Biodegradable thermoplastic copolyester elastomers: Methyl branched PBAmT

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 336-345
Author(s):  
Wen-Bo Neng ◽  
Wen-Guang Xie ◽  
Bo Lu ◽  
Zhi-Chao Zhen ◽  
Jun-Long Zhao ◽  
...  
Keyword(s):  
Terephthalic Acid ◽  
Soft Segment ◽  
Amorphous Polymers ◽  
Mechanical Tests ◽  
Random Copolymers ◽  
Feed Ratio ◽  
Methyl Group ◽  
Crystalline Polymers ◽  
H Nmr ◽  
Rigid Segment

Abstract A series of novel biodegradable copolyesters named poly(butylene 3-methyl adipate co-terephthalate) (PBAmT) were synthesized from the monomers of 3-methyl adipic acid (AAm), 1,4-butanediol (BDO), and terephthalic acid (TPA) through a process of esterification and polycondensation. 1H NMR analysis shows that they are random copolymers whose composition can be well controlled by the feed ratio of monomers. From the results of DSC and XRD, the introduction of methyl group successfully destroys the crystallizability of the PBAm chains, thus making it become a relative soft segment compared to PBA, while these random PBAmT copolymers constructed by soft segment PBAm and rigid segment PBT change from semi-crystalline polymers to nearly amorphous polymers as the feed ratio of Am increases. Especially, mechanical tests reveal that the copolymers show outstanding elasticity and rebound resilience with excellent strength. These thermoplastic copolyester elastomers with good performance by simply introduction of branched methyl group on polybutylene adipate terephthalate (PBAT) copolymer chains may well explore the potential application of biodegradable PBAT-based material.

Electrochemically Synthesis and Characterization of Copolymers Based on 1, 4-Diethoxybenzene and 3, 4-Ethylenedioxythiophene

2011 ◽  
Vol 335-336 ◽  
pp. 989-993
Author(s):  
Mi Ouyang ◽  
Zhen Wei Yu ◽  
Yi Xu ◽  
Yu Jian Zhang ◽  
Cheng Zhang
Keyword(s):  
Cyclic Voltammetry ◽  
Ir Spectroscopy ◽  
Feed Ratio ◽  
Synthesis And Characterization ◽  
Monomer Mixture ◽  
Long Wavelength ◽  
H Nmr ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Copolymers based on 1, 4-diethoxybenzene (DEB) and 3, 4-ethylenedioxythiophene (EDOT) were electrochemically synthesized and characterized. The structures of the copolymers were established by 1H NMR and FT-IR spectroscopy. The results indicated the final product was a copolymer instead of a blend or a composite. The physical properties were systematically investigated by cyclic voltammetry, UV-vis absorption and fluorescence. The PL maximum of copolymers presented obviously red-shift to long wavelength as the feed ratio of EDOT in monomer mixture increased.

The Dinitration of Dimethylacetanilides

2003 ◽  
Vol 2003 (5) ◽  
pp. 303-304 ◽  
Author(s):  
Inmaculada C. Rodriguez Medina ◽  
James R. Hanson
Keyword(s):  
Methyl Group ◽  
H Nmr ◽  
Nmr Methods ◽  
Steric Inhibition Of Resonance

The orientation of dinitration of the dimethylacetanilides has been examined by 1H NMR methods and a possible enhancement of the hyperconjugative influence of a methyl group has been considered as an additional factor augmenting the effect of the steric inhibition of resonance on the orientation of substitution.

A Study of Hydrophobically Modified Pullulan Nanoparticles with Different Hydrophobic Densities on the Effect of Anti-Colon Cancer Cell Efficiency

2021 ◽  
Vol 17 (10) ◽  
pp. 1972-1983
Author(s):  
Yi Zhang ◽  
Qing Jiang ◽  
Xinyi Liu ◽  
Liping Peng ◽  
Xinyi Tang ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Structural Properties ◽  
Feed Ratio ◽  
Cell Efficiency ◽  
H Nmr ◽  
Hydrophobically Modified ◽  
Transmission Electron ◽  
A Cell ◽  
And Function ◽  
Hct116 Cells

To discuss the effect of hydrophobic groups of a polymer on the structural properties and function of polymer nanoparticles (NPs), we grafted chenodeoxycholic acid (CDCA) with pullulan (PU) to form hydrophobically modified PU (PUC). Three PUC polymers, namely, PUC-1, PUC-2, and PUC-3, with different degrees of substitution were designed by changing the feed ratio of CDCA and PU. 1H-NMR spectra showed that the PUC polymer was successfully synthesized, and the degrees of hydrophobic substitution for PUC-1, PUC-2, and PUC-3 were calculated to be 10.66%, 13.92%, and 16.94%, respectively. The PUC NPs were prepared by the dialysis method and were shown to be uniformly spherical by transmission electron microscopy (TEM). The average sizes were about (220±10) nm, (203±7) nm, and (163±6) nm under dynamic light scattering (DLS) for PUC-1 NPs, PUC-2 NPs, and PUC-3 NPs, respectively. Drug release experiments showed that the three PUC/DOX NPs exhibited good sustained release. At 48 h, the IC50 of doxorubicin in inhibiting colon cancer HCT116 cells was 0.0904 μg/mL. A cell study showed that PUC-3/DOX NPs had the highest uptake efficiency by HCT116 cells with the most cytotoxicity and inhibited the migration of HCT116 cells with the highest efficiency. The structural properties and function of polymer NPs were closely related to the hydrophobic groups in the polymer, and NPs with higher hydrophobicity showed a smaller size, higher drug capacity, and greater cell efficiency.

scholarly journals Synthesis of Fluorinated Amphiphilic Block Copolymers Based on PEGMA, HEMA, and MMA via ATRP and CuAAC Click Chemistry

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Fatime Eren Erol ◽  
Deniz Sinirlioglu ◽  
Sedat Cosgun ◽  
Ali Ekrem Muftuoglu
Keyword(s):  
Block Copolymer ◽  
Block Copolymers ◽  
Amphiphilic Block Copolymers ◽  
Random Copolymers ◽  
Side Chain ◽  
Dipolar Cycloaddition ◽  
Controlled Synthesis ◽  
H Nmr ◽  
Ft Ir ◽  
Click Coupling

Synthesis of fluorinated amphiphilic block copolymers via atom transfer radical polymerization (ATRP) and Cu(I) catalyzed Huisgen 1,3-dipolar cycloaddition (CuAAC) was demonstrated. First, a PEGMA and MMA based block copolymer carrying multiple side-chain acetylene moieties on the hydrophobic segment for postfunctionalization was carried out. This involves the synthesis of a series of P(HEMA-co-MMA) random copolymers to be employed as macroinitiators in the controlled synthesis of P(HEMA-co-MMA)-block-PPEGMA block copolymers by using ATRP, followed by a modification step on the hydroxyl side groups of HEMA via Steglich esterification to afford propargyl side-functional polymer, alkyne-P(HEMA-co-MMA)-block-PPEGMA. Finally, click coupling between side-chain acetylene functionalities and 2,3,4,5,6-pentafluorobenzyl azide yielded fluorinated amphiphilic block copolymers. The obtained polymers were structurally characterized by1H-NMR,19F-NMR, FT-IR, and GPC. Their thermal characterizations were performed using DSC and TGA.

scholarly journals Synthesis, Characterization, and Antimicrobial Evaluation of Random Poly(ester-Carbonate)s Bearing Pendant Primary Amine in the Main Chain

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2640
Author(s):  
Peng Dong ◽  
Jing Feng ◽  
Sujuan Li ◽  
Tingli Sun ◽  
Qingshan Shi ◽  
...  
Keyword(s):  
Primary Amine ◽  
Ring Opening ◽  
Inhibitory Concentration ◽  
Cyclic Carbonate ◽  
Random Copolymers ◽  
Feed Ratio ◽  
E Coli ◽  
Antimicrobial Evaluation ◽  
Low Cytotoxicity ◽  
Poly Caprolactone

Starting from primary amine bearing cyclic carbonate tert-butyl-(2-oxo-1,3-dioxan-5-yl) carbamate (TBODC) and caprolactone (CL), amphiphilic poly(caprolactone-ran-amino trimethyl carbonate)s (P(CL-ran-ATC)s) random copolymers with controlled molecular weight and composition were synthesized via ring opening polymerization (ROP) and deprotection, using stannous octoate (Sn(Oct)2) as catalyst and benzyl alcohol (BnOH) as initiator. Therefore, hydrophilic/lipophilic ratio (HLR) of the P(CL-ran-ATC)s copolymers can be finely adjusted by the feed ratio of TBODC and CL. The antimicrobial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) of P(CL-ran-ATC)s were proportional to HLR, and P(CL-ran-ATC)s presented more vigorous bactericidal activity towards S. aureus. The minimum inhibitory concentration (MIC) values of P(CL-ran-ATC 50.9%) are 2000 μg mL−1 and 3000 μg mL−1 for S. aureus and E. coli. While P(CL-ran-ATC 50.9%) exhibited deficient hemolytic activity as 1.41%. In addition, the P(CL-ran-ATC)s showed extremely low cytotoxicity towards fibroblast L929 cells.

Research on the Modification of Poly(L-Lactic Acid) by Glucose via Direct Melt Polycondensation

2011 ◽  
Vol 311-313 ◽  
pp. 1106-1109 ◽  
Author(s):  
Shi He Luo ◽  
Shi Qin Yu ◽  
Jian Xiao Li ◽  
Zhao Yang Wang
Keyword(s):  
Drug Delivery ◽  
Lactic Acid ◽  
Feed Ratio ◽  
Biodegradable Material ◽  
Drug Delivery Application ◽  
H Nmr ◽  
Melt Polycondensation ◽  
Molar Feed Ratio ◽  
Direct Melt Polycondensation

Directly using L-lactic acid (L-LA) and glucose (Glu) as the starting materials, novel biodegradable material poly(L-lactic acid-co-glucose) [P(L-LA-co-Glu)] was synthesized via direct melt polycondensation. The copolymers P(L-LA-co-Glu)s at different molar feed ratios were characterized by FTIR,1H-NMR, GPC, DSC and XRD. All poly(L-lactic acid) modified by Glu was partly crystalline. And their Mw, Tm, and crystallinity basically increased with the increase of the molar feed ratio n(L-LA) : n(Glu). When n(Glu) : n(L-LA) was 1 : 750, the biggest Mw was 5900 Da, and all Mwcould meet the requirement for drug delivery application.

Darstellung und Eigenschaften von Derivaten des 4,5-Benzo-2,3-dihydro- \ ,3-diborols/ Synthesis and Properties of Derivatives of the 4,5-Benzo-2,3-dihydro-1,3-diborole

1993 ◽  
Vol 48 (1) ◽  
pp. 68-71 ◽  
Author(s):  
Hartmut Schulz ◽  
Thomas Deforth ◽  
Walter Siebert
Keyword(s):  
Sandwich Complexes ◽  
Methyl Group ◽  
H Nmr ◽  
Derivatives Of

Reactions of 1,2-bis(trimethyIstannyl)benzene (4) with bis(dichIoroboryl)methane derivatives (Cl2B)2CHR1 (R1 = H ,Me) lead to the formation of the 4,5-benzo-1,3-dichloro-2,3-dihydro-1,3-diboroles 2a,b.Substitution of chlorine in 2a,b by a methyl group using A1Me3 yields the 4,5-benzo-1,3-dimethyl-2,3-dihydro-1,3-diboroles 2c,d, of which 2c is thermally labile. Complexation of 2c,d with [(C5H5)Co(C2H4)2] did not give the expected sandwich complexes 6c,d, but the formation of the triple-decker 7d was observed. The paramagnetic 7d and the diamagnetic 7d+, obtained by oxidation with Ag+BF4-, were studied by 1H NMR .

Das dynamische Verhalten des 1-Methyl-1-benzothiepinium-Ringsystems/The Dynamic Behaviour of the 1-Methyl-1-benzothiepinium Ring System

1981 ◽  
Vol 36 (8) ◽  
pp. 974-977 ◽  
Author(s):  
Hans Hofmann ◽  
Franz Dickert
Keyword(s):  
Nmr Spectroscopy ◽  
Room Temperature ◽  
Dynamic Behaviour ◽  
Ring System ◽  
Membered Ring ◽  
Ring Inversion ◽  
Methyl Group ◽  
H Nmr ◽  
Pyramidal Inversion ◽  
Mutual Conversion

Abstract By 1H NMR spectroscopy the stereochemistry of the 1-methyl-1-benzothiepinium ring system was investigated both in thermodynamic and kinetic respects. It was shown that in solution a rapid mutual conversion of the boat shaped seven membered ring system with exo-respectively endo-S-methyl group occurs via a ring inversion and not by a pyramidal inversion at the sulfonium ion. At room temperature predominantly the conformation with the exo-S-methyl group is present.

Proton Magnetic Resonance and Molecular Motion in Solid Methyl-Piperidines and Piperazines

1977 ◽  
Vol 32 (8) ◽  
pp. 882-885 ◽  
Author(s):  
R. Schüler ◽  
L. Brücher ◽  
W. Müller-Warmuth
Keyword(s):  
Proton Magnetic Resonance ◽  
Molecular Motion ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Methyl Group ◽  
Spin Lattice ◽  
H Nmr ◽  
Second Moments ◽  
Line Narrowing

Abstract The 1H-NMR spin-lattice relaxation time and lineshape in solid 2-, 3-, and 4-methyl-piperidine, in 2-and N-methyl-piperazine, and in NN′-diinethyl-piperazine has been measured from low temperatures to the melting point. For all cases, the experimental data can be described by classical rotation of the methyl group. Activation energies governing this motion are between 9 and 14 kJ/mole. Second moments are reduced from about 25 G2 to 17 G2. No further line-narrowing was observed.

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.

Sign in / Sign up

Export Citation Format

Share Document