PVC) stabilized with epoxidized sunflower oil (ESO) as biobased derivative in combination with zinc and calcium stearates. Materials and Methods: For comparison, a formulation of PVC plasticized and stabilized with epoxidized soya bean oil (ESBO) was considered. Artificial ageing was carried out during the 304 hours. Samples were taken off after: 48, 146, 234 and 304 hours and then characterized. The evolution of density, glass transition temperature and morphology, was followed as a function of the time. The structural modifications of polymer were analyzed by Fourier transform infrared spectroscopy in attenuated total reflectance and transmission modes. Results: The results showed a little decrease of density, a considerable increase of the glass transition temperatures values and a change of morphology. All changes in the properties of PVC relate to formation of new chemical structures. Conclusion: Globally, it was found that ESO exhibited similar performances to those of ESBO

Author(s):  
Firmansyah A. ◽  
Winingsih W. ◽  
Soebara Y S

Analysis of natural product remain challenging issues for analytical chemist, since natural products are complicated system of mixture. The most popular methods of choice used for quality control of raw material and finished product are high performance liquid chromatography (HPLC), gas chromatography (GC) and mass spectrometry (MS). The utilization of FTIR-ATR (Fourier Transform Infrared-Attenuated Total Reflectance) method in natural product analysis is still limited. This study attempts to expand the use of FTIR spectroscopy in authenticating Indonesian coffee powder.The coffee samples studied were taken from nine regions in Indonesia, namely Aceh Gayo, Flores, Kintamani, Mandheling, Papua, Sidikalang, Toraja, Kerinci and Lampung.The samples in the form of coffee bean from various regions were powdered . The next step conducted was to determine the spectrum using the FTIR-ATR (Attenuated Total Reflectance) using ZnSe crystal of 8000 resolution. Spectrum samples, then, were analyzed using chemometrics. The utilized chemometric model was the principal component analysis (PCA) and cluster analysis (CA). Based on the chemometric analysis, there are similarities between Aceh Gayo coffee with Toraja coffee, Mandailing coffee, Kintamani coffee and Flores coffee. Sidikalang coffee has a similarity to Flores coffee; Papua coffee has a similarity to Sidikalang coffee; Lampung coffee has a similarity to Sidikalang coffee, while Kerinci coffee has a similarity to Papua coffee.


2008 ◽  
Vol 59 (11) ◽  
Author(s):  
Cristina Dusescu ◽  
Anca Borcea ◽  
Vasile Matei ◽  
Ion Popa ◽  
Irina Gabriela Radulescu

The present paper studies biodiesel samples preparation by transesterification and compares their physical and chemical properties (biofuels prepared from different raw materials - vegetable oils: sunflower oil, crocus oil and soya bean oil) and the biodegradability degree, as well as the possibilities of the integration of such production unit in industrial diagram of auto fuels production.


Author(s):  
Nikunj D. Patel ◽  
Niranjan S. Kanaki

Background: Numerous Ayurvedic formulations contains tugaksheeree as key ingredient. Tugaksheereeis the starch gained from the rhizomes of two plants, Curcuma angustifoliaRoxb. (Zingiberaceae) and Marantaarundinacea (MA) Linn. (Marantaceae). Objective: The primary concerns in quality assessment of Tugaksheeree occur due to adulteration or substitution. Method: In current study, Fourier transform infrared (FTIR) technique with attenuated total reflectance (ATR) facility was used to evaluate tugaksheeree samples. Total 10 different samples were studied and transmittance mode was kept to record the spectra devoid of pellets of KBR. Further treatment was given with multi component tools by considering fingerprint region of the spectra. Multivariate analysis was performed by various chemometric methods. Result: Multi component methods like Principal Component Analysis (PCA), and Hierarchical Cluster Analysis (HCA)were used to discriminate the tugaksheeree samples using Minitab software. Conclusion: This method can be used as a tool to differentiate samples of tugaksheeree from its adulterants and substitutes.


2021 ◽  
Vol 2 (2) ◽  
pp. 419-430
Author(s):  
Ankur Bajpai ◽  
James R. Davidson ◽  
Colin Robert

The tensile fracture mechanics and thermo-mechanical properties of mixtures composed of two kinds of epoxy resins of different chemical structures and functional groups were studied. The base resin was a bi-functional epoxy resin based on diglycidyl ether of bisphenol-A (DGEBA) and the other resins were (a) distilled triglycidylether of meta-amino phenol (b) 1, 6–naphthalene di epoxy and (c) fluorene di epoxy. This research shows that a small number of multifunctional epoxy systems, both di- and tri-functional, can significantly increase tensile strength (14%) over neat DGEBA while having no negative impact on other mechanical properties including glass transition temperature and elastic modulus. In fact, when compared to unmodified DGEBA, the tri-functional epoxy shows a slight increase (5%) in glass transition temperature at 10 wt.% concentration. The enhanced crosslinking of DGEBA (90 wt.%)/distilled triglycidylether of meta-amino phenol (10 wt.%) blends may be the possible reason for the improved glass transition. Finally, the influence of strain rate, temperature and moisture were investigated for both the neat DGEBA and the best performing modified system. The neat DGEBA was steadily outperformed by its modified counterpart in every condition.


Author(s):  
Angelo Tricase ◽  
Angela Stefanachi ◽  
Rosaria Anna Anna Picca ◽  
Eleonora Macchia ◽  
Alessandro Favia ◽  
...  

A combined cyclic voltammetry (CV) and grazing angle – attenuated total reflectance (GA-ATR) IR study on the interchain interaction driven reorganization of self-assembled monolayers (SAMs) in an electric field, is...


2021 ◽  
pp. 002580242110109
Author(s):  
Sweety Sharma ◽  
Rito Chophi ◽  
Jaskirandeep Kaur Jossan ◽  
Rajinder Singh

The most important task in a criminal investigation is to detect and identify the recovered biological stains beyond reasonable scientific doubt and preserve the sample for further DNA analysis. In the light of this fact, many presumptive and confirmatory tests are routinely employed in the forensic laboratories to determine the type of body fluid. However, the currently used techniques are specific to one type of body fluid and hence it cannot be utilized to differentiate multiple body fluids. Moreover, these tests consume the samples in due process, and thus it becomes a great limitation especially considering the fact that samples are recovered in minute quantity in forensic cases. Therefore, such limitations necessitate the use of non-destructive techniques that can be applied simultaneously to all types of bodily fluids and allow sample preservation for further analysis. In the current work, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy has been used to circumvent the aforementioned limitations. The important factors which could influence the detection of blood such as the effect of substrates, washing/chemical treatment, ageing, and dilution limits on the analysis of blood have been analysed. In addition, blood discrimination from non-blood substance (biological and non-biological in nature) has also been studied. Chemometric technique that is PCA–LDA has been used to discriminate blood from other body fluids and it resulted in 100% accurate classification. Furthermore, blood and non-blood substances including fake blood have also been classified into separate clusters with a 100% accuracy, sensitivity, and specificity. All-inclusive, this preliminary study substantiates the potential application of ATR-FTIR spectroscopy for the non-destructive identification of blood traces in simulated forensic casework conditions with 0% rate of false classification.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4445
Author(s):  
Tiphaine Wong ◽  
Lorette Brault ◽  
Eric Gasparotto ◽  
Romuald Vallée ◽  
Pierre-Yves Morvan ◽  
...  

Marine polysaccharides are part of the huge seaweeds resources and present many applications for several industries. In order to widen their potential as additives or bioactive compounds, some structural modifications have been studied. Among them, simple hydrophobization reactions have been developed in order to yield to grafted polysaccharides bearing acyl-, aryl-, alkyl-, and alkenyl-groups or fatty acid chains. The resulting polymers are able to present modified physicochemical and/or biological properties of interest in the current pharmaceutical, cosmetics, or food fields. This review covers the chemical structures of the main marine polysaccharides, and then focuses on their structural modifications, and especially on hydrophobization reactions mainly esterification, acylation, alkylation, amidation, or even cross-linking reaction on native hydroxyl-, amine, or carboxylic acid functions. Finally, the question of the necessary requirement for more sustainable processes around these structural modulations of marine polysaccharides is addressed, considering the development of greener technologies applied to traditional polysaccharides.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 931
Author(s):  
Ioana-Codruţa Mirică ◽  
Gabriel Furtos ◽  
Ondine Lucaciu ◽  
Petru Pascuta ◽  
Mihaela Vlassa ◽  
...  

The aim of this research was to develop new electrospun membranes (EMs) based on polycaprolactone (PCL) with or without metronidazole (MET)/nano-hydroxyapatite (nHAP) content. New nHAP with a mean diameter of 34 nm in length was synthesized. X-ray diffraction (XRD) and attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR) were used for structural characterization of precursors and EMs. The highest mechanical properties (the force at maximum load, Young’s modulus and tensile strength) were found for the PCL membranes, and these properties decreased for the other samples in the following order: 95% PCL + 5% nHAP > 80% PCL + 20% MET > 75% PCL + 5% nHAP + 20% MET. The stiffness increased with the addition of 5 wt.% nHAP. The SEM images of EMs showed randomly oriented bead-free fibers that generated a porous structure with interconnected macropores. The fiber diameter showed values between 2 and 16 µm. The fiber diameter increased with the addition of nHAP filler and decreased when MET was added. New EMs with nHAP and MET could be promising materials for guided bone regeneration or tissue engineering.


Nano Research ◽  
2021 ◽  
Author(s):  
Xiushang Xu ◽  
Marco Di Giovannantonio ◽  
José I. Urgel ◽  
Carlo A. Pignedoli ◽  
Pascal Ruffieux ◽  
...  

AbstractGraphene nanoribbons (GNRs) have potential for applications in electronic devices. A key issue, thereby, is the fine-tuning of their electronic characteristics, which can be achieved through subtle structural modifications. These are not limited to the conventional armchair, zigzag, and cove edges, but also possible through incorporation of non-hexagonal rings. On-surface synthesis enables the fabrication and visualization of GNRs with atomically precise chemical structures, but strategies for the incorporation of non-hexagonal rings have been underexplored. Herein, we describe the on-surface synthesis of armchair-edged GNRs with incorporated five-membered rings through the C-H activation and cyclization of benzylic methyl groups. Ortho-Tolyl-substituted dibromobianthryl was employed as the precursor monomer, and visualization of the resulting structures after annealing at 300 °C on a gold surface by high-resolution noncontact atomic force microscopy clearly revealed the formation of methylene-bridged pentagons at the GNR edges. These persisted after annealing at 340 °C, along with a few fully conjugated pentagons having singly-hydrogenated apexes. The benzylic methyl groups could also migrate or cleave-off, resulting in defects lacking the five-membered rings. Moreover, unexpected and unique structural rearrangements, including the formation of embedded heptagons, were observed. Despite the coexistence of different reaction pathways that hamper selective synthesis of a uniform structure, our results provide novel insights into on-surface reactions en route to functional, non-benzenoid carbon nanomaterials.


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