scholarly journals Synthesis and characterization of biodegradable aliphatic copolyesters with hydrophilic soft segments

2004 ◽  
Vol 69 (12) ◽  
pp. 1013-1028 ◽  
Author(s):  
Danijela Jovanovic ◽  
Marija Nikolic ◽  
Jasna Djonlagic
Keyword(s):  
Mechanical Analysis ◽  
Transesterification Reaction ◽  
Degree Of Crystallinity ◽  
Solution Viscosity ◽  
Butylene Succinate ◽  
Dynamical Mechanical Analysis ◽  
Soft Segments ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

segmented poly(ester-ether)s based on poly(butylene succinate) and two different types of polyethers were investigated. The poly(ester-ether)s were synthesized by transesterification reaction of dimethyl succinate 1,4-butanediol and poly(ethylene oxide) (PEO, Mn = 1000 g/mol) in the first series, and poly(tetramethylene oxide) (PTMO,Mn = 1000 g/mol) in the second. The mass fraction of soft segments was varied between 10 and 50 mass. %. The effect of the introduction of two different polyether soft segments on the structure, thermal and rheological properties were investigated. The composition of the poly(ester-ether)s, determined from their 1H-NMR spectra showed that incorporation of soft polyether segments was successfully performed by the transesterification reaction in bulk. The molecular weight was estimated from solution viscosity measurements and complex dynamic viscosities. The thermal properties investigated by DSC indicated that the presence of soft segments lowers the melting and crystallization temperature of the hard phase, as well as the degree of crystallinity. Dynamical mechanical analysis was used to investigate the influence of composition on the rheological behavior of the segmented poly(ester-ether)s. The results obtained from an enzymatic degradation test performed on some of the synthesized polymers showed that the biodegradability is enhanced with increasing hydrophilicity.

Preparation and Characterization of PHB/PLLA/PEO Composite Ultra-Fine Fibers via Solution Dry-Spinning Technique

2011 ◽  
Vol 332-334 ◽  
pp. 757-762
Author(s):  
Jiang Hua Du ◽  
Qing Fang Yang ◽  
Xiao Dong Fan
Keyword(s):  
Average Diameter ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Ultrafine Fibers ◽  
Fibril Structure ◽  
Dry Spinning ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Spun Fibers

Poly (3-hydroxybutyrate) (PHB)/poly (L-lactide) (PLLA)/poly (ethylene-oxide) (PEO) composite Ultrafine Fibers were prepared by solution dry spinning technique. Scanning electron microscope (SEM) and X-ray diffraction (XRD) were used to characterize the PHB/PLLA/PEO composite Ultra-fine fibers. In all of the spinning conditions investigated, the average diameter of the as-spun PHB/PLLA/PEO fibers was 2.1 μm and increased with increasing the mass ratio of PHB/PLLA. The degree of crystallinity of as-spun PHB/PLLA/PEO fibers increased with increasing PHB content in their blends, and the α-form crystals of PHB and PLLA in as-spun fibers were obtained. When the mass ration of PHB/PLLA in as-spun PHB/PLLA/PEO fibers was 3:1,the structure of as-spun fibers was the skin-core, which PHB formed core of fibers and PLLA form skin of fibers; when the mass ration of PHB/PLLA in as-spun PHB/PLLA/PEO fibers was 1:1, PLLA and PEO were embedded into PHB phase by droplet and febrile morphology to form matrix-fibril structure of as-spun PHB/PLLA/PEO fibers.

Synthesis and characterization of biodegradable aliphatic copolyesters with poly(ethylene oxide) soft segments

2008 ◽  
Vol 44 (3) ◽  
pp. 904-917 ◽  
Author(s):  
Dragana Pepic ◽  
Ema Zagar ◽  
Majda Zigon ◽  
Andrej Krzan ◽  
Matjaz Kunaver ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Synthesis And Characterization ◽  
Soft Segments ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

scholarly journals Preparation and Characterization of Talc Filled Thermoplastic Polyurethane/Polypropylene Blends

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Emi Govorčin Bajsić ◽  
Vesna Rek ◽  
Ivana Ćosić
Keyword(s):  
Thermal Properties ◽  
Thermoplastic Polyurethane ◽  
Mechanical Analysis ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Polypropylene Blends ◽  
Pp Blends ◽  
The Degree Of Crystallinity ◽  
Better Than

The effect of the addition of talc on the morphology and thermal properties of blends of thermoplastic polyurethane (TPU) and polypropylene (PP) was investigated. The blends of TPU and PP are incompatible because of large differences in polarities between the nonpolar crystalline PP and polar TPU and high interfacial tensions. The interaction between TPU and PP can be improved by using talc as reinforcing filler. The morphology was observed by means of scanning electron microscopy (SEM). The thermal properties of the neat polymers and unfilled and talc filled TPU/PP blends were studied by using dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The addition of talc in TPU/PP blends improved miscibility in all investigated TPU/T/PP blends. The DSC results for talc filled TPU/PP blends show that the degree of crystallinity increased, which is due to the nucleating effect induced by talc particles. The reason for the increased storage modulus of blends with the incorporation of talc is due to the improved interface between polymers and filler. According to TGA results, the addition of talc enhanced thermal stability. The homogeneity of the talc filled TPU/PP blends is better than unfilled TPU/PP blends.

scholarly journals In Situ Dielectric Characterization of Poly(ethylene oxide) Melts Containing Lithium Perchlorate under Steady Shear Flow

2004 ◽  
Vol 37 (18) ◽  
pp. 7064-7064
Author(s):  
Yumi Matsumiya ◽  
Nitash P. Balsara ◽  
John B. Kerr ◽  
Tadashi Inoue ◽  
Hiroshi Watanabe
Keyword(s):  
Shear Flow ◽  
Ethylene Oxide ◽  
Lithium Perchlorate ◽  
Dielectric Characterization ◽  
Steady Shear Flow ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Oxide Melts

scholarly journals Preparation and Characterization of PEBAX-5513/AgBF4/BMIMBF4 Membranes for Olefin/Paraffin Separation

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1550 ◽  
Author(s):  
So Young Kim ◽  
Younghyun Cho ◽  
Sang Wook Kang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Poor Performance ◽  
Amide Group ◽  
Stabilizing Effect ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Scanning Electron

In this study, we investigated a poly(ether-block-amide)-5513 (PEBAX-5513)/AgBF4/1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) composite membrane, which is expected to have a high stabilizing effect on the Ag+ ions functioning as olefin carriers in the amide group. Poly(ethylene oxide) (PEO) only consists of ether regions, whereas the PEBAX-5513 copolymer contains both ether and amide regions. However, given the brittle nature of the amide, the penetration of BMIMBF4 remains challenging. The nanoparticles did not stabilize after their formation in the long-term test, thereby resulting in a poor performance compared to previous experiments using PEO as the polymer (selectivity 3; permeance 12.3 GPU). The properties of the functional groups in the polymers were assessed using Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis, which confirmed that the properties endowed during the production of the film using the ionic liquid can impact the performance.

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