scholarly journals Some Guidelines for the Synthesis and Melting Characterization of Azide Poly(ethylene glycol) Derivatives

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1269
Author(s):  
Daniel González-Fernández ◽  
Mercedes Torneiro ◽  
Massimo Lazzari
Keyword(s):  
Molecular Weight ◽  
Ethylene Glycol ◽  
Average Molecular Weight ◽  
Size Exclusion ◽  
Degree Of Crystallinity ◽  
Specific Class ◽  
Poly Ethylene Glycol ◽  
End Groups ◽  
Poly Ethylene

We provide fundamental guidelines in the form of a tutorial to be taken into account for the preparation and characterization of a specific class of poly(ethylene glycol) (PEG) derivatives, namely azide-terminated PEGs. Special attention is given to the effect of these chain end groups and their precursors on properties affecting the PEGylation of proteins, nanoparticles and nanostructured surfaces. Notwithstanding the presence of 13C satellite peaks, we show that 1H NMR enables not only the routine quantitative determination of chain-end substitution, but is also a unique method to calculate the absolute number average molecular weight of PEG derivatives. In the use of size exclusion chromatography to get molecular weight distributions, we highlight the importance of distinguishing between eventual secondary reactions involving molecular weight changes and the formation of PEG complexes due to residual amounts of metal cations from reactants. Finally, we show that azide end groups affect PEG melting behavior. In contrast to oxygen-containing end groups, azides do not interact with PEG segments, thus inducing defect formation in the crystal lattice and the reduction of crystal sizes. Melting temperature and degree of crystallinity decrease become especially relevant for PEGs with very low molecular weight, and its comprehension is particularly important for solid-state applications.

Synthesis and Properties of Biodegradable ABA Triblock Copolymers of Polylactide (A) and Polyethylene Glycol (B)

2006 ◽  
Vol 11-12 ◽  
pp. 469-472 ◽  
Author(s):  
Shu Xian Shi ◽  
Yu Zheng Xia ◽  
Xiao Yan Ma ◽  
Shu Ke Jiao ◽  
Xiao Yu Li
Keyword(s):  
Molecular Weight ◽  
Ethylene Glycol ◽  
Ring Opening ◽  
Average Molecular Weight ◽  
Analytical Techniques ◽  
Normal Pressure ◽  
Molar Ratio ◽  
Poly Ethylene Glycol ◽  
Molar Ratios ◽  
Poly Ethylene

The triblock ABA copolymers of poly (D,L-lactide)-b-poly (ethylene glycol)-b-poly (D,L-lactide) (PDLLA-PEG-PDLLA) were synthesized by bulk ring-opening polymerization in the presence of N2 under normal pressure, using the D,L-lactide (DLLA) as monomer, hydroxyl endgroups of poly(ethylene glycol) (PEG) as initiator and the stannous octoate as the catalyst. The resulting copolymers were characterized by various analytical techniques. Effects of molar ratios of lactide to PEG and the chain length of PEG on the viscosity-average molecular weight of the copolymers, the biodegradation behaviors and hydrophilicity of the copolymers were investigated in detail. The results showed that the viscosity-average molecular weight and the contact angle of the copolymers increased with the molar ratio of lactide to PEG, but water uptake and degradability decreased.

scholarly journals Preparation and characterization of double macromolecular network (DMMN) hydrogels based on hyaluronan and high molecular weight poly(ethylene glycol)

2015 ◽  
Vol 3 (32) ◽  
pp. 6618-6625 ◽  
Author(s):  
Changjiang Fan ◽  
Chao Zhang ◽  
Liqiong Liao ◽  
Sheng Li ◽  
Weiping Gan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ethylene Glycol ◽  
Network Structure ◽  
Polymer Network ◽  
Poly Ethylene Glycol ◽  
Double Network ◽  
Macromolecular Network ◽  
Poly Ethylene ◽  
High Molecular Weight Poly

Ultra-strong and resilient double macromolecular network (DMMN) hydrogels with a more evenly distributed polymer network and a double-network structure have been developed.

scholarly journals Production and characterization of poly(3-hydroxybutyrateco-3-hydroxyhexanoate)-poly(ethylene glycol) hybird copolymer with adjustable molecular weight

2011 ◽  
Vol 30 (1) ◽  
pp. 101-111 ◽  
Author(s):  
Ya-li Zhang ◽  
Xiao-yun Lu ◽  
Qian-qian Liu ◽  
Ming-chuan Li ◽  
Zhi-qian Yang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ethylene Glycol ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

scholarly journals Synthesis and Characterizations of Biobased Copolymer Poly(ethylene-co-butylene 2,5-Furandicarboxylate)

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Nam Vu Trung ◽  
Mai Ngoc Nguyen ◽  
Anh Nguyen Thi Ngoc ◽  
Ni Pham Thi ◽  
Tung Tran Quang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ethylene Glycol ◽  
Structural Characterization ◽  
Average Molecular Weight ◽  
Step Process ◽  
Molar Ratios ◽  
Furandicarboxylic Acid ◽  
Poly Ethylene ◽  
Copolymer Poly

Homopolymers and copolymers derived from 2,5-furandicarboxylic acid have been extensively studied for their potential in the development of sustainable plastics. This research definitely spotlighted the synthesis of poly(ethylene-co-butylene 2,5-furandicarboxylate) copolymer via the two-step melting polycondensation with various ethylene glycol/1,4-butanediol molar ratios. The structural characterization of the obtained biobased copolymer was carried out by ATR-FTIR and 1H NMR. The average molecular weight of the obtained copolymer was determined by the intrinsic viscosity measurements. It was found that ethylene glycol was preferentially incorporated into the copolymer structures when the molecular weight of the products was not high enough (>18000). The decomposition of two types of monomer units of the obtained copolymer was proven through the degradation two-step process by TGA measurements.

scholarly journals Synthesis and MALDI-ToF characterization of dendronized poly(ethylene glycol)s

2013 ◽  
Vol 49 (spe) ◽  
pp. 45-55 ◽  
Author(s):  
Brittany K. Myers ◽  
Joanna E. Lapucha ◽  
Scott M. Grayson
Keyword(s):  
Ethylene Glycol ◽  
Poly Ethylene Glycol ◽  
Maldi Tof ◽  
Product Characterization ◽  
End Groups ◽  
Linear Poly ◽  
Mass Spectrometric Approach ◽  
Poly Ethylene ◽  
End Group

Well-defined hybrids of linear poly(ethylene glycol)s (PEGs) and dendritic polyesters were prepared via the dendronization of the alcohol end groups of the mono and difunctional linear PEGs. Though useful for rudimentary product characterization, GPC and NMR could not verify the overall structural purity of these linear-dendritic hybrids. On the other hand, the detailed data provided by MALDI-ToF mass spectrometry enabled confirmation of the high structural purity of the dendronized PEGs at each step of the dendronization procedure. The well-defined number of functionalities on these dendronized PEGs, renders them particularly useful for research in the biomedical sphere where functionality and purity are of the utmost importance. The MALDI-ToF mass spectrometric approach described herein represents a valuable technique for detailed monitoring of these dendronization reactions, as well as a variety of other polymer end group modifications.

scholarly journals Hemocompatibility and swelling studies of poly(2-hydroxyethyl methacrylate-co-itaconic acid-co-poly(ethylene glycol) dimethacrylate) hydrogels

2011 ◽  
Vol 65 (6) ◽  
pp. 675-685 ◽  
Author(s):  
Sava Dobic ◽  
Jovana Jovasevic ◽  
Marija Vojisavljevic ◽  
Simonida Tomic
Keyword(s):  
Molecular Weight ◽  
Ethylene Glycol ◽  
Cell Viability ◽  
Itaconic Acid ◽  
Hydroxyethyl Methacrylate ◽  
Poly Ethylene Glycol ◽  
Swelling Properties ◽  
Swelling Studies ◽  
Poly Ethylene

In this study novel series of hydrogels, based on 2-hydroxyethyl methacrylate (HEMA), itaconic acid (IA) and poly(ethylene glycol) dimethacrylates (PEGDMA) (of varying molecular weight and concentration) were prepared by free radical crosslinking copolymerization. Preliminary hemocompatibility characterization of hydrogels obtained by hemolytic activity assay indicated good compatibility with blood. Preliminary biocompatibility characterization of P(HEMA/IA/PEGDMA) hydrogels, done by the cytotoxicity assays using the HeLa cell line revails that the cell viability of all samples was the range of 97?100%, with no significant decrease in cell viability with the change of PEGDMA molecular weight and concentration. Swelling studies were conducted for all P(HEMA/IA/PEGDMA) samples in a physiological pH and temperature range and network parameters were determined. Swelling studies showed pH sensitive behaviour, typical for anionic hydrogels, and temperature dependent swelling. The effects of concentration of PEGDMA component on hydrogel swelling properties depend on the PEGDMA molecular weight. The samples with 550PEGDMA show different swelling capacities when 550PEGDMA content is changed, whereas for P(HEMA/IA/875PEGDMA) samples there was practically no difference in equilibrium degree of swelling, qe ,with varying 875PEGDMA content, which trend is the same as in the case of qe versus pH dependences. It was concluded that P(HEMA/IA/PEGDMA) hydrogels show good potential to be used as biomedical materials.

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