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.

A New Green Process for Synthesising High Quality PLLA Materials

2013 ◽  
Vol 750-752 ◽  
pp. 1377-1380 ◽  
Author(s):  
Hui Li Shao ◽  
Xian Jue Zhou ◽  
Xue Chao Hu
Keyword(s):  
Molecular Weight ◽  
Ring Opening ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Ring Opening Polymerization ◽  
Green Process ◽  
Weight Average Molecular Weight ◽  
H Nmr ◽  
Ft Ir ◽  
C Nmr

Synthesis of Poly(L-lactide) (PLLA) by the ring-opening polymerization (ROP) of L-lactides in supercritical carbon dioxide (SC-CO2) with co-solvent were studied. Effects of kinds of co-solvent on the molecular weight (MW) and the molecular weight distribution (MWD) of the resultant polymers were investigated by the gel permeation chromatography (GPC). The resultant polymers were also characterized with1H NMR,13C NMR and FT-IR. It was found that PLLA with high purity and almost without racemization could be obtained by this technology and the acetone is the best co-solvent for this kind of polymerization. By using stannous octoate as initiator and acetone as co-solvent, PLLA having a weight-average molecular weight (Mw) near to 9×104and polydispersity index (PDI) of 1.7 was successfully synthesized.

Characterization of bi-layered magnetic nanoparticles synthesized via two-step surface-initiated ring-opening polymerization

2015 ◽  
Vol 87 (11-12) ◽  
pp. 1085-1097 ◽  
Author(s):  
Li Wang ◽  
Stefan Baudis ◽  
Karl Kratz ◽  
Andreas Lendlein
Keyword(s):  
Magnetic Nanoparticles ◽  
Ring Opening ◽  
Average Molecular Weight ◽  
Polymer Networks ◽  
Gel Permeation Chromatography ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Transmission Electron

AbstractA versatile strategy to integrate multiple functions in a polymer based material is the formation of polymer networks with defined nanostructures. Here, we present synthesis and comprehensive characterization of covalently surface functionalized magnetic nanoparticles (MNPs) comprising a bi-layer oligomeric shell, using Sn(Oct)2 as catalyst for a two-step functionalization. These hydroxy-terminated precursors for degradable magneto- and thermo-sensitive polymer networks were prepared via two subsequent surface-initiated ring-opening polymerizations (ROPs) with ω-pentadecalactone and ε-caprolactone. A two-step mass loss obtained in thermogravimetric analysis and two distinct melting transitions around 50 and 85°C observed in differential scanning calorimetry experiments, which are attributed to the melting of OPDL and OCL crystallites, confirmed a successful preparation of the modified MNPs. The oligomeric coating of the nanoparticles could be visualized by transmission electron microscopy. The investigation of degrafted oligomeric coatings by gel permeation chromatography and 1H-NMR spectroscopy showed an increase in number average molecular weight as well as the presence of signals related to both of oligo(ω-pentadecalactone) (OPDL) and oligo(ε-caprolactone) (OCL) after the second ROP. A more detailed analysis of the NMR results revealed that only a few ω-pentadecalactone repeating units are present in the degrafted oligomeric bi-layers, whereby a considerable degree of transesterification could be observed when OPDL was polymerized in the 2nd ROP step. These findings are supported by a low degree of crystallinity for OPDL in the degrafted oligomeric bi-layers obtained in wide angle X-ray scattering experiments. Based on these findings it can be concluded that Sn(Oct)2 was suitable as catalyst for the preparation of nanosized bi-layered coated MNP precursors by a two-step ROP.

Structure and properties of poly(lactic acid)/poly(lactic acid)-α-cyclodextrin inclusion compound composites

2017 ◽  
Vol 37 (9) ◽  
pp. 897-909
Author(s):  
Li Zhang ◽  
Weijun Zhen ◽  
Yufang Zhou
Keyword(s):  
Lactic Acid ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Mechanical Analysis ◽  
Poly Lactic Acid ◽  
Polymerization Temperature ◽  
Scanning Calorimetry ◽  
Synthesis Conditions ◽  
Cyclodextrin Inclusion ◽  
Comprehensive Performance

Abstract Poly(lactic acid) (PLA) was synthesized using a green catalyst, nano-zinc oxide (ZnO). The optimum synthesis conditions of PLA were as follows: a stoichiometric amount of 0.5 wt% of nano-ZnO, polymerization time of 14 h, and polymerization temperature of 170°C. Gel permeation chromatography results showed that the weight-average molecular weight (Mw) of PLA was 13,072 g/mol with a polydispersity index (PDI) of 1.7. Furthermore, PLA-α-cyclodextrin inclusion compounds (PLA-CD-ICs) were prepared by ultrasonic co-precipitation techniques. X-ray diffraction analysis and Fourier transform infrared spectroscopy demonstrated the change in lattice of α-CD from a cage configuration to a tunnel structure and the existence of some physical interactions between α-CD and PLA in the PLA-CD-ICs. To enhance the crystallization properties of PLA, PLA/PLA-CD-IC composites were blended with different contents of PLA-CD-ICs as nucleating agents. The crystallization behavior and comprehensive performance were investigated by differential scanning calorimetry, polarized optical microscopy, tensile testing, dynamic mechanical analysis, and scanning electron microscopy. Compared to PLA, the crystallinities of PLA/PLA-CD-IC composites were increased by 24.0%, 26.3%, 27.3%, and 31.8%. The results of all the analyses proved that PLA-CD-ICs were useful as green organic nucleators and improved the comprehensive performance of PLA materials.

scholarly journals Green anionic polymerization of vinyl acetate using Maghnite-Na+ (Algerian MMT): synthesis characterization and reactional mechanism

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Badia Imene Cherifi ◽  
Mohammed Belbachir ◽  
Abdelkader Rahmouni
Keyword(s):  
Vinyl Acetate ◽  
Polymerization Reaction ◽  
Resonance Spectroscopy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Simple Filtration ◽  
Renewable Material ◽  
Ft Ir ◽  
C Nmr

AbstractIn this work, the green polymerization of vinyl acetate is carried out by a new method which consists in the use of clay called Maghnite-Na+ as an ecological catalyst, non-toxic, inexpensive and recyclable by simple filtration. X-ray diffraction (XRD) showed that Maghnite-Na+ is successfully obtained after cationic treatment (sodium) on raw Maghnite. It is an effective alternative to replace toxic catalysts such as benzoyl peroxide (BPO) and Azobisisobutyronitrile (AIBN) which are mostly used during the synthesis of polyvinyl acetate (PVAc) making the polymerization reaction less problematic for the environment. The synthesis reaction is less energetic by the use of recycled polyurethane as container for the reaction mixture and which is considered as a renewable material and a good thermal insulator which maintains the temperature at 0 °C for 6 h. The reaction in bulk is also preferred to avoid the use of a solvent and therefore to stay in the context of green chemistry. In these conditions, the structure of obtained polymer is established by Nuclear Magnetic Resonance Spectroscopy 1H NMR and 13C NMR. Infrared spectroscopy (FT-IR) is also used to confirm the structure of PVAc. Thermogravimetric analysis (TGA) showed that it is thermally stable and it starts to degrade from 330 °C while Differential Scanning calorimetry (DSC) shows that this polymer has a glass transition temperature (Tg  = 50 °C). The composition in PVAc/Maghnite-Na+ (7 wt% of catalyst) is the most tensile resistant with a force of 182 N and a maximum stress of 73.16 MPa, the most flexible (E  = 955 MPa) and the most ductile (εr  = 768%).

Silicon alkyne hybrid polymers containing Si–H and Si–CH3

2017 ◽  
Vol 30 (3) ◽  
pp. 259-266 ◽  
Author(s):  
Shuaishuai Liu ◽  
Quan Zhou ◽  
Zhengqiang Peng ◽  
Ning Song ◽  
Lizhong Ni
Keyword(s):  
Oxidative Stability ◽  
Oxidation Resistance ◽  
Gel Permeation Chromatography ◽  
High Heat ◽  
Structure Design ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Thermal And Oxidative Stability ◽  
Gel Permeation ◽  
C Nmr

A silicon-containing polymer (HMSA), synthesized with n-BuLi, trichloroethylene, dichloromethylsilane, and dimethyldichlorosilane, with three different proportions of Si–H, and its influence on thermal oxidation have been studied. The structures of HMSA were characterized by Fourier transform infrared spectra, 1H-Nuclear Magnetic Resonance (H-NMR), 13C-NMR, 29Si-NMR, and gel permeation chromatography. Thermal and oxidative stabilities were studied by differential scanning calorimetry and thermogravimetric analysis, and the cross-linking reaction mechanisms of the HMSA were discussed. All the polymers exhibited excellent thermal and oxidation resistance; particularly, HMSA-1 showed high heat-resistant and thermo-oxidative stability; the temperatures of 5% weight loss ( Td5) were 636.3 and 645.5°C, and the residues at 1000°C were 87.07 and 86.23% in nitrogen and air, respectively. This system had excellent thermal and oxidative stability, and through the structure design, control of heat oxidation resistance was realized.

Synthesis and characterization of 4-chloromethylstyrene polymers containing bulky organosilicon groups

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Kazem Dindar Safa ◽  
Mirzaagha Babazadeh
Keyword(s):  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Gel Permeation Chromatography ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Gel Permeation ◽  
Covalently Linked ◽  
C Nmr

Abstract The homopolymer of 4-chloromethylstyrene and its copolymers with styrene (in 1:3 and 1:1 mole ratio) were synthesized by bulk and solution freeradical polymerisations, respectively, at 70±1°C using α,α'-azoisobutyronitrile as an initiator. Highly sterically hindered tris(trimethylsilyl)methyl (Tsi) substituents were then covalently linked to the obtained homopolymer and copolymers. The polymers were characterized by IR, 1H NMR and 13C NMR, differential scanning calorimetry (DSC) and gel permeation chromatography. DSC showed that incorporation of Tsi substituents in the side chains of homopolymer and copolymers increases the rigidity of the polymers and, subsequently, their glass transition temperature.

Ultrasound-assisted aqua-mediated synthesis of multi-substituted tetrahydropyridine-3-carboxylates using N-carboxymethyl-3-pyridinium hydrogensulfate ([N-CH2CO2H-3-pic]+HSO4−) as a new efficient ionic liquid catalyst

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Kobra Nikoofar ◽  
Fatemeh Shahriyari
Keyword(s):  
Ionic Liquid ◽  
Reaction Times ◽  
Aromatic Aldehydes ◽  
Environmentally Benign ◽  
H Nmr ◽  
Sonic Waves ◽  
Ft Ir ◽  
High Yields ◽  
Work Up ◽  
C Nmr

AbstractA simple, straightforward, and ultrasound-promoted method for the preparation of some highly functionalized tetrahydropyridines reported via pseudo five-component reaction of (hetero)aromatic aldehydes, different anilines, and alkyl acetoacetates in the presence of [N-CH2CO2H-3-pic]+HSO4−, as a novel ionic liquid, in green aqueous medium. The IL was synthesized utilizing simple and easily-handled substrates and characterized by FT-IR, 1H NMR, 13C NMR, GC-MASS, FESEM, EDX, and TGA/DTG techniques. The procedure contains some highlighted aspects which are: (a) performing the MCR in the presence of aqua and sonic waves, as two main important and environmentally benign indexes in green and economic chemistry, (b) high yields of products within short reaction times, (c) convenient work-up procedure, (d) preparing the new IL via simple substrates and procedure.

Liquid crystalline polyureas with oligo(ethylene glycol) sequences

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Shahram Mehdipour-Ataei ◽  
Leila Akbarian-Feizi
Keyword(s):  
Liquid Crystalline ◽  
Spectroscopic Method ◽  
Polymerization Reaction ◽  
X Ray Diffraction ◽  
Subsequent Reaction ◽  
Scanning Calorimetry ◽  
Polar Solvents ◽  
X Ray ◽  
H Nmr ◽  
Ft Ir

AbstractA diamine monomer containing ester, amide and ether functional groups was prepared and its polymerization reaction with different diisocyanates to give main chain poly(ester amide ether urea)s was investigated. The monomer was synthesized via reaction of terephthaloyl chloride with 4-hydroxybenzoic acid and subsequent reaction of the resulted diacid with 1,8-diamino-3,6-dioxaoctane. The polymers were characterized by FT-IR and 1H-NMR spectroscopic method and elemental analysis. The resulting polymers exhibited excellent solubility in polar solvents. Crystallinity of the resulted polymers was evaluated by wide-angle X-ray diffraction (WXRD) method, and they exhibited semi-crystalline patterns. The glass transition temperatures (Tg) of the polymers determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) were in the range of 88-112 °C. The temperatures for 10% weight loss (T10) from their thermogravimetric analysis (TGA) curves were found to be in the range of 297-312 °C in air. Also the prepared polyureas showed liquid crystalline character.

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.

scholarly journals SYNTHESIS AND STRUCTURAL ELUCIDATION OF AMINO ACETYLENIC AND THIOCARBAMATES DERIVATIVES FOR 2-MERCAPTOBENZOTHIAZOLE AS ANTIMICROBIAL AGENTS

2017 ◽  
Vol 9 (2) ◽  
pp. 192
Author(s):  
Aseel Alsarahni ◽  
Zuhair Muhi Eldeen ◽  
Elham Al-kaissi ◽  
Ibrahim Al- Adham ◽  
Najah Al-muhtaseb
Keyword(s):  
Antimicrobial Activity ◽  
Elemental Analysis ◽  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Benzothiazole Derivatives ◽  
H Nmr ◽  
Ft Ir ◽  
Potential Antimicrobial Activity ◽  
C Nmr

<p><strong>Objective: </strong>To design and synthesize amino acetylenic and thiocarbonate of 2-mercapto-1,3-benthiazoles as potential antimicrobial agents.</p><p><strong>Methods: </strong>A new series of 2-{[4-(t-amino-1-yl) but-2-yn-1-yl] sulfanyl}-1,3-benzothiazole derivatives (AZ1-AZ6), and S-1,3-benzothiazol-2-yl-O-alkyl carbonothioate derivatives were synthesised, with the aim that the target compounds show new and potential antimicrobial activity. The elemental analysis was indicated by the EuroEA elemental analyzer, and biological characterization was via IR, <sup>1</sup>H-NMR, [13]C-NMR, DSC were determined with the aid of Bruker FT-IR and Varian 300 MHz spectrometer using DMSO-d<sub>6</sub> as a solvent.<em> </em><em>In vitro </em>antimicrobial activity, evaluation was done for the synthesised compounds, by agar diffusion method and broth dilution test. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined. <em></em></p><p><strong>Results: </strong>The IR, <sup>1</sup>H-NMR, <sup>13</sup>C-NMR, DSC and elemental analysis were consistent with the assigned structures. Compound of 2-{[4-(4-methylpiperazin-1-yl)but-2-yn-1-yl] sulfanyl}-1,3-benzothiazole (AZ1), 2-{[4-(2-methylpiperidin-1-yl)but-2-yn-1-yl]sulfanyl}-1,3-benzothiazole (AZ2), 2-{[4-(piperidin-1-yl) but-2-yn-1-yl]sulfanyl}-1, 3-benzothiazole (AZ6), S-1,3-benzothiazol-2-yl-O-ethyl carbonothioate (AZ7), and S-1,3-benzothiazol-2-yl-O-(2-methylpropyl) carbonothioate (AZ9) showed the highest antimicrobial activity against <em>Pseudomonas aeruginosa </em>(<em>P. aeruginosa</em>), AZ-9 demonstrated the highest antifungal activity against <em>Candida albicans </em>(<em>C. albicans</em>), with MIC of 31.25 µg/ml.</p><p><strong>Conclusion: </strong>These promising results promoted our interest to investigate other structural analogues for their antimicrobial activity further.</p>

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