scholarly journals Cooligomers from morpholine-2,5-dione and para-dioxanone and catalyst complex SnOct2/2-hydroxyethyl sulfide

MRS Advances ◽  
2021 ◽  
Author(s):  
Xiao Liang ◽  
Marc Behl ◽  
Karola Luetzow ◽  
Andreas Lendlein
Keyword(s):  
Molecular Weight ◽  
Ring Opening ◽  
Building Blocks ◽  
Ring Opening Polymerization ◽  
Molar Ratio ◽  
Feed Ratio ◽  
H Nmr ◽  
Catalyst Complex ◽  
Initiator System ◽  
Specific Number

Abstract Complexes from catalysts and initiator can be used to insert a specific number of additional chemical functional groups in (co)polymers prepared by ring-opening polymerization (ROP) of lactones. We report on the synthesis of cooligomers from sec-butyl-morpholine-2,5-dione (SBMD) and para-dioxanone (PDX) by ROP with varied feed ratios in the bulk using the catalyst complex SnOct2/2-hydroxyethyl sulfide. Mn of the cooligomers (determined by GPC) decreased with decreasing SBMD feed ratio from 4200 ± 420 to 800 ± 80 g mol−1. When the feed ratio was reduced from 80 to 50 mol% the molar ratio of SBMD of the cooligomers (determined by 1H-NMR) remained nearly unchanged between 81 and 86 mol% and was attributed to a higher reactivity of SBMD. This assumption was confirmed by fractionation of GPC, in which an increase of SBMD with increasing molecular weight was observed. The catalyst/initiator system provides a high potential to create orthogonal building blocks by cleavage of the sulfide bond. Graphic abstract

Biodegradable Polymers Derived from Amino Acids for Biological Applications

2010 ◽  
Vol 76 ◽  
pp. 30-35 ◽  
Author(s):  
Naomi Cohen-Arazi ◽  
Ilanit Hagag ◽  
Michal Kolitz ◽  
Abraham J. Domb ◽  
Jeoshua Katzhendler
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Ring Opening ◽  
Building Blocks ◽  
Ring Opening Polymerization ◽  
Microwave Assisted Synthesis ◽  
Hydroxy Acids ◽  
Natural Amino Acids ◽  
Direct Condensation ◽  
Positively Charged

Optically active α-hydroxy acids derived from amino acids have been synthesized and polymerized into new biodegradable polyesters. The variety of functional side chains enables the design of positively charged, negatively charged, hydrophobic and hydrophilic chiral building blocks or any combination of these constituents. Hydroxy acids of 15 natural amino acids were prepared with retention of configuration using a straightforward and reliable method of diazotization of α-amino acids. Polyesters were synthesized from these hydroxy acids by a number of methods: direct condensation in bulk, microwave assisted synthesis and ring opening polymerization. The molecular weight of the prepared polymers ranges between 2000 to 5000Da for the direct condensation and the microwave methods, whereas the ring opening polymerization results in high molecular weight polymers (20000 to 30000Da). The polymers were analyzed for their optical activity (Circular Dichroism Spectroscopy), thermal properties (DSC), solubility, molecular weight and polydispersity (GPC), and aqueous degradation. These polymers were tested for their compatibility to neuronal cells growth and differentiation.

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.

Synthesis and characterization of novel β-cyclodextrin cored poly(α-caprolactone)s by anionic ring opening polymerization

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Yingzhi Guo ◽  
Changjiang Yu ◽  
Zhongwei Gu
Keyword(s):  
Molecular Weight ◽  
Physical Properties ◽  
Ring Opening ◽  
Monomer Conversion ◽  
Ring Opening Polymerization ◽  
Molar Ratio ◽  
Molecular Weights ◽  
Molar Ratios ◽  
Anionic Ring ◽  
Feed Molar Ratio

Abstract By anionic ring opening polymerization initiated by cyclodextrin oxyanions generated from NaH and β-cyclodextrin(β-CD), novel biodegradable β- CD cored star-shaped poly(ε-caprolactone)s (s-PCLs) were synthesized and then characterized by means of FTIR, GPC, 1H-NMR. The effects of different feed molar ratios of NaH and β-CD on arm number and on the molecular weight of s-PCLs, and the relationship between the polymerization time and monomer conversion were investigated. Moreover, the physical properties of linear PCL (l-PCL) and s- PCLs with similar molecular weights but different arm number were studied and compared by DSC, SEM and intrinsic viscosity measurement, respectively. It was found that the feed molar ratio of NaH and β-CD is an important factor which influences both the molecular weight and arm number. The melting points and intrinsic viscosities of s-PCLs with similar molecular weights were lower than that of l-PCL, and were found to decrease with increasing arm number. Both SEM and AFM showed that the surface morphology of s-PCL films was different from that of l-PCL. These results indicated that s-PCL with different arms and physical properties could be synthesized using just a β-CD core by adjusting the feed molar ratio of NaH and β-CD

Synthesis and Characterization of a Novel Biodegradable Polymer with Fluorescence Property

2011 ◽  
Vol 197-198 ◽  
pp. 21-26
Author(s):  
Ji Hang Li ◽  
Dong Jian Shi ◽  
Na Hu ◽  
Wei Fu Dong ◽  
Jun Feng Li ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ring Opening ◽  
Gel Permeation Chromatography ◽  
Ring Opening Polymerization ◽  
Fluorescence Property ◽  
H Nmr ◽  
Gel Permeation ◽  
Fluorescent Polymer ◽  
Poor Solvent

In this paper, a novel biodegradable and fluorescent polymer: fluorescein-polylactide (FL-PLA) was synthesized by FL and lactide in the method of ring-opening polymerization with the catalysis of Sn(Oct)2under 130°C . The structure and molecular weight of FL-PLA were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H-NMR) spectroscopy, and gel permeation chromatography (GPC). The molecular weight of FL-PLA increased from 9.03×103to 21.24×103with decreasing the amount of FL and kept a narrow distribution. The result of differential scanning calorimeter (DSC) showed that Tgincreased from 52 to 72°C with increasing the molecular weight of polymer. Moreover, the average number content of FL in each molecular chain decreased from 0.96 to 0.81 with decrement of the amount of FL. Furthermore, FL-PLA showed the fluorescence property, and the fluorescence intensity could be controlled by the amount of FL. The FL-PLA nanoparticles were prepared by mixing the good and poor solvent, and the diameter was about 3 μm with regular spherical morphology.

scholarly journals Fast and Convenient Synthesis of Amine-Terminated Polylactide as a Macroinitiator forω-Benzyloxycarbonyl-L-Lysine-N-Carboxyanhydrides

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Mingjie Ju ◽  
Feirong Gong ◽  
Shujun Cheng ◽  
Yun Gao
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Low Molecular Weight ◽  
Amine Group ◽  
H Nmr ◽  
Convenient Synthesis ◽  
Ft Ir ◽  
Chain Lengths

Amine-terminated poly (L-lactide) (NH2-PLLA) with various chain lengths were successfully synthesized by sequential tert-butyl-N-(3-hydroxypropyl) carbamate initiated bulk ring-opening polymerization (ROP) of L-lactide (L-LA) in the presence of Stannous(II) 2-ethylhexanoate (Sn(Oct)2) and deprotection of theN-tert-butoxycarbonyl (Boc) group at the end of the polymer chain. The polymers obtained were characterized by FT-IR,1H NMR, and GPC method. NH2-PLLA thus prepared was used to initiate the polymerization of ω-benzyloxycarbonyl-L-lysine-N-carboxyanhydride (Lys (Z)-NCA), and the result confirmed the high nucleophilicity of the terminal amine group. This method was not only suitable for the preparation of low molecular weight NH2-PLLA, but also quite efficient in the synthesis of high molecular weight samples.

Synthesis of Poly L-Glutamate Initiated by Triethanolamine

2012 ◽  
Vol 450-451 ◽  
pp. 26-29
Author(s):  
Zhi Ming Zhang ◽  
Shi Qian Wei ◽  
Ting Ting Li ◽  
Li Hua Han
Keyword(s):  
Glutamic Acid ◽  
Ring Opening ◽  
Raw Materials ◽  
Ring Opening Polymerization ◽  
Benzyl Ester ◽  
Molar Ratio ◽  
Anhydrous Dichloromethane ◽  
H Nmr ◽  
Polymerization Product ◽  
Ubbelohde Viscometer

With L-glutamic acid as raw materials, N-carboxy-L-glutamic acid-benzyl-anhydride (BLG-NCA) was synthesized by triethanolamine. With triethanolamine as the initiator in the anhydrous dichloromethane, ring-opening polymerization of BLG-NCA was initiated, poly-l-glutamic acid benzyl ester was obtained. The amount of initiators, molar ratio of monomer/initiators, reaction temperature and reaction time to the effect of poly-l-glutamic acid benzyl ester in the ring-opening polymerization of BLG-NCA were studied. At last, poly L-glutamate was got, after the debenzylation in HBr solution. Through infrared spectroscopy, Ubbelohde viscometer, 1H NMR spectra, polymerization product was characterized and analysized. Results showed that in dichloromethane, ring-opening polymerization of BLG-NCA could be initiated by triethanolamine.

Synthesis of α,ω-bis(3-aminopropyldiethoxylsilane) Poly(tri fluoropropylmethyl)siloxanes

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Zhendong Shi ◽  
Xinling Wang
Keyword(s):  
Molecular Weight ◽  
Ring Opening ◽  
Reaction Rate ◽  
Ring Opening Polymerization ◽  
Step Process ◽  
Molecular Weights ◽  
H Nmr ◽  
One Step ◽  
Ft Ir ◽  
High Yields

AbstractHigh molecular weight α,ω-bis(3-aminopropyldiethoxylsilane) poly(tri fluoropropylmethyl)siloxanes (APTFPMS) were prepared via a “one-step” process, based on the ring-opening polymerization of 1,3,5-tris(trifluoropropylmethyl) cyclotrisiloxane (F3) in the presence of water and 3-aminopropyltriethoxysilane (APTES). GPC, FT-IR and 1H NMR confirmed the structure of the polymers. It was found that the amount of APTES had significant influence on the reaction rate and the molecular weights of polymers decreased with the increasing amount of water. It was probably because both water and the amino group of APTES favoured generation of hydroxyl ions, which efficiently initiate the polymerization of F3 to achieve APTFPMS. In order to verify this mechanism, another “two-step” process was also performed: Firstly the α,ω-dihydroxylated poly(trifluoropropylmethyl) siloxanes were synthesized from F3 catalyzed by both diaminoethane and water, then reacted with APTES to achieve APTFPMS. All the syntheses had high yields and the molecular weight of the polymers ranged from 2000 to 25000.

Poly(Ethylene Oxide)-B-Poly(ε-Caprolactone) Amphiphilic Block Copolymers: Synthesis and Self-Assembly

2011 ◽  
Vol 284-286 ◽  
pp. 1877-1885
Author(s):  
Ke Xin Kang ◽  
Min Ying Liu ◽  
Qing Xiang Zhao ◽  
Peng Fu ◽  
Xiao Bing Wang
Keyword(s):  
Molecular Weight ◽  
Block Copolymers ◽  
Self Assembly ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Amphiphilic Block Copolymers ◽  
H Nmr ◽  
Transmission Electron ◽  
Particle Size Analyzer ◽  
Anionic Ring

A series of amphiphilic block copolymers mPEO-b-PCL with different PCL molecular weight were successfully prepared by combination of anionic ring-opening polymerization with coordination-insertion ring-opening polymerization. Firstly, the linear mPEO was prepared by anionic ring-opening copolymerization of EO with 2-(2-methoxyethoxy) ethoxide potassium as the small molecule initiators, then the mPEO as the macroinitiator was used to initiate the ring-opening polymerization of CL, in the absence of Sn(Oct)2 as the catalyst, and amphiphilic block copolymers mPEO-b-PCL were obtained. By changing the ratio of monomer and macroinitiator, prepared a series of different molecular weight mPEO-b-PCL. The structure of intermediates and final products were characterized by 1H NMR and GPC. The critical micelle concentration (cmc) of the final copolymer was measured. In addition, the sizes and morphologies of the obtained micelles at different PCL chains were studied with Laser nano-particle size analyzer and transmission electron microscopy (TEM).

scholarly journals Synthesis and characterization of different soybean oil-based polyols with fatty alcohol and aromatic alcohol

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 491-499
Author(s):  
Fukai Yang ◽  
Hao Yu ◽  
Yuyuan Deng ◽  
Xinyu Xu
Keyword(s):  
Molecular Weight ◽  
Soybean Oil ◽  
Retention Time ◽  
Ring Opening ◽  
Isoamyl Alcohol ◽  
Synthesis And Characterization ◽  
Intermolecular Force ◽  
H Nmr ◽  
Epoxy Groups

Abstract In this article, five kinds of soybean oil-based polyols (polyol-E, polyol-P, polyol-I, polyol-B, and polyol-M) were prepared by ring-opening the epoxy groups in epoxidized soybean oil (ESO) with ethyl alcohol, 1-pentanol, isoamyl alcohol, p-tert-butylphenol, and 4-methoxyphenol in the presence of tetrafluoroboric acid as the catalyst. The SOPs were characterized by FTIR, 1H NMR, GPC, viscosity, and hydroxyl numbers. Compared with ESO, the retention time of SOPs is shortened, indicating that the molecular weight of SOPs is increased. The structure of different monomers can significantly affect the hydroxyl numbers of SOPs. Due to the large steric hindrance of isoamyl alcohol, p-hydroxyanisole, and p-tert-butylphenol, SOPs prepared by these three monomers often undergo further dehydration to ether reactions, which consumes the hydroxyl of polyols, thus forming dimers and multimers; therefore, the hydroxyl numbers are much lower than polyol-E and polyol-P. The viscosity of polyol-E and polyol-P is much lower than that of polyol-I, polyol-B, and polyol-M. A longer distance between the molecules and the smaller intermolecular force makes the SOPs dehydrate to ether again. This generates dimer or polymers and makes the viscosity of these SOPs larger, and the molecular weight greatly increases.

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