Poly(vinyl alcohol) and poly(sodium styrene sulfonate) compatibility by differential scanning calorimetry, Fourier transform infrared and scanning electron microscopy

2009 ◽  
Vol 114 (4) ◽  
pp. 2261-2269 ◽  
Author(s):  
Chamekh Mbareck ◽  
Trong Quang Nguyen ◽  
Jean Marc Saiter
1994 ◽  
Vol 370 ◽  
Author(s):  
Un-Jen Chu ◽  
Jae-Ho Kim ◽  
Cheol Park ◽  
Richard E. Robertson

AbstractThe presence of poly(vinyl alcohol) (PVA) in portland cement during its hydration was found to induce changes in the microstructure and behavior of the paste that forms around aggregate. The microstructure was studied with scanning electron microscopy in secondary electron, backscattered electron, and EDX mapping modes and with Fourier-transform infraredspectroscopy. The adhesion between cement paste and aggregate was examined with planar aggregate surfaces. With concentrations of the order of 1% by weight of PVA based onthe weight of the cement, the deposition of calcium hydroxide on the aggregate surface was found to be diminished and the porous layer that usually surrounds the aggregate to be reduced in thickness. Also, the bond between the aggregate and cement paste was increasedenough for the bond to approach the strength of the cement.


2020 ◽  
Vol 7 (1) ◽  
pp. 23
Author(s):  
Muthia Fadhila ◽  
Salman Umar ◽  
Erizal Zaini

Pada penetitian ini pembentukan kokristal asam usnat-N-methyl-D-glucamine bertujuan untuk meningkatkan kelarutan dan laju disolusi asam usnat serta uji efektivitasnya dalam kadar IL-8 pada tikus inflamasi. Kokristal asam usnat–N-methyl-D-glucamine dibuat dengan perbandingan 1:1 ekuimola dengan metode penguapan pelarut menggunakan etanol. Karakterisasi sampel dilakukan dengan difraksi sinar-X, Differential Scanning Calorimetry (DSC), Fourier Transform Infrared (FTIR), dan Scanning Electron Microscopy (SEM). Evaluasi kokristal yang dilakukan mencakup uji kelarutan, uji laju disolusi, dan penentuan kadar interleukin-8 (IL-8) pada tikus inflamasi. Uji kelarutan dilakukan menggunakan pelarut air suling bebas CO2 sedangkan uji laju disolusi menggunakan media air suling bebas CO2 0.25% (b/v) sodium lauril sulfat (SLS), kedua larutan uji dianalisis menggunakan spektrofotometer UV-Vis. Pemeriksaan IL-8 tikus inflamasi menggunakan metode ELISA. Hasil karakterisasi difraksi sinar-X menunjukkan profil difraktogram yang berbeda dari komponen penyusun yang mengindikasikan terbentuknya fase kokristal. Hasil termogram DSC menunjukkan adanya puncak endotermik baru yang berbeda dengan kedua komponen penyusun. Spektrum FT-IR menunjukkan terjadinya pergeseran bilangan gelombang pada spektrum kokristal dibandingkan spektrum asam usnat dan N-methyl-D-glucamine. Analisis SEM menunjukkan perubahan morfologi partikel. Kelarutan dan laju disolusi kokristal meningkat secara signifikan (P<0,05) sebanyak 24 kali dan 23 kali dibandingkan dengan senyawa asam usnat murni. Kokristal dapat menurunkan kadar IL-8 pada tikus inflamasi yang setara dengan aktivitas antiinflamasi asetosal (P<0,05). Disimpulkan bahwa koristal asam usnat - N-methyl-D-glucamine dapat meningkatkan kelarutan, laju disolusi, dan menurunkan kadar IL-8 tikus inflamasi.


2012 ◽  
Vol 627 ◽  
pp. 651-654
Author(s):  
Xin Min Hao ◽  
Wen Juan Ma ◽  
Ge Gan ◽  
Peng Cheng Zhao ◽  
Yuan Yang ◽  
...  

This paper introduces the study of structure on EVA (ethylene-vinyl acetate)/hemp stem powder compound system. The micro behavior of EVA/hemp system was measured by SEM (Scanning Electron Microscopy), and its thermal properties were measured by DSC (Differential Scanning Calorimetry ). It indicates that hemp stem core has entered into EVA foaming system successfully when measured by FT-IR (Fourier Transform Infrared).


Author(s):  
Samir A Atara ◽  
Moinuddin M Soniwala

Objective: Calcium pectinate is an insoluble hydrophilic material used for sustained release delivery. The objective of the study was formulation and evaluation pectin-calcium chloride beads of azathioprine.Methods: Calibration curves of azathioprine were prepared in 0.1N HCl solution (pH-1.2) and phosphate buffer (pH-6.8 and pH-7.4). Fourier transform infrared spectroscopy and differential scanning calorimetry was used to determine compatibility between azathioprine and excipients. Formulation and optimization of calcium-pectinate beads were performed. The coating of the optimized batch was performed with eudragit S100. Micrometric properties, scanning electron microscopy, in vitro azathioprine release, and stability study was performed. Dissolution kinetic study was assessed for various kinetics models of the optimized batch. The Wilcoxon test followed by the Dunnett’s multiple comparison tests were performed between uncoated and coated beads in vitro dissolution profile of optimized batch in 0.1N HCl after 2 h.Results: Fourier transform infrared spectroscopy and differential scanning calorimetry had identical peaks with that of pure azathioprine in compatibility study. Scanning electron microscopy of an uncoated optimized batch of beads indicated the smooth and uniform surface of prepared beads. Eudragit S100 coating was decreased release of azathioprine release in 0.1N HCl after 2 h (p = 0.049, q = 3.533). Korsmeyer/Peppa's model was applied with release exponent higher than 1. In vitro percentage cumulative azathioprine release was identical before and after stability study.Conclusion: Calcium pectinate beads of azathioprine, a multi-particulate dosage form using pH-dependent approaches were prepared.


2021 ◽  
pp. 095400832110055
Author(s):  
Yang Wang ◽  
Yuhui Zhang ◽  
Yuhan Xu ◽  
Xiucai Liu ◽  
Weihong Guo

The super-tough bio-based nylon was prepared by melt extrusion. In order to improve the compatibility between bio-based nylon and elastomer, the elastomer POE was grafted with maleic anhydride. Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA) were used to study the compatibility and micro-distribution between super-tough bio-based nylon and toughened elastomers. The results of mechanical strength experiments show that the 20% content of POE-g-MAH has the best toughening effect. After toughening, the toughness of the super-tough nylon was significantly improved. The notched impact strength was 88 kJ/m2 increasing by 1700%, which was in line with the industrial super-tough nylon. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) were used to study the crystallization behavior of bio-based PA56, and the effect of bio-based PA56 with high crystallinity on mechanical properties was analyzed from the microstructure.


e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Andrea Pucci ◽  
Letizia Moretto ◽  
Giacomo Ruggeri ◽  
Francesco Ciardelli

AbstractA new polyethylene-compatible terthiophene chromophore, 5”-thio-(3- butyl)nonyl-2,2’:5’,2”-terthiophene, with melting point lower than 0°C was prepared and used for linear polarizers based on ultra-high-molecular-weight polyethylene (UHMWPE). Differential scanning calorimetry and scanning electron microscopy indicate that the new chromophore is dispersed uniformly in films of UHMWPE obtained by casting from solution. The films show excellent dichroic properties (dichroic ratio 30) at rather low drawing ratio (≈ 20) . Moreover, qualitative agreement is observed with the Ward pseudo-affine deformation scheme.


2019 ◽  
Vol 953 ◽  
pp. 209-214
Author(s):  
Yi Teng Zhang ◽  
Lian Zuo ◽  
Jin Chao Yang ◽  
Wei Xia Zhao ◽  
Xiang Xiong Zeng

The main objective of this study is to investigate the effect of cementitious capillary crystalline waterproofing (CCCW) material on the water impermeability and microstructure of concrete. The water impermeability of concrete covered with or without CCCW material was tested according to the Chinese standard GB 18445-2012. The results indicate that concretes coated with CCCW material showed much higher water impermeability than blank ones, and the ratio of water impermeability pressure between them reached 275. The samples obtained in various depths of hardened cement paste specimens with or without CCCW coating were analyzed through scanning electron microscopy (SEM) and thermogravimetry-differential scanning calorimetry (TG-DSC), to study the differences in microstructure and hydration products. The results present that after a 28-day standard curing, there were lots of ettringite crystals and CaCO3 formed in the paste in 1 cm from the coating, but the action depth of the CCCW coating could not reach 3 cm. The ettringite and CaCO3 is precipitated in the pore structure of cement matrix and filling the voids, which leads to the significant enhancement in water impermeability.


2019 ◽  
Vol 107 (8) ◽  
pp. 725-735
Author(s):  
Hoda H. Saleh ◽  
Rehab Sokary ◽  
Zakaria I. Ali

Abstract Polyaniline (PANI) nanoparticles and PANI/poly vinyl alcohol (PVA) nanocomposite films were synthesized by the oxidative polymerization of aniline and ammonium peroxodisulfate (APS), as an oxidizing agent in aqueous medium. The PANI/PVA nanocomposite films were exposed to γ-irradiation after oxidative polymerization. Synthesized polyaniline (PANI) nanoparticles and PANI/PVA nanocomposite films were characterized by attenuated total reflectance infrared spectroscopy (FTIR-ATR), X-ray diffraction, high resolution scanning electron microscopy, (HRSEM) high resolution transmission electron microscopy, (HRTEM) and UV-VIS absorption spectroscopy. Energy band gap of PANI nanofibers was determined from Tauc’s plots which equal 4.2 eV. Scanning electron microscopy images show that chemically synthesized of polyaniline has nanofibers structure and irradiated PANI/PVA nanocomposite have a mixture of nanorod and nanosphere structures. The transmission electron microscopy show that chemically synthesized of polyaniline has average length in the range 34 ± 10 nm with less wide distribution, where as the irradiated PANI/PVA nanocomposite has coreshell structure.


2017 ◽  
Vol 67 (5) ◽  
pp. 510 ◽  
Author(s):  
Han Gao ◽  
Wei Jiang ◽  
Jie Liu ◽  
Gazi Hao ◽  
Lei Xiao ◽  
...  

<p>An energetic co-crystal consisting of the most promising military explosive 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) and the most well-known oxidant applied in propellants ammonium perchlorate has been prepared with a simple solvent evaporation method. Scanning electron microscopy revealed that the morphology of co-crystal differs greatly from each component. The X-ray diffraction spectrum, FTIR, Raman spectra, and differential scanning calorimetry characterisation further prove the formation of the co-crystal. The result of determination of hygroscopic rate indicated the hygroscopicity was effectively reduced. At last, the crystallisation mechanism has been discussed.</p>


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