Alternating poly(ester amide)s from glutaric anhydride and α,ω-aminoalcohols: synthesis and thermal properties

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Thomas Fey ◽  
Helmut Keul ◽  
Hartwig Höcker
Keyword(s):  
Molecular Weight ◽  
Thermal Properties ◽  
Homologous Series ◽  
Average Molecular Weight ◽  
Number Average Molecular Weight ◽  
Melting Points ◽  
Glutaric Anhydride ◽  
H Nmr ◽  
Activating Agent ◽  
Dimethylformamide Solution

Abstract Alternating poly(ester amide)s 6a - e were prepared by polycondensation of α-carboxyl-ω-hydroxyamides 3a - e which were obtained by aminolysis of glutaric anhydride (1) and α,ω-aminoalcohols, H2N-(CH2)x-OH (x = 2 - 6) 2a - e. The polycondensation was performed in dimethylformamide solution using a carbodiimide as activating agent, or in bulk with Bu2Sn(OMe)2, Ti(OBu)4 and Sn(octoate)2 as a catalyst. For the polycondensation in bulk, the influence of catalyst and of temperature on the number-average molecular weight was studied. 1H NMR analyses of the poly(ester amide)s clearly show the alternating microstructure. The poly(ester amide)s from glutaric anhydride and the homologous series of α,ω-aminoalcohols are semicrystalline materials; their melting points show the odd/even effect observed for other poly(ester amide)s.

Synthesis and Properties of a Novel Thermostable Polymer: Fluorinated Polycarbodiimide

1997 ◽  
Vol 9 (4) ◽  
pp. 385-395 ◽  
Author(s):  
Amane Mochizukiy ◽  
Michie Sakamotoy ◽  
Masahiro Yoshiokay ◽  
Yuji Hottay ◽  
Takahiro Fukuokay ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Thermal Decomposition ◽  
Dielectric Constant ◽  
Thermal Properties ◽  
Average Molecular Weight ◽  
Number Average Molecular Weight ◽  
Thermostable Polymer ◽  
Lower Dielectric Constant ◽  
Wide Range ◽  
Solution Polycondensation

A new fluorinated linear polycarbodiimide (F-PCD) was synthesized by solution polycondensation of a new fluorinated diisocyanate monomer, 4″, 4″′-(hexafluoroisopropylidene) bis(4-phenoxyphenyl isocyanate) (HPI) in the presence of 3-methyl-1-phenyl-2-phospholene-1-oxide (PMO). HPI was prepared from 4″, 4″′-(hexafluoroisopropylidene)bis(4-phenoxyaniline) (HPA) by three steps. The reaction of HPA with phenyl chloroformate gave the corresponding carbamate, which upon reaction with trimethylsilylchloride (TMS-Cl)-triethylamine (TEA), followed by thermal decomposition, provided HPI. The polymer having a number average molecular weight up to 8400 was obtained in quantitative yield. Thermal properties were investigated and we found that the polymer has a higher glass transition temperature ( Tg)upto 230 °C, and a lower dielectric constant at 2.98 at 1 MHz than the conventional polycarbodiimides (PCDs). The linear F-PCD was soluble in a wide range of common organic solvents such as toluene and dichloromethane.

scholarly journals The Influence of co-catalyst in the Polymerization of 1,3-butadiene Catalyzed by Neodymium Chloride Tripentanolate

2017 ◽  
Vol 60 (3) ◽  
Author(s):  
Luis Alexandro Valencia López ◽  
Francisco Javier Enríquez-Medrano ◽  
Hortensia Maldonado Textle ◽  
Florentino Soriano Corral ◽  
Héctor Ricardo López González ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Catalytic Activity ◽  
Thermal Properties ◽  
Average Molecular Weight ◽  
Number Average Molecular Weight ◽  
Co Catalyst ◽  
Catalytic Activities ◽  
Co Catalysts ◽  
Neodymium Chloride

Triisobutylaluminum (TIBA), triethylaluminum (TEA), di-isobutylaluminum hydride (DIBAH) and methylaluminoxane (MAO) were evaluated as activators of neodymium chloride tripentanolate catalyst in order to investigate their influence over the catalytic activi-ty, macro- and microstructure, and thermal properties of of resulting polybutadienes. The higher catalytic activities were achieved by TEA and TIBA as co-catalysts, whereas TIBA and DIBAH led to the poly-mers with highest cis-1,4 structure content with 98.4 and 97.3% re-spectively. The catalytic activity was remarkably poor with MAO as co-catalyst, as well as low stereocontrol. Number average molecular weight values were observed in the range of 260 to 720 kg/mol.

The Syntheses and Mark-Houwink Empirical Formula of Polysiloxanes Containing Cyanoethyl Groups as Side Substituents

2011 ◽  
Vol 239-242 ◽  
pp. 2765-2768
Author(s):  
Rui Fang Guan ◽  
Jian Rong Wang ◽  
Yu Rong Dong
Keyword(s):  
Molecular Weight ◽  
Empirical Formula ◽  
Average Molecular Weight ◽  
New Method ◽  
Number Average Molecular Weight ◽  
H Nmr ◽  
Ft Ir

Polysiloxanes containing cyanoethyl groups (PDMS-CN) is a useful functional polysiloxanes. In this paper a new method was employed to prepare the polysiloxane with various number average molecular weight (Mn) and cyanoethyl groups. Mns of PDMS-CN were determined by GPC and the relationships between the instrinsic viscosity ([η]) and Mn of PDMS-CN were given. The contents of cyanoethyl groups were determined by FT-IR and 1H NMR.

Chemistry and Properties of Imide Oligomers from Phenylethynyl-Containing Diamines

2000 ◽  
Vol 12 (1) ◽  
pp. 213-223 ◽  
Author(s):  
J G Smith ◽  
J W Connell
Keyword(s):  
Thin Films ◽  
Molecular Weight ◽  
Research Effort ◽  
Average Molecular Weight ◽  
Number Average Molecular Weight ◽  
Similar Composition ◽  
Imide Oligomers ◽  
Calculated Number

As an extension of work on pendent phenylethynyl-containing imide oligomers, three new diamines containing pendent phenylethynyl groups were prepared and characterized. These diamines were used to prepare pendent and pendent and terminal phenylethynyl imide oligomers via the amide acid route in N-methyl-2-pyrrolidinone at a calculated number average molecular weight of 5000 g mol−1. The pendent phenylethynyl groups were randomly distributed along the oligomer backbone and provided a means of controlling the distance between reactive sites. The imide oligomers were characterized and thermally cured, and the cured polymers evaluated as thin films and compared with materials of similar composition prepared from 3,5-diamino-4′-phenylethynylbenzophenone. This work was performed as part of a continuing research effort to develop structural resins for potential aeronautical applications.

Synthesis and thermal properties of triblock copolymers of methyl methacrylate using combination of anionic and controlled radical polymerization: Poly(methyl methacrylate) center block bearing different microstructures

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhengji Song ◽  
Carole Pelletier ◽  
Yinghua Qi ◽  
Jasim Ahmed ◽  
Sunil K. Varshney ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Thermal Properties ◽  
Block Copolymers ◽  
Methyl Methacrylate ◽  
Radical Polymerization ◽  
Triblock Copolymers ◽  
Controlled Radical Polymerization ◽  
Alkyl Methacrylate ◽  
Poly Methyl Methacrylate ◽  
H Nmr

AbstractABA and/or ABC type triblock copolymers were synthesized by living anionic and controlled radical polymerization in which poly(methyl methacrylate) was used as central block. The structural composition of these block copolymers were determined by 1H NMR. The block length/molecular weight and microstructure of these polymers were measured by SEC. The microstructure of resultant central alkyl methacrylate block can be tailored from highly syndiotactic to highly isotactic structure by varying the solvent and/or initiator. The thermal and rheological properties of center poly(methyl methacrylate) block and poly(styreneb- methyl methacrylate-b- styrene) tri block copolymers were studied in detail.

Study on the Reaction of TDI and PPG with Organo-Tin Mixed Catalyst

2011 ◽  
Vol 418-420 ◽  
pp. 13-17
Author(s):  
Su Ran Liao ◽  
Yuan Wei ◽  
Yu Qi Zhang ◽  
Meng Zhang ◽  
Gao Fei Feng
Keyword(s):  
Molecular Weight ◽  
Hydrogen Bonding ◽  
Average Molecular Weight ◽  
Polypropylene Glycol ◽  
Number Average Molecular Weight ◽  
Mixed Catalyst ◽  
Back Titration ◽  
Step Growth ◽  
Step Growth Polymerization ◽  
Polymerization Conditions

The study of polyurethanes are of continuing interest due to their excellent physical properties. In this study, the reaction kinetics and polymerization conditions in two-step process of toluene diisocyante (TDI) and polypropylene glycol (PPG) with organo-tin mixed catalyst were investigated by di-n-butylamine back-titration. It was showed that the reaction obeyed the second-order equation of step-growth polymerization, the rate constants of TDI and PPG reaction at 50, 60 and 70°C were 0.0922, 0.3373 and 0.5828 kg•mol-1•min-1，respectively. The activation energy obtained from the result was 71.63 kJ•mol-1. The number average molecular weight (Mn) and molecular-weight distribution (Mw/Mn) of the polyurethane were 45175 and 1.53, respectively, and the content of hydrogen bonding in the N-H group from Fourier transform infrared spectrum (FTIR) was 80.75%, which manifested that the large amount of N-H were present in hydrogen bonding.

scholarly journals The presence of a high-molecular-weight (guanine-plus-cytosine)-rich segment at the 3' end of rabbit 28S ribosomal ribonucleic acid.

1975 ◽  
Vol 147 (3) ◽  
pp. 625-628 ◽  
Author(s):  
A A Hadjiolov ◽  
R A Cox ◽  
P Huvos
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Ribonucleic Acid ◽  
Average Molecular Weight ◽  
28S Rrna ◽  
Number Average Molecular Weight ◽  
Ribonuclease T1 ◽  
Naphthoic Acid ◽  
Rrna Molecule ◽  
Ribosomal Ribonucleic Acid

The 3′ hydroxyl end of 28S L-rRNA (major RNA species of the larger subribosomal particle) was labelled by coupling its 2-hydroxy-3-naphthoic acid hydrazine with diazotized [3H]aniline. The RNA was hydrolysed partially with ribonuclease T1 and fractionated on Sephadex G-200. The results show that a highly structured segment with 78% G+C content and a number-average molecular weight of at least 1.0×10(5)-1.8×10(5) is located at the 3′ hydroxyl end of the 28S rRNA molecule.

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