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.

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 1-n-Butyl-3-methylimidazolium-2-carboxylate: a versatile precatalyst for the ring-opening polymerization of ε-caprolactone and rac-lactide under solvent-free conditions

2013 ◽  
Vol 9 ◽  
pp. 647-654 ◽  
Author(s):  
Astrid Hoppe ◽  
Faten Sadaka ◽  
Claire-Hélène Brachais ◽  
Gilles Boni ◽  
Jean-Pierre Couvercelle ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Ring Opening ◽  
Gel Permeation Chromatography ◽  
Ring Opening Polymerization ◽  
Solvent Free ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Solvent Free Conditions ◽  
Gel Permeation

The ring-opening polymerization of ε-caprolactone (ε-CL) and rac-lactide (rac-LA) under solvent-free conditions and using 1-n-butyl-3-methylimidazolium-2-carboxylate (BMIM-2-CO2) as precatalyst is described. Linear and star-branched polyesters were synthesized by successive use of benzyl alcohol, ethylene glycol, glycerol and pentaerythritol as initiator alcohols, and the products were fully characterized by 1H and 13C{1H} NMR spectroscopy, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). BMIM-2-CO2 acts as an N-heterocyclic carbene precursor, resulting from in situ decarboxylation, either by heating under vacuo (method A) or by addition of NaBPh4 (method B). Possible catalytic and deactivation mechanisms are proposed.

Novel Polymerization of Myrcene in Aqueous Media via Cyclodextrin-Complexes

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
SooWhan Choi ◽  
Helmut Ritter
Keyword(s):  
Room Temperature ◽  
Aqueous Media ◽  
Gel Permeation Chromatography ◽  
Solution Temperature ◽  
Cyclodextrin Complexes ◽  
Scanning Calorimetry ◽  
Critical Solution Temperature ◽  
Gel Permeation ◽  
Redox Initiator ◽  
C Nmr

AbstractFree radical homopolymerization with methylated β-cyclodextrin (CD) complexed myrcene (1a) and co-polymerization of 1a with diethyl fumarate (2a) and styrene (3a) were carried out using redox initiator in aqueous media at room temperature. Control experiments showed that uncomplexed myrcene (1) does not polymerize under similar conditions in water. The polymers obtained were characterized by means of 1H/13C-NMR spectroscopy, differential scanning calorimetry (DSC) and gel-permeation chromatography (GPC). Additionally, Nisopropylacrylamide containing copolymer was synthesized in water using redox initiator and the lower critical solution temperature (LCST) behaviour was studied.

Structural Studies of Native Paecilomyces sp. Exopolysaccharide

2007 ◽  
Vol 62 (9-10) ◽  
pp. 623-626
Author(s):  
Luis Lillo ◽  
Julio Alarcón ◽  
Gerardo Cabello ◽  
Sergio Águila
Keyword(s):  
Gel Permeation Chromatography ◽  
Structural Studies ◽  
H Nmr ◽  
Gel Permeation ◽  
C Nmr

A polysaccharide separated from Paecilomyces sp. was determined by gel permeation chromatography to be homogeneous. HPLC showed a monosaccharide containing d-glucose and d-fructose at a ratio of about 2:1. The results obtained from IR, 1H NMR, and 13C NMR analyses confirmed the proposed structure.

New Arylidene—Siloxane Polyesters

2003 ◽  
Vol 15 (3) ◽  
pp. 231-242 ◽  
Author(s):  
Carmen Racles ◽  
Vasile Cozan ◽  
Maria Cazacu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Nmr Spectroscopy ◽  
Liquid Crystalline ◽  
Gel Permeation Chromatography ◽  
Polymer Structure ◽  
Scanning Calorimetry ◽  
Polarized Optical Microscopy ◽  
H Nmr ◽  
Gel Permeation ◽  
Thermotropic Liquid Crystalline Behavior

New siloxane-containing polyesters with arylidene mesogenic moieties were prepared by copolycondensation reactions between bis(hydroxybuthyl)siloxanes, 2,6-bis(4-hydroxybenzylidene)cyclohexanone, and diacid chlorides such as sebacoyl and terephthaloyl. The polymer structure was confirmed by IR and 1H-NMR spectroscopy. They were characterized by gel permeation chromatography and ultraviolet analyses. The thermotropic liquid crystalline behavior was investigated by differential scanning calorimetry and polarized optical microscopy.

Thermal and Oxidation Behavior of Boron-Silicon-Containing Arylacetylene Polymer

2012 ◽  
Vol 560-561 ◽  
pp. 179-183
Author(s):  
Xin Xin Sun ◽  
Hui Min Qi ◽  
Kang Kang Guo ◽  
Fa Rong Huang ◽  
Lei Du
Keyword(s):  
Differential Scanning Calorimetry ◽  
Oxidative Stability ◽  
Grignard Reagent ◽  
Oxidation Behavior ◽  
Resonance Spectroscopy ◽  
Polycondensation Reaction ◽  
Scanning Calorimetry ◽  
Thermal And Oxidative Stability ◽  
Ft Ir ◽  
C Nmr

Boron-silicon-containing arylacetylene polymer (PBSA) was synthesized through polycondensation reaction among diacetylenebenzene Grignard reagent, boron trichloride and dimethyldichlorosilane, and its structure was characterized by Infrared spectroscopy (FT-IR), Nuclear Magnetic Resonance spectroscopy (13C-NMR). The cure behavior of PBSA was investigated by using Differential Scanning Calorimetry (DSC), and the thermal and oxidative stability of cured PBSA were studied by Thermogravimetric Analysis (TGA) under nitrogen and air, respectively, the results indicated that ceramics derived from PBSA offer high thermal and oxidative stability.

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.

Synthesis and Characterization of Poly (L-Lactic acid) Containing the Azobenzene Mesogens

2011 ◽  
Vol 181-182 ◽  
pp. 185-188
Author(s):  
Run Tao Dong ◽  
Qing Bin Xue ◽  
Ling Min Sun ◽  
Quan Xuan Zhang
Keyword(s):  
Lactic Acid ◽  
Optical Rotation ◽  
Gel Permeation Chromatography ◽  
Helical Structure ◽  
Feed Ratio ◽  
Scanning Calorimetry ◽  
Molecular Weights ◽  
H Nmr ◽  
Azobenzene Mesogens

A series of azobenzene containing group Poly (L-lactic acid) (PLLA) were synthesized by Ring-Opening Polymerization of L-lactide (L-LA) catalysted by Sn (Oct)2initiated by alcohol-OH containing the azobenzene chromophores. Their molecular weights were well controlled by the feed ratio as characterized by Gel Permeation Chromatography (GPC) and1H NMR Spectrometry and agreed well with theoretical values. The thermal properties and liquid crystal phases were investigated by Differential Scanning Calorimetry (DSC), polarized optical microscopy (POM) and X-ray Diffraction (XRS) measurements. Cis-trans photoisomerization behavior of the polymers in the solutions and the films were studied with UV irradiation. By the Circular Dichroism Spectroscopy (CD) characterization of the solutions and films of the polymer, the PLLA segments show huge optical rotation power in helical structure.

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