scholarly journals The Synthesis of Hydroxybutyrate-Based Block Polyurethane from Telechelic Diols with Robust Thermal and Mechanical Properties

2016 ◽  
Vol 2016 ◽  
pp. 1-10
Author(s):  
Dan Xue ◽  
Xiaodong Fan ◽  
Zengping Zhang ◽  
Wei Lv

A series of novel amphiphilic block polyurethanes (PUHE) have been successfully synthesized by solution polymerization of the derived PHB-diol and poly(ethylene glycol) with a coupling agent of 1,6-hexamethylene diisocyanate (HDI), while the PHB-diol was prepared via the transesterification of PHB and ethylene glycol. The hydroxyl contents in PHB-diols range from 1.36 to 1.99 (the molar ratio) as determined by nonaqueous titration. The molecular weight and chemical compositions of PUHE and PHB-diol were investigated by GPC,1H NMR, and FTIR in detail, which confirm the successful synthesis of PUHE. The tensile strength and elongation at break of PUHE could reach as high as 20 MPa and 210%, as the content of PHB in PUHE is 33%. TGA curves indicate that block-bonding between PHB-diol and PEG increases the thermal stability of PHB-diol. Film degradation of PUHE was studied by weight loss and scanning electron microscope (SEM). It could be concluded that degradation occurred gradually from the surface to the inside and that the degradation rate could be controlled by adjusting the PHB/PEG ratios. These properties make PUHE able to be used as a biodegradable thermoplastic elastomer.

2021 ◽  
Vol 873 ◽  
pp. 59-64
Author(s):  
Yang Yi Chen ◽  
Wen Jing Wen ◽  
Zhi Qin Su ◽  
Qi Huan ◽  
Chu Yang Zhang

Thermo-responsive random copolymer poly (2-(2-methoxyethoxy) ethoxyethyl methacrylate-co-poly (ethylene glycol) methyl ether methacrylate), abbreviated as P(MEO2MA-co-OEGMA300) was synthesized by 2-(2-methoxyethoxy) ethoxyethyl methacrylate (MEO2MA) and poly (ethylene glycol) methyl ether methacrylate (OEGMA300) with a molar ratio of 1:1 via atom transfer radical polymerization (ATRP). The structure of P(MEO2MA-co-OEGMA300) was confirmed by 1H NMR and GPC. The transition behaviors of P(MEO2MA-co-OEGMA300) in aqueous solution were investigated by UV-Vis and DLS. While the transition behaviors of P(MEO2MA-co-OEGMA300) thin films were probed by white light interferometry. Compared to the P(MEO2MA-co-OEGMA300) in solution, it shows a much broader transition region, which is a promising candidate for the slow release of drug in the field of medicine.


2016 ◽  
Vol 13 (2) ◽  
pp. 221-234
Author(s):  
Baghdad Science Journal

Different polymers were prepared by condensation polymerization of sebacic anhydride and adipic anhydride with ethylene glycol and poly(ethylene glycol). Their number average molecular weights were determined by end group analysis. Then, they were grafted on the prepared phthalocyaninatocopper(II) compounds with the general formula (NH2)4PcCu(II) having amino groups of 3,3',3'',3'''- or 4,4',4'',4'''- positions. All prepared polymers, compounds, and phthalocyaninatocopper(II)-grafted polymers were characterized by FTIR. The sizing measurements were carried out in 3,3',3'',3'''- (NH2)4PcCu(II) and 4,4',4'',4'''- (NH2)4PcCu(II) compounds with and without grafting polymers. The results showed that the grafting process led to decreasing in particle size and increasing in surface area. The grafting process was reflected positively on the thermal degradation of 3,3',3'',3'''- (NH2)4PcCu(II) and 4,4',4'',4'''- (NH2)4PcCu(II) grafted polymers. They had higher thermal stability accompanied with higher char residue and T50% weight loss with 3,3',3'',3'''-(NH2)4PcCu(II) and their grafted polymers being the best.


2021 ◽  
Vol 873 ◽  
pp. 53-58
Author(s):  
Yang Yi Chen ◽  
Min Pan ◽  
Shan Hong Hu ◽  
Qi Huan ◽  
Chu Yang Zhang

The surface wettability of thermo-responsive random poly (ethylene glycol methyl ether methacrylate-co-triethylene glycol methyl ether methacrylate), abbreviated as P(MEOMA-co-MEO3MA), was investigated in thin film. UV-Vis spectroscopy shows that the LCST of P(MEOMA-co-MEO3MA) with molar ratios of 0:20, 6:14 and 9:11 were 43°C, 32 oC and 25 oC, respectively. LCST shifts towards lower temperature when molar ratio of MEOMA increases. ATR-FTIR indicates that P(MEOMA-co-MEO3MA) thin film experienced a collapse when the temperature passes its LCST. The contact angle of the paraffin oil on the film decreases 15o when the temperature is above its LCST, which confirms the surface wettability can be controlled. Atomic force microscopy shows the surface of the swollen thin film becomes rougher when above it LCST.


2014 ◽  
Vol 1024 ◽  
pp. 136-139 ◽  
Author(s):  
Buong Woei Chieng ◽  
Ibrahim Nor Azowa ◽  
Wan Yunus Wan Md Zin ◽  
Mohd Zobir Hussein

Graphene nanoplatelets (xGnP) were investigated as a novel nanoreinforcement filler in poly (lactic acid)(PLA)/poly (ethylene glycol)(PEG) blends by melt blending method. The prepared nanocomposites exhibited a significant improvement in tensile properties at a low xGnP loading. The tensile properties demonstrated the addition of 0.3wt% of xGnP led to an increase of up to 32.7%, 69.5% and 21.9% in tensile strength, tensile modulus and elongation at break of the nanocomposites respectively, compared to PLA/PEG blend. The nanocomposites also shows enhanced thermal stability compared with PLA/PEG blend in thermogravimetry analysis (TGA). Scanning electron microscopy (SEM) image of PLA/PEG/0.3wt% xGnP displays good uniformity and more homogenous morphology.


2019 ◽  
Vol 944 ◽  
pp. 557-564
Author(s):  
Jia Ming Xu ◽  
Dan Yue Wang ◽  
Han Tong ◽  
Xiao Ze Jiang ◽  
Mei Fang Zhu

Two kinds of diblock copolymers containing glucose and phenylboronic acid moieties, respectively, poly (ethylene glycol)-b-poly (gluconamidoethyl methacrylate) (PEG-b-PGAMA) and poly (ethylene glycol)-b-poly (2-aminoethyl methacrylate-co-3-nitrophenyboronic acid methacrylate) (PEG-b-P(AMA-co-NPBMA)) were synthesized via atom transfer radical polymerization (ATRP) and post polymerization modification (PPM). Well-defined structure and narrow molecular weight distribution of the polymers were confirmed by proton Nuclear Magnetic Resonance (1H NMR) and Gel Permeation Chromatography (GPC). Based on the cross-linking between the diol groups of the glycopolymer and phenylboronic acid under physiological pH (7.4), complex micelles composed of PEG outer shell and boronate ester cross-linking core with a hydrodynamic diameter around 20nm were formed. Morphology, size and assembly behavior of the complex micelles were investigated by 1H NMR, transmission electron microscopy (TEM) and dynamic light scattering (DLS). The results showed the formation/cleavage of boronate ester linkage is reversible upon the variation of solution pH, the complex micelles displayed pH sentiveties of assembling/disassembling behavior. Above pH 7.4, stable spherical micelles can be formed, whereas pH less than 5.5, the micelles dissociated into unimers. Therefore, such pH-responsive micelles based on dynamic complexation of phenyl boronate bonds are expected to be applied to pH-responsive nanodrug carriers


e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Xiang-Hai Ran ◽  
Zhi-Yuan Jia ◽  
Yu-Ming Yang ◽  
Li-Song Dong

AbstractIn this study, plasticized polylactide (PLA) was prepared by blending PLA with high stereoregularity and poly(ethylene glycol-co-propylene glycol) (PEPG) in a batch wise mixer and pressed into films. The influence of annealing temperature on the thermal properties and tensile properties of quenched plasticized PLA was investigated by DSC, DMA and tensile tests. It was found that plasticized PLA after cold crystallization can keep its high flexibility with an elongation at break over 300% by choosing a proper annealing temperature. The difference of crystallization morphology formed at the different annealing temperature was thought as a possible reason for this result.


2017 ◽  
Vol 8 ◽  
pp. 627-635 ◽  
Author(s):  
Jana Lutze ◽  
Miguel A Bañares ◽  
Marcos Pita ◽  
Andrea Haase ◽  
Andreas Luch ◽  
...  

The article describes the synthesis and properties of α-((4-cyanobenzoyl)oxy)-ω-methyl poly(ethylene glycol), the first poly(ethylene glycol) stabilizer for metal nanoparticles that is based on a cyano rather than a thiol or thiolate anchor group. The silver particles used to evaluate the effectiveness of the new stabilizer typically have a bimodal size distribution with hydrodynamic diameters of ca. 13 and ca. 79 nm. Polymer stability was evaluated as a function of the pH value both for the free stabilizer and for the polymers bound to the surface of the silver nanoparticles using 1H NMR spectroscopy and zeta potential measurements. The polymer shows a high stability between pH 3 and 9. At pH 12 and higher the polymer coating is degraded over time suggesting that α-((4-cyanobenzoyl)oxy)-ω-methyl poly(ethylene glycol) is a good stabilizer for metal nanoparticles in aqueous media unless very high pH conditions are present in the system. The study thus demonstrates that cyano groups can be viable alternatives to the more conventional thiol/thiolate anchors.


RSC Advances ◽  
2016 ◽  
Vol 6 (63) ◽  
pp. 58160-58172 ◽  
Author(s):  
Y. Chen ◽  
Y. X. Zhang ◽  
Z. F. Wu ◽  
X. Y. Peng ◽  
T. Su ◽  
...  

The self-assembly and drug release of the three PEG–PCL copolymers with different topologies but identical molar ratio between PEG to PCL.


2009 ◽  
Vol 24 (1) ◽  
pp. 50-57 ◽  
Author(s):  
Chan Woo Kim ◽  
Sung Eun Kim ◽  
Yong Woo Kim ◽  
Hong Jae Lee ◽  
Hyung Woo Choi ◽  
...  

A novel route to organic-inorganic composites was described based on biomineralization of poly(ethylene glycol) (PEG)-based hydrogels. The 3-dimensional hydrogels were synthesized by radical crosslinking polymerization of poly(ethylene glycol fumarate) (PEGF) in the presence of ethylene glycol methacrylate phosphate (EGMP) as an apatite-nuclating monomer, acrylamide (AAm) as a composition-modulating comonomer, and potassium persulfate (PPS) as a radical initiator. We used the urea-mediated solution precipitation technique for biomineralization of hydrogels. The apatite grown on the surface and interior of the hydrogel was similar to biological apatites in the composition and crystalline structure. Powder x-ray diffraction (XRD) showed that the calcium phosphate crystalline platelets on hydrogels are preferentially aligned along the crystallographic c-axis direction. Inductively-coupled plasma mass spectroscopy (ICP-MS) analysis showed that the Ca/P molar ratio of apatites grown on the hydrogel template was found to be 1.60, which is identical to that of natural bones. In vitro cell experiments showed that the cell adhesion/proliferation on the mineralized hydrogel was more pronounced than on the pure polymer hydrogel.


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