scholarly journals Synthesis and Structural Characterization of Sequential Structure and Crystallization Properties for Hydrophilic Modified Polyester

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1733
Author(s):  
Lina Sun ◽  
Liqian Huang ◽  
Xueli Wang ◽  
Hongmei Hu ◽  
Juanzi Guo ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Molar Ratio ◽  
Random Copolymers ◽  
Feed Ratio ◽  
Degradation Temperature ◽  
Sequential Structure ◽  
Melt Polycondensation ◽  
Polycondensation Process ◽  
Isothermal Kinetic

The hydrophilic copolyester polyethylene terephthalate (PET) (ENCDP-X) was successfully synthesized by chemical modification consisting of copolymerization and blending and the comonomers, including sodium isophthalate-5-sulfonate (SIPE), polyethylene glycol (PEG), 2,2-dimethyl-1,3-propanediol (NPG) and matting agent TiO2 with different content. Moreover, the structural characterization of sequential structure, crystallization and thermal properties were studied. The results showed that the comonomers were successfully embedded in the copolyester, the actual molar ratio in the copolyester was consistent with the relative feed ratio and the degree of randomness was calculated to be 0.99, showing that the random copolymers synthesized during the melt polycondensation process and the chemical structure was roughly consistent with the expected molecular chain sequence structure. The thermal parameters of the modified copolyester, containing the glass transition temperature (Tg), melting point (Tm), crystallinity (Xc) and thermal degradation temperature, were decreased, and the cold crystallization temperature (Tc) was increased. In addition, with the increasing of the TiO2 content, it improves the thermal performance of the copolyester and it is beneficial to processing and application. The above conclusion is further verified by non-isothermal kinetic analysis. In addition, the copolyester exhibited the better hydrophilicity than pure PET.

Synthesis and structural characterization of zinc complexes of the imido–amido phosphate anions OP[(NHR)3–x(NR)]x– (R = Me, t-Bu; x = 1–3) and EP[(NH-t-Bu)2(N-t-Bu)]– (E = S, NSiMe3)

2005 ◽  
Vol 83 (10) ◽  
pp. 1768-1778 ◽  
Author(s):  
Andrea F Armstrong ◽  
Tristram Chivers ◽  
Mark Krahn ◽  
Masood Parvez
Keyword(s):  
Nmr Spectroscopy ◽  
Structural Characterization ◽  
Zinc Phosphate ◽  
Membered Ring ◽  
Molar Ratio ◽  
Centrosymmetric Dimer ◽  
X Ray ◽  
Phosphate Anions ◽  
New Compounds

The reaction of OP(NH-t-Bu)3 with 1 equiv. of ZnMe2 generates the dimeric eight-membered ring {MeZn[(µ-NH-t-Bu)(µ-N-t-Bu)P(NH-t-Bu)(µ-O)]}2 (5) and the cubane {[MeZn]3[OP(N-t-Bu)3][OP(NH-t-Bu)3]} (6), which contains the first known trisimidophosphate trianion. A related complex {Zn[ZnMe]2[OP(N-t-Bu)(NH-t-Bu)2][OP(N-t-Bu)3]} (7) is obtained by the reaction of OP(NH-t-Bu)3 with ZnMe2 in a 2:3 molar ratio. The treatment of OP(NHMe)3 with 1 equiv. of ZnMe2 produces the oxide-templated cluster {Zn4(µ4-O)[OP(NMe)(NHMe)2]4[OP(NMe)2(NHMe)]}2 (8). Each half of this centrosymmetric dimer contains a tetrahedral arrangement of four 4-coordinate Zn2+ ions surrounding the central µ4-O2- anion. The reaction of SP(NH-t-Bu)3 with ZnMe2 in a 1:1 molar ratio generates the dimer {MeZn(µ-S)(µ-N-t-Bu)P(NH-t-Bu)2}2 (10), which has a ladder-type structure. When a 2:1 molar ratio of the same reagents is employed, the bis(N,S)-chelated complex {Zn[(µ-S)(µ-N-t-Bu)P(NH-t-Bu)2]2} (11) is obtained. The monomeric N,N′-chelated complex {MeZn[(µ-N-t-Bu)(µ-NSiMe3)P(NH-t-Bu)2]} (12) results from the reaction of Me3SiNP(NH-t-Bu)3 with 1 equiv. of dimethylzinc. All new compounds have been characterized by multinuclear (1H, 13C, and 31P) NMR spectroscopy and, in the case of 5, 6, 7, 8, and 10, by X-ray structural determinations.Key words: zinc, phosphate, imido ligands, sulfur.

Synthesis and Characterization of Branched Poly(Ethylene Terephthalate)

2013 ◽  
Vol 815 ◽  
pp. 738-741
Author(s):  
Yan Ming Chen ◽  
Dan Zhao ◽  
Li Yan Wang ◽  
Quan Cai Wu
Keyword(s):  
Terephthalic Acid ◽  
Ethylene Terephthalate ◽  
Raw Materials ◽  
Synthesis And Characterization ◽  
Melt Polycondensation ◽  
Poly Ethylene Terephthalate ◽  
Polyfunctional Monomer ◽  
Polycondensation Process ◽  
Poly Ethylene

Linear and branched poly (ethylene terephthalate) were prepared by using terephthalic acid, ethylene glycol as main raw materials and pentaerythritol as polyfunctional monomer through melt polycondensation method. The samples were characterized with respect to intrinsic viscosity and differential scanning calorimeter (DSC). The results show that the low branched poly (ethylene terephthalate) could be obtained by the addition of tertrafunctional pentaerythritol through common melt polycondensation process.

scholarly journals Formation and structural characterization of a europium(II) mono(scorpionate) complex and a sterically crowded pyrazabole

2017 ◽  
Vol 73 (12) ◽  
pp. 1921-1925 ◽  
Author(s):  
Phil Liebing ◽  
Marcel Kühling ◽  
Josef Takats ◽  
Liane Hilfert ◽  
Frank T. Edelmann
Keyword(s):  
Single Crystal ◽  
Structural Characterization ◽  
Molar Ratio ◽  
High Yield ◽  
X Ray Diffraction ◽  
Isopropyl Group ◽  
X Ray

The reaction of EuI2(THF)2with potassium hydrotris(3,5-diisopropylpyrazolyl)borate (K[HB(3,5-iPr2pz)3] (= KTpiPr2, pz = pyrazolyl) in a molar ratio of 1:1.5 resulted in extensive ligand fragmentation and formation of the europium(II) mono(scorpionate) complex bis(3,5-diisopropyl-1H-pyrazole)[hydrotris(3,5-diisopropylpyrazolyl)borato]iodidoeuropium(II), [Eu(C27H46BN6)I(C9H16N2)2] or (TpiPr2)(3,5-iPr2pzH)2EuIII,1, in high yield (78%). As a typical by-product, small amounts of the sterically crowded pyrazabole derivativetrans-4,8-bis(3,5-diisopropylpyrazol-1-yl)-1,3,5,7-tetraisopropylpyrazabole, C36H62B2H8ortrans-{(3,5-iPr2pz)HB(μ-3,5-iPr2pz)}2,2, were formed. Both title compounds have been structurally characterized through single-crystal X-ray diffraction. In1, two isopropyl groups are each disordered over two orientations with occupancy ratios of 0.574 (10):0.426 (10) and 0.719 (16):0.281 (16). In2, one isopropyl group is similarly disordered, occupancy ratio 0.649 (9):0.351 (9).

New ultrastructural findings about Borrelia burgdorferi by cryofixation, negative staining, thin sectioning and scanning techniques

1990 ◽  
Vol 48 (3) ◽  
pp. 582-583
Author(s):  
S. F. Hayes ◽  
M. D. Corwin ◽  
T. G. Schwan ◽  
D. W. Dorward ◽  
W. Burgdorfer
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Structural Characterization ◽  
Negative Staining ◽  
Low Speed ◽  
Thin Sectioning ◽  
Ultrastructural Findings

Characterization of Borrelia burgdorferi strains by means of negative staining EM has become an integral part of many studies related to the biology of the Lyme disease organism. However, relying solely upon negative staining to compare new isolates with prototype B31 or other borreliae is often unsatisfactory. To obtain more satisfactory results, we have relied upon a correlative approach encompassing a variety EM techniques, i.e., scanning for topographical features and cryotomy, negative staining and thin sectioning to provide a more complete structural characterization of B. burgdorferi.For characterization, isolates of B. burgdorferi were cultured in BSK II media from which they were removed by low speed centrifugation. The sedimented borrelia were carefully resuspended in stabilizing buffer so as to preserve their features for scanning and negative staining. Alternatively, others were prepared for conventional thin sectioning and for cryotomy using modified procedures. For thin sectioning, the fixative described by Ito, et al.

Structural characterization of the PPIase domain of FKBP51, a cochaperone of human Hsp90

2011 ◽  
Vol 44 (06) ◽  
Author(s):  
A Bracher ◽  
C Kozany ◽  
AK Thost ◽  
F Hausch
Keyword(s):  
Structural Characterization ◽  
Ppiase Domain

Structural characterization of dendrobine-type sesquiterpene alkaloids from the stems of Dendrobium nobile using LC-MS/MS

Planta Medica ◽  
2014 ◽  
Vol 80 (10) ◽  
Author(s):  
YH Wang ◽  
B Avula ◽  
N Abe ◽  
F Wei ◽  
M Wang ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Dendrobium Nobile
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