scholarly journals THE INFLUENCE OF REACTION TIME ON THE PROPERTIES OF MICROWAVE SYNTHESIZED POLY(LACTIDE)

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Ivan Ristić ◽  
Milovan Jotanović ◽  
Tamara Erceg ◽  
Ljubiša Nikolić ◽  
Suzana Cakić ◽  
...  
Keyword(s):  
Reaction Time ◽  
Renewable Resources ◽  
Gel Permeation Chromatography ◽  
Polymer Materials ◽  
Scanning Calorimetry ◽  
Complete Life Cycle ◽  
Ft Ir ◽  
Synthesis Routes ◽  
Plant Feedstock

The consequence of drastic reduction in fossil fuel reserves has forced the scientific community to find and develop new ways to exploit renewable resources and optimize the process of polymer materials production. The aim is to obtain applicable polymer whose complete life cycle is set in ecological framework. Poly(lactide) (PLA) meets these requirements as biodegradable polyester whose monomer is derived from the plant feedstock containing carbohydrates. PLA could be prepared using the different synthesis routes, but from the point of energy saving, as well as environmental protection, the microwave synthesis of PLA is the best solution. In this work, poly(L-lactide) were synthesized in microwave reactor. Reaction time was varied, while the other parameters of the synthesis were constant. The structures of obtained polymers were confirmed by Fourier – transform infrared spectroscopy (FT-IR). For determination of molar masses of poly(L-lactide) samples, the gel permeation chromatography (GPC) was applied. Thermal properties were investigated by differential scanning calorimetry (DSC).

scholarly journals A Green Synthesis of Polylimonene Using Maghnite-H+, an Exchanged Montmorillonite Clay, as Eco-Catalyst

2019 ◽  
Vol 14 (1) ◽  
pp. 69 ◽  
Author(s):  
Hodhaifa Derdar ◽  
Mohammed Belbachir ◽  
Amine Harrane
Keyword(s):  
Reaction Time ◽  
Green Synthesis ◽  
Exchange Process ◽  
Gel Permeation Chromatography ◽  
Bulk Polymerization ◽  
Montmorillonite Clay ◽  
Scanning Calorimetry ◽  
Reaction Conditions ◽  
Ft Ir ◽  
Optimal Reaction

A new green polymerization technique to synthesis polylimonene (PLM) is carried out in this work. This technique consists of using Maghnite-H+ as eco-catalyst to replace Friedel-Crafts catalysts which are toxics. Maghnite-H+ is a montmorillonite silicate sheet clay which is prepared through a simple exchange process. Polymerization experiments are performed in bulk and in solution using CH2Cl2 as solvent. Effect of reaction time, temperature and amount of catalyst is studied, in order to find the optimal reaction conditions. The polymerization in solution leads to the best yield (48.5%) at -5°C for a reaction time of 6 h but the bulk polymerization, that is performed at 25°C, remains preferred even if the yield is lower (40.3%) in order to respect the principles of a green chemistry which recommend syntheses under mild conditions, without solvents and at room temperature. The structure of the obtained polymer (PLM) is confirmed by FT-IR and Nuclear Magnetic Resonance of proton (1H-NMR). The glass transition temperature (Tg) of the polylimonene is defined using Differential Scanning Calorimetry (DSC) and is between 113°C and 116°C. The molecular weight of the obtained polymer is determined by Gel Permeation Chromatography (GPC) analysis and is about 1360 g/mol. Copyright © 2019 BCREC Group. All rights reservedReceived: 26th May 2018; Revised: 11st September 2018; Accepted: 22nd September 2018; Available online: 25th January 2019; Published regularly: April 2019How to Cite: Derdar, H., Belbachir, M., Harrane, A. (2019). A Green Synthesis of Polylimonene Using Maghnite-H+, an Exchanged Montmorillonite Clay, as Eco-Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 14 (1): 69-78 (doi:10.9767/bcrec.14.1.2692.69-78)Permalink/DOI: https://doi.org/10.9767/bcrec.14.1.2692.69-78 

Synthesis, characterization and corrosion protection properties of polyN-(p-bromophenyl)-2-methacrylamide-co-glycidyl methacrylate on low nickel stainless steel

2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Sakvai Mohammed Safiullah ◽  
Deivasigamani Thirumoolan ◽  
Kottur Anver Basha ◽  
K. Mani Govindaraju ◽  
Dhanraj Gopi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Protection ◽  
Glycidyl Methacrylate ◽  
Electrochemical Impedance ◽  
Thermo Gravimetric Analysis ◽  
Gel Permeation Chromatography ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Protection Efficiency ◽  
Ft Ir

Abstract The synthesis of copolymers from different feed ratios of N-(p-bromophenyl)-2- methacrylamide (PBPMA) and glycidyl methacrylate (GMA) was achieved by using free radical solution polymerization technique and characterized using FT-IR, 1H and 13C NMR spectroscopy. The thermal stability of the synthesized copolymers was studied using thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The molecular weight of the copolymer is determined by gel permeation chromatography (GPC). The corrosion performances of low nickel stainless steel specimens dip coated with different composition of copolymers were investigated in 0.5 M H2SO4 using potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) techniques. The polarization and impedance measurements showed different corrosion protection efficiency with change in composition of the copolymers. It was found that the corrosion protection properties are owing to the barrier effect of the polymer layer covered on the low nickel stainless steel surfaces. However, it is observed that the mole ratio of PBPMA and GMA plays a major role in the protective nature of the copolymer.

Cationic copolymerization of 1,3-pentadiene with α-pinene

2014 ◽  
Vol 34 (7) ◽  
pp. 583-589 ◽  
Author(s):  
Ai-Yuan Li ◽  
Xiang-Dong Sun ◽  
Hui-Bo Zhang ◽  
Yong-Chun Zhang ◽  
Bin Wang ◽  
...  
Keyword(s):  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Polymerization Temperature ◽  
Scanning Calorimetry ◽  
Gardner Color ◽  
H Nmr ◽  
Cationic Copolymerization ◽  
Ft Ir ◽  
Better Than ◽  
C Nmr

Abstract The cationic copolymerization of 1,3-pentadiene (PD) with α-pinene (AP) initiated by aluminum trichloride (AlCl3) was carried out in N-pentane solvent. The effects of the polymerization temperature and the comonomer composition on the yield of the copolymer, softening point, Gardner color scale and number-average molecular weight (Mn) are discussed. The performance of the copolymer was better than that of AP homopolymer (PAP) and PD homopolymer (PPD). The structure of the copolymer was characterized by Fourier transform infrared spectroscopy (FT-IR), 1H-nuclear magnetic resonance (1H-NMR), 13C-NMR, differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). In addition, the reactivity ratios for AP (M1) and PD (M2) determined by the Kelen-Tudos method from low-conversion data are r1=0.58 and r2=5.92, respectively.

scholarly journals First, Do Not Degrade - an Alternative View on Polymer Laser Sintering

2021 ◽  
Author(s):  
Arkadiusz Antończak ◽  
Mateusz Wieczorek ◽  
Paulina Dzienny ◽  
Bartłomiej Kryszak ◽  
Anna Krokos ◽  
...  
Keyword(s):  
Gel Permeation Chromatography ◽  
Laser Sintering ◽  
Polymer Materials ◽  
Alternative View ◽  
Scanning Calorimetry ◽  
Entire Volume ◽  
Beam Laser ◽  
Dual Beam ◽  
Wide Range ◽  
First Time

<p>In the work, for the first time, the method of Dual Beam Laser Sintering of polymers (DBLS) was presented, in which, instead of heating the entire volume of the polymer throughout the entire process, a second, additional laser was used for selective in terms of volume and time heating of the material. The principle of operation and the design of the prototype are presented. Using the developed station, an experiment was carried out for sintering samples from technical polylactide powder as a function of selected process parameters. It confirmed the functionality of the method and proved that the sintering process can be controlled in a fairly wide range for the proposed method. A preliminary comparison of changes in the physicochemical properties of the obtained samples in relation to the samples sintered by standard laser sintering was carried out using Gel Permeation Chromatography, Fourier Transform Infrared Reflectance and Differential Scanning Calorimetry. The experiment showed that the presented method has the potential to limit the thermal degradation of sensitive polymer materials.</p>

scholarly journals Glycerolysis of Poly(lactic acid) as a Way to Extend the “Life Cycle” of This Material

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1963 ◽  
Author(s):  
Marcin Borowicz ◽  
Joanna Paciorek-Sadowska ◽  
Marek Isbrandt ◽  
Łukasz Grzybowski ◽  
Bogusław Czupryński
Keyword(s):  
Lactic Acid ◽  
Life Cycle ◽  
Raw Materials ◽  
Gel Permeation Chromatography ◽  
Acid Value ◽  
Economic Losses ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Economic Point

The article concerns the use of glycerolysis reaction as an alternative method of processing post-production and post-consumer waste from poly(lactic acid) (PLA). Management of waste is a very important issue from an environmental protection and economic point of view. Extending the “life cycle” of PLA is extremely important because it allows to make the most of this material. It also limits economic losses resulting from its disposal in the biodegradation process at the same time. This paper presents a method of glycerolysis of poly(lactic acid) waste using various amounts of anhydrous glycerol (mass ratio from 0.3 to 0.5 parts by weight of glycerol per 1.0 part by weight of PLA). This process was also carried out for pure, unmodified PLA Ingeo® (from NatureWorks) to compare the obtained results. The six liquid oligomeric polyhydric alcohols were obtained as a result of the synthesis. Then, they were subjected to physicochemical tests such as determination of color, smell, density, viscosity, and pH. In addition, the obtained raw materials were subjected to analytical tests such as determination of the hydroxyl value, acid value, water content, and elemental composition. The average molecular weights and dispersity were also tested by gel permeation chromatography (GPC). The assumed chemical structure of the obtained compounds was confirmed by spectroscopic methods such as FTIR, 1H NMR, 13C NMR. Glycerolysis products were also subjected to differential scanning calorimetry (DSC) to determine thermal parameters. The obtained research results have allowed the precise characterization of newly obtained products and determination of their suitability, e.g., for the synthesis of polyurethane (PUR) materials.

scholarly journals A New Strategy for the Synthesis of Hydroxyl Terminated Polystyrene-b-Polybutadiene-b-Polystyrene Triblock Copolymer with High Cis-1, 4 Content

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 598 ◽  
Author(s):  
Xin Min ◽  
Xiaodong Fan
Keyword(s):  
Triblock Copolymer ◽  
Gel Permeation Chromatography ◽  
Hydroxyl Group ◽  
The Novel ◽  
Scanning Calorimetry ◽  
Gel Permeation ◽  
New Strategy ◽  
Ft Ir ◽  
Novel Catalyst ◽  
Lower Glass Transition Temperature

This work reports the preparation of a hydroxyl terminated polystyrene-b-polybutadiene-b-polystyrene triblock copolymer (SBS) with high cis-1, 4 content via a novel nickel catalyst, [η3-Ni(CH2CHCHCH2OOCH3)][BPhF4]. FT-IR, 1H-NMR, and 13C NMR indicated that the polybutadiene segment of the copolymer contains greater than 90% cis-1, 4 structure, indicating achievement of the objective. Toward the functionalization goal, a hydroxyl group was successfully introduced at the end of the triblock copolymer (HO–SBS–OH). The results of gel permeation chromatography (GPC) revealed that the polymer is indeed a triblock copolymer, with no traces of homopolymer. Differential scanning calorimetry (DSC) showed that HO–SBS–OH synthesized using the novel catalyst had a lower glass transition temperature (Tg) than HO–SBS–OH synthesized with an alkyl lithium catalyst. Therefore, the polymer synthesized via the novel catalyst contains high cis-1,4 content and displays excellent low-temperature mechanical properties.

Preparation and characterization of tung oil-rosin-based polyester internal sizing agent

2021 ◽  
Vol 36 (3) ◽  
pp. 503-511
Author(s):  
Yazhou Xu ◽  
Songlin Dai ◽  
Liangwu Bi ◽  
Yuxiang Chen
Keyword(s):  
Maleic Anhydride ◽  
Dynamic Contact Angle ◽  
Gel Permeation Chromatography ◽  
Dynamic Contact ◽  
Scanning Calorimetry ◽  
Measuring Device ◽  
Tung Oil ◽  
Angle Measuring ◽  
Ft Ir ◽  
Sizing Agents

Abstract A series of tung oil-rosin-based polyester (TRP) used as internal sizing agents were prepared using rosin, tung oil, maleic anhydride, and glycerol. TRP structure and properties were examined using Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). The TRP latexes were subsequently used as internal sizing agents, and the sizing properties were evaluated using a scanning electron microscope (SEM), a video-based dynamic contact angle measuring device and a Cobb absorbency tester. The optimal conditions for preparing the TRP sizing agent were as follows: the hydroxy-carboxyl ratio of the material was 0.25; the maleic anhydride dosage was 20 % of rosin; and the tung oil dosage was 40 % of rosin. Under the best conditions, the sized paper Cobb-60 was 15.6  g / m 2 \text{g}/{\text{m}^{2}} , the tensile index was 45.1 N·m/g, the burst index was 3.1 kPa· m 2 {\text{m}^{2}} /g, and the tear index was 15.6 mN· m 2 {\text{m}^{2}} /g.

scholarly journals DSC, FT-IR, NIR, NIR-PCA and NIR-ANOVA for determination of chemical stability of diuretic drugs: impact of excipients

2018 ◽  
Vol 16 (1) ◽  
pp. 116-132 ◽  
Author(s):  
Anna Gumieniczek ◽  
Hanna Trębacz ◽  
Łukasz Komsta ◽  
Agnieszka Atras ◽  
Beata Jopa ◽  
...  
Keyword(s):  
High Temperature ◽  
Citric Acid ◽  
Principal Component ◽  
Magnesium Stearate ◽  
Scanning Calorimetry ◽  
Diuretic Drugs ◽  
Temperature And Humidity ◽  
Ft Ir ◽  
Selection Of

AbstractIt is well known that drugs can directly react with excipients. In addition, excipients can be a source of impurities that either directly react with drugs or catalyze their degradation. Thus, binary mixtures of three diuretics, torasemide, furosemide and amiloride with different excipients,i.e. citric acid anhydrous, povidone K25 (PVP), magnesium stearate (Mg stearate), lactose, D-mannitol, glycine, calcium hydrogen phosphate anhydrous (CaHPO4) and starch, were examined to detect interactions. High temperature and humidity or UV/VIS irradiation were applied as stressing conditions. Differential scanning calorimetry (DSC), FT-IR and NIR were used to adequately collect information. In addition, chemometric assessments of NIR signals with principal component analysis (PCA) and ANOVA were applied.Between the excipients examined, lactose and starch did not show any interactions while citric acid, PVP, Mg stearate and glycine were peculiarly operative. Some of these interactions were shown without any stress, while others were caused or accelerated by high temperature and humidity, and less by UV/VIS light. Based on these results, potential mechanisms for the observed interactions were proposed Finally, we conclude that selection of appropriate excipients for torasemide, furosemide and amiloride is an important question to minimize their degradation processes, especially when new types of formulations are being manufactured.

scholarly journals Synthesis of a new organic probe 4-(4 acetamidophenylazo) pyrogallol for spectrophotometric determination of Bi(III) and Al(III) in pharmaceutical samples

2021 ◽  
Vol 40 (1) ◽  
pp. 108-126
Author(s):  
Jumana W. Ammar ◽  
Zainab A. Khan ◽  
Marwa N. Ghazi ◽  
Naser A. Naser
Keyword(s):  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Scanning Calorimetry ◽  
Spectrophotometric Methods ◽  
Modern Development ◽  
Relative Standard ◽  
Visible Spectra ◽  
Ft Ir ◽  
Linear Solvation Energy

Abstract A modern development discusses the synthesis and validity of simple, sensitive, and versatile spectrophotometric methods for Bi(III) and Al(III) determination in pharmaceutical formulations have been conducted. In the present paper, 4-(4 acetamidophenylazo) pyrogallol has been synthesized as a new organic compound, 4-APAP, by coupling pyrogallol in a regulated pH medium with diazotized p-aminoacetanilide. 4-APAP was identified by methods of FT-IR, 1H-NMR, 13C-NMR, and thermal analysis (thermogravimetry and differential scanning calorimetry). Solvatochromic activity was also studied in solvents with different polarities. The Kamlet and Taft linear solvation energy relationship was used to correlate shifts in UV-Visible spectra of 4-APAP with Kamlet-Taft parameters (α, β, and π*). The optimum assay conditions showed linearity from 0.3–13 to 0.5–11 μg·mL−1 for Bi(III) and Al(III), respectively. Molar absorptivity values were 3.365 × 104 and 0.356 × 104 L·mol−1·cm−1 for Bi(III) and Al(III), with similar Sandell's sensitivity measures of 0.006 and 0.008 μg·cm−2. Detection limits and quantification limits were 0.013 and 0.043 μg·mL−1 for Bi(III), respectively, and 0.018 and 0.059 μg·mL−1 for Al(III) with the relative standard deviation for determination of both metal ions using 4-APAP probe being <2.0%. The validity, accuracy, and efficiency of the approaches were demonstrated by the determination of Bi(III) and Al(III) in different formulations.

Synthesis and Characterization of Novel Polymer of Vinyl Carbazole Bearing Thiophene Groups

2012 ◽  
Vol 562-564 ◽  
pp. 512-515
Author(s):  
Yun Xian Yang ◽  
Ji Ping Yang ◽  
Bing Zhou ◽  
Jing Yu Zhang
Keyword(s):  
Conjugated Polymer ◽  
Suzuki Reaction ◽  
Gel Permeation Chromatography ◽  
High Glass Transition Temperature ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Infrared Spectrometer ◽  
Ft Ir ◽  
Fluorescence Spectrometer

Combination of vinyl carbazole and thiophene groups’ excellent thermal properties and optical properties, a novel polymer named poly(2,7-bi-2-thienyl-9-vinyl-9-H-carbazole) was synthesized via radical polymerization and Suzuki reaction. The polymer was characterized using Fourier transform infrared spectrometer(FT-IR), gel permeation chromatography(GPC), differential scanning calorimetry(DSC), and X-Ray fluorescence spectrometer(XRF). It was found that this π-conjugated polymer containing vinyl carbazole and thiophene groups gave a high glass transition temperature (Tg=251°C). This feature made poly(2,7-bi-2-thienyl-9-vinyl-9-H-carbazole) possessing an excellent thermal performance.

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