Preparation and characterization of oxidized starch-graft-poly(styrene-butyl acrylate) latex via emulsion polymerization

2014 ◽  
Vol 34 (7) ◽  
pp. 611-616 ◽  
Author(s):  
Shijie Cheng ◽  
Jun Xu ◽  
Yumin Wu
Keyword(s):  
Emulsion Polymerization ◽  
Butyl Acrylate ◽  
Colloidal Stability ◽  
Graft Copolymerization ◽  
Scanning Calorimetry ◽  
Oxidized Starch ◽  
Ir Transmission ◽  
Ft Ir ◽  
Synthetic Latex

Abstract Oxidized starch-graft-poly(styrene-butyl acrylate) [OS-g-P(St-BA)] latex was synthesized by the graft copolymerization of OS with St and n-butyl acrylate (BA) via emulsion polymerization. The graft copolymers were characterized by Fourier transform infrared (FT-IR), transmission electronic microscopy (TEM), dynamic light scattering, thermogravimetry (TG), and differential scanning calorimetry (DSC). The effects of the amount of OS, monomers, and initiator on graft copolymerization were investigated. Under the optimal conditions, the percentage of graft (PG), grafting efficiency (GE), and ζ potential could reach 256.5%, 41.7%, and -30.1 mV, respectively. The results indicated that the OS grafted onto particles greatly enhanced the colloidal stability of latex. The thermal stability properties of OS-g-P(St-BA) were also improved by the addition of OS. The OS-g-P(St-BA) latex may be used to partly replace the conventional synthetic latex for paper coating.

Synthesis and Characterization of Reactive Graft Copolymers of Poly(butyl Acrylate) and Cellulose

2005 ◽  
Vol 13 (5) ◽  
pp. 467-478
Author(s):  
Ghanshyam S. Chauhan ◽  
Baljit Singh ◽  
Suresh Kumar ◽  
Anupama Chinkara
Keyword(s):  
Butyl Acrylate ◽  
Metal Ion ◽  
Graft Copolymerization ◽  
Graft Copolymers ◽  
Optimum Conditions ◽  
Ion Sorption ◽  
Graft Yield ◽  
Ft Ir ◽  
Structural Aspects

Butyl acrylate was graft copolymerized onto cellulose extracted from pine needles by a simultaneous gamma radiation initiation method. Optimum conditions for the maximum graft yield were established. Polymerization and grafting parameters such as %grafting (Pg), % grafting efficiency (%GE), rates of polymerization (Rp), homopolymerization (Rh) and graft copolymerization (Rg) were also determined. Grafted cellulose was further functionalized to produce poly(acryloyl hydroxylamine) [Cell-g-poly(CONHOH)] so as to generate active (-CONHOH) groups on the cellulose backbone. Graft copolymers were characterized by elemental analysis, by FT-IR and by a swelling study. An attempt was also made to study the sorption of Fe+2 and Cu+2 as model metal ions onto the candidate copolymers, in order to investigate their selectivity in metal ion sorption and to determine the effect on metal ion sorption of the structural aspects of the hydrogels and other functionalized graft copolymers, so as to identify their end-uses.

Thermal Behaviour of Candesartan Active substance and in pharmaceutical compounds

2017 ◽  
Vol 68 (8) ◽  
pp. 1895-1902
Author(s):  
Ioana Cristina Tita ◽  
Eleonora Marian ◽  
Bogdan Tita ◽  
Claudia Crina Toma ◽  
Laura Vicas
Keyword(s):  
Thermal Behaviour ◽  
Active Substance ◽  
Pharmaceutical Research ◽  
Pharmaceutical Product ◽  
Nitrogen Atmosphere ◽  
Pure Substance ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir

Thermal analysis is one of the most frequently used instrumental techniques in the pharmaceutical research, for the thermal characterization of different materials from solids to semi-solids, which are of pharmaceutical relevance. In this paper, simultaneous thermogravimetry/derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC) were used for characterization of the thermal behaviour of candesartan cilexetil � active substance (C-AS) under dynamic nitrogen atmosphere and nonisothermal conditions, in comparison with pharmaceutical product containing the corresponding active substance. It was observed that the commercial samples showed a different thermal profile than the standard sample, caused by the presence of excipients in the pharmaceutical product and to possible interaction of these with the active substance. The Fourier transformed infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRPD) were used as complementary techniques adequately implement and assist in interpretation of the thermal results. The main conclusion of this comparative study was that the TG/DTG and DSC curves, together with the FT-IR spectra, respectively X-ray difractograms constitute believe data for the discrimination between the pure substance and pharmaceutical forms.

scholarly journals THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES

2021 ◽  
Vol 23 (1) ◽  
pp. 16
Author(s):  
Vienna Saraswaty ◽  
Rossy Choerun Nissa ◽  
Bonita Firdiana ◽  
Akbar Hanif Dawam Abdullah
Keyword(s):  
Tensile Strength ◽  
Physicochemical Characterization ◽  
Face Mask ◽  
Physicochemical Characteristics ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
Ft Ir ◽  
The Government ◽  
Plastic Pellets

THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES. The government policy to wear a face mask during the COVID-19 pandemic has increased disposable face mask wastes. Thus, to reduce such wastes, it is necessary to evaluate the physicochemical characteristics of disposable face masks wastes before the recycling process and the recycled products. In this study, physicochemical characterization of the 3-ply disposable face masks and the recycled plastic pellets after disinfection using 0.5% v/v sodium hypochlorite were evaluated. A set of parameters including the characterization of surface morphology by a scanning electron microscope (SEM), functional groups properties by a fourier transform infra-red spectroscopy (FT-IR), thermal behavior by a differential scanning calorimetry (DSC), tensile strength and elongation at break were evaluated. The surface morphological of each layer 3-ply disposable face mask showed that the layers were composed of non-woven fibers. The FT-IR evaluation revealed that 3-ply disposable face mask was made from a polypropylene. At the same time, the DSC analysis found that the polypropylene was in the form of homopolymer. The SEM analysis showed that the recycled plastic pellets showed a rough and uneven surface. The FT-IR, tensile strength and elongation at break of the recycled plastic pellets showed similarity with a virgin PP type CP442XP and a recycled PP from secondary recycling PP (COPLAST COMPANY). In summary, recycling 3-ply disposable face mask wastes to become plastic pellets is recommended for handling disposable face mask wastes problem.

scholarly journals Formulation and Characterization of Aceclofenac-Loaded Nanofiber Based Orally Dissolving Webs

Pharmaceutics ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 417 ◽  
Author(s):  
Emese Sipos ◽  
Nóra Kósa ◽  
Adrienn Kazsoki ◽  
Zoltán-István Szabó ◽  
Romána Zelkó
Keyword(s):  
Oral Absorption ◽  
Vinyl Pyrrolidone ◽  
Drug Dissolution ◽  
In Vitro Dissolution ◽  
Drug Release Profile ◽  
Scanning Calorimetry ◽  
Ft Ir ◽  
Fast Dissolution ◽  
Poly Vinyl Pyrrolidone

Aceclofenac-loaded poly(vinyl-pyrrolidone)-based nanofiber formulations were prepared by electrospinning to obtain drug-loaded orally disintegrating webs to enhance the solubility and dissolution rate of the poorly soluble anti-inflammatory active that belongs to the BCS Class-II. Triethanolamine-containing ternary composite of aceclofenac-poly(vinyl-pyrrolidone) nanofibers were formulated to exert the synergistic effect on the drug-dissolution improvement. The composition and the electrospinning parameters were changed to select the fibrous sample of optimum fiber characteristics. To determine the morphology of the nanofibers, scanning electron microscopy was used. Fourier transform infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC) were applied for the solid-state characterization of the samples, while the drug release profile was followed by the in vitro dissolution test. The nanofibrous formulations had diameters in the range of few hundred nanometers. FT-IR spectra and DSC thermograms indicated the amorphization of aceclofenac, which resulted in a rapid release of the active substance. The characteristics of the selected ternary fiber composition (10 mg/g aceclofenac, 1% w/w triethanolamine, 15% w/w PVPK90) were found to be suitable for obtaining orally dissolving webs of fast dissolution and potential oral absorption.

Preparation and Characterization of PMAA/SiO2 Composite Particle Via Emulsion Polymerization

2012 ◽  
Vol 528 ◽  
pp. 184-187 ◽  
Author(s):  
Ke Hong Zhang ◽  
Jun Juan Du ◽  
Hui Xiao ◽  
Yan Yuan
Keyword(s):  
Acrylic Acid ◽  
Emulsion Polymerization ◽  
Silica Gel ◽  
Graft Polymerization ◽  
Polymer Layer ◽  
Grafted Polymer ◽  
Chemically Modified ◽  
Ft Ir ◽  
Silica Gel Particles

Silica gel particle was chemically modified by using 3-methacryloxypropyl trimethoxysilane (KH-570) as coupling agent. Then poly methyl acrylic acid (PMAA) was grafted on the surface of particles MPS-SiO2 with the method of Emulsion Polymerization, and grafting particles PMMA/SiO2 were prepared. The grafting particle PMAA/SiO2 was characterized by using FT-IR, TG and SEM. The experimental results show that the graft polymerization of methyl acrylic acid (MAA) on onto the surface of silica gel particles can successfully realized using the method of “graft from”. During the graft polymerization, the grafted polymer layer is a hindrance to the subsequent graft polymerization. When the grafted polymer layer reach to a certain density via overlapping and entwisting, a kinetic barrier will be built up. Hence, the grafting degree of the polymer under a certain condition has a limiting value.

scholarly journals Structural stability of biofilms produced from silkworm cocoon fibers

2021 ◽  
pp. 54-54
Author(s):  
Souza Felício ◽  
Henrique Santana
Keyword(s):  
Conformational Changes ◽  
Casting Process ◽  
Scanning Calorimetry ◽  
Molecular Conformations ◽  
Freeze Dried ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Silkworm Cocoon ◽  
Band Characteristic

Biofilms were obtained from cocoons of the silkworm, Bombyx mori, involving the removal of sericin, extraction and solubilization of fibroin fibers, dialysis of fibroin dispersions and preparation of biofilms by the casting process. Biofilm transparency was verified by UV-Vis spectroscopy and thermal stability by thermogravimetric/differential scanning calorimetry (TG/DSC). Soon after preparation, the solidification of the fibroin solution prepared from the cocoons and extracted by the Ajisawa method was monitored until the biofilm stabilized, using Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy (ATR FT-IR) as a function of time. The results showed that there is a change in the conformation from the silk I structure (?-helix) to silk II (?-sheet). In order to improve the characterization of the biofilms obtained by the Ajisawa method and LiBr solubilization of fibroin fibers, Raman spectroscopy was used to verify stabilization of the different possible molecular conformations for the fibers in these materials, by comparison with the cocoon spectra and those of the solid (freeze-dried hydrogel) precipitated by dialysis for 72 h. By comparing the Raman spectra of the biofilms in terms of the intensities of the broadened band characteristic of amide I, it was possible to assess the conformational changes in both materials based on possible transitions between ?-sheet conformations and flexible ?-helix and ?-turn structures. The results showed a dispersion of these conformations in the biofilms generated and in the solid freeze-dried hydrogel spectrum, and the ?-sheet conformation was found to be predominant. The TG and DSC curves showed that the materials with higher ?-sheet content exhibited higher thermal resistance. Thus, the data obtained further elucidate the properties of these materials which are widely used in various processes.

scholarly journals Characterization of the Spindle Morphology Nanomicelles Assembled from Sericin and Gelatin

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Xiaozhou Su ◽  
Lei Li ◽  
Weihan Huang
Keyword(s):  
Electron Microscopy ◽  
Protein Concentration ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Ft Ir ◽  
And Storage ◽  
Ft Ir Spectroscopy

Complex nanomicelles were prepared by sericin and type A gelatin with molecular weight of 5789 Da and 128664 Da separately. The assembling conditions were as follows: mass ratio (sericin/gelatin) was 1 : 1, protein concentration was 0.5%, temperature was 35°C, and assembling time was 18 hours. Scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), and dynamic light scattering (DLS) were conducted to observe and characterize the complex nanomicelles. Results showed that the complex sericin/gelatin micelles was a kind of nanospindle micelles. The micelles had high electrochemical stability, thermal stability, antidilution stability, and storage stability.

Synthesis and characterization of novel tetrakis (3-hydroxypropylmercapto)-substituted phthalocyanines

2013 ◽  
Vol 17 (06n07) ◽  
pp. 573-586 ◽  
Author(s):  
Çiğdem Yağcı ◽  
Ahmet Bilgin
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Synthesis And Characterization ◽  
The Novel ◽  
Scanning Calorimetry ◽  
Metal Free ◽  
Visible Spectra ◽  
Ft Ir ◽  
Aromatic Nitro

A phthalonitrile precursor 4-(3-hydroxypropylmercapto)phthalonitrile (3) was synthesized via a base-catalyzed nucleophilic aromatic nitro displacement of 4-nitrophthalonitrile with the 3-mercapto-1-propanol. A novel tetrasubstituted metal-free phthalocyanine (4) ( M = 2 H ) and its metal complexes (5–8) ( M = Zn , Ni , Cu and Co ) bearing 3-hydroxypropylmercapto moieties were prepared by the cyclotetramerization reaction of (3) with the appropriate materials. The visible spectra of the zinc(II) phthalocyanine (5) was recorded with different concentrations and different ions as Ag +, Hg 2+ and Pb 2+ in DMF and also with different solvents as dimethylformamide and pyridine. Fluorescence spectrum of the compound (5) was also studied. Temperature and frequency dependence of AC conductivity for (4–8) was investigated in air and under vacuum and were found to be ~10-8–10-5 S.m-1. Thermal properties of the phthalocyanines were examined by differential scanning calorimetry. All the novel compounds have been characterized by elemental analysis, UV-vis, FT-IR, NMR and MS spectral data and DSC techniques.

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