Design, synthesis and thermotropic self-organization of dendronized polystyrenes with different length alkyl tails

2016 ◽  
Vol 7 (34) ◽  
pp. 5445-5455 ◽  
Author(s):  
Ming Yang ◽  
Dongxiong Mao ◽  
Sheng Chen ◽  
Hailiang Zhang
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Self Organization ◽  
Design Synthesis ◽  
First Time

A reentrant phase is observed for the first time in dendronized polystyrenes with high molecular weight through regulating the length of tail chains.

scholarly journals Characterization of a Novel Fructosyltransferase from Lactobacillus reuteri That Synthesizes High-Molecular-Weight Inulin and Inulin Oligosaccharides

2002 ◽  
Vol 68 (9) ◽  
pp. 4390-4398 ◽  
Author(s):  
S. A. F. T. van Hijum ◽  
G. H. van Geel-Schutten ◽  
H. Rahaoui ◽  
M. J. E. C. van der Maarel ◽  
L. Dijkhuizen
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Lactobacillus Reuteri ◽  
Bacterial Strains ◽  
Potential Health ◽  
Isolation And Characterization ◽  
A Cell ◽  
Encoding Gene ◽  
First Time

ABSTRACT Fructosyltransferase (FTF) enzymes produce fructose polymers (fructans) from sucrose. Here, we report the isolation and characterization of an FTF-encoding gene from Lactobacillus reuteri strain 121. A C-terminally truncated version of the ftf gene was successfully expressed in Escherichia coli. When incubated with sucrose, the purified recombinant FTF enzyme produced large amounts of fructo-oligosaccharides (FOS) with β-(2→1)-linked fructosyl units, plus a high-molecular-weight fructan polymer (>107) with β-(2→1) linkages (an inulin). FOS, but not inulin, was found in supernatants of L. reuteri strain 121 cultures grown on medium containing sucrose. Bacterial inulin production has been reported for only Streptococcus mutans strains. FOS production has been reported for a few bacterial strains. This paper reports the first-time isolation and molecular characterization of (i) a Lactobacillus ftf gene, (ii) an inulosucrase associated with a generally regarded as safe bacterium, (iii) an FTF enzyme synthesizing both a high molecular weight inulin and FOS, and (iv) an FTF protein containing a cell wall-anchoring LPXTG motif. The biological relevance and potential health benefits of an inulosucrase associated with an L. reuteri strain remain to be established.

scholarly journals The nanostructuring of ultra-high-molecular-weight polyethylene in thermal and mechanical fields as revealed by DSC

2021 ◽  
Vol 2103 (1) ◽  
pp. 012095
Author(s):  
L P Myasnikova ◽  
A K Borisov ◽  
Yu M Boiko ◽  
A P Borsenko ◽  
V F Drobot’ko ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Melting Temperature ◽  
Mechanical Characteristics ◽  
Thickness Distribution ◽  
High Strength ◽  
High Modulus ◽  
Know How ◽  
First Time ◽  
Ultra High Molecular Weight

Abstract The ultra-high-molecular-weight polyethylene reactor powders are widely used for the actively developing solvent-free method for producing high-strength high-modulus PE filaments, which includes the compaction and sintering of a powder followed by orientational hardening. To find an appropriate regime of the technological process, it is important to know how the nanostructure changes when transforming from a powder to a precursor for hardening. Nanocrystalline lamellae are characteristics of the powder structure. For the first time, the DSC technique was used to follow changes in the thickness distribution of lamellae in ultra-high-molecular-weight polyethylene reactor powder on its way to a precursor for orientation hardening. It was found that the percentage of thick (>15 nm) and thin (10 nm) lamellae in compacted samples and those sintered at temperatures lower than the melting temperature of PE (140°C) remains nearly the same. However, significant changes in the content of lamellae of different thicknesses were observed in the samples sintered at 145°C with subsequent cooling under different conditions. The influence of the lamellae thickness distribution in precursors on the mechanical characteristics of oriented filaments was discussed.

scholarly journals A rugged, self-sterilizing antimicrobial copper coating on ultra-high molecular weight polyethylene: a preliminary study on the feasibility of an antimicrobial prosthetic joint material

2019 ◽  
Vol 7 (20) ◽  
pp. 3310-3318 ◽  
Author(s):  
Ke Wu ◽  
Samuel P. Douglas ◽  
Gaowei Wu ◽  
Alexander J. MacRobert ◽  
Elaine Allan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Copper Coating ◽  
Prosthetic Joint ◽  
Preliminary Study ◽  
First Time ◽  
Ultra High Molecular Weight ◽  
Joint Material

We report here for the first time how a copper coating bond to ultra-high molecular weight polyethylene (UHMWPE) via low temperature aerosol assisted chemical vapour deposition.

scholarly journals Ultra-High-Molecular-Weight Polyethylene Rods as an Effective Design Solution for the Suspensions of a Cruiser-Class Solar Vehicle

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Giangiacomo Minak ◽  
Tommaso M. Brugo ◽  
Cristiano Fragassa
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Design Solution ◽  
Design And Optimization ◽  
Suspension Systems ◽  
Proper Design ◽  
Material Solution ◽  
First Time ◽  
Ultra High Molecular Weight

Ultra-high-molecular-weight polyethylene (UHMWPE) is a subgroup of the thermoplastic polyethylene characterized by extremely long chains and, as result, in a very tough and resistant material. Due to remarkable specific mechanical properties, its use is gradually being extended to multiple fields of application. This study describes, perhaps for the first time, how the UHMWPE can represent a valid material solution in the design and optimization of suspensions for automotive use, especially in the case of extremely lightweight vehicles, such as solar cars. In particular, in this design study, UHMWPE rods permitted to assure specific kinematic trajectories, functionalities, and overall performance in an exceptionally light suspension systems, developed for an innovative multioccupant solar vehicle. These rods reduced the weight by 88% with respect to the classic design solutions with similar functions, offering, at the same time, high stiffness and accuracy in the movements. An experimental campaign was conducted to evaluate the ratcheting behaviour and other mechanical properties needed for a proper design and use.

A facile and economical method to synthesize a novel wide gamut fluorescent copolyester with outstanding properties

2022 ◽  
Author(s):  
Lele Ma ◽  
Jiajian Liu ◽  
Chuncheng Li ◽  
Yaonan Xiao ◽  
Shaohua Wu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Uv Light ◽  
Green Fluorescence ◽  
Economical Method ◽  
First Time

A series of high molecular weight copolyesters PExBTyAm were synthesized by a simple and economical two-step polycondensation method, and for the first time we found that the copolyesters exhibited an green fluorescence under 365 nm UV light.

Electrospinning of Ultrahigh-Molecular-Weight Polyethylene Nanofibers

2008 ◽  
Vol 1083 ◽  
Author(s):  
Dmitry M. Rein ◽  
Yachin Cohen ◽  
Avner Ronen ◽  
Eyal Zussman ◽  
Kim Shuster
Keyword(s):  
Molecular Weight ◽  
Dielectric Constant ◽  
Elevated Temperature ◽  
High Molecular Weight ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Ultrahigh Molecular Weight ◽  
Electrospinning Method ◽  
Surface Modified ◽  
First Time ◽  
Ultra High Molecular Weight

ABSTRACTThe electrospinning method was employed to fabricate extremely fine nanofibers of ultra-high molecular weight polyethylene (UHMWPE) for the first time, using a mixture of solvents with different dielectric constant and conductivity. A novel experimental device for elevated temperature electrospinning of highly volatile and quickly crystallizing polymer solutions and melts was developed. The possibility to produce the highly oriented nanofibers from ultra-high molecular weight polymers suggests new ways for fabrication of ultra-strong, porous, surface modified fibers and single-component nanocomposite yarn with improved properties.

scholarly journals Facile Synthesis of High Molecular Weight Polypeptides via Surface-Initiated Vapor Deposition Polymerization

2018 ◽  
Author(s):  
Chih-Tsung Yang ◽  
Jen-Chia Wu ◽  
Ying-Chih Chang
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Vapor Deposition ◽  
Reaction Conditions ◽  
Phase Synthesis ◽  
Resin Beads ◽  
Solution Phase Synthesis ◽  
Synthetic Polypeptides ◽  
Conventional Solution ◽  
First Time

Despite huge effort has been devoted to the design of the initiators and reaction conditions, it remains challenging to synthesize high molecular weight polypeptides with conventional solution phase synthesis. In this work, surface-initiated vapor deposition polymerization (SI-VDP) was utilized to graft synthetic polypeptides poly (γ-benzyl L-glutamate) (PBLG) from polystyrene (PS) resin beads by ring-opening polymerization of N-carboxyanhydrides (NCAs). It was demonstrated for the first time that high molecular weight bulk PBLG (> 500,000) could be readily obtained within one hour via solvent-free synthetic method which paves the way for the synthesis of copolypeptides with high molecular weight.

scholarly journals Enzymatic synthesis of an electrospinnable poly(butylene succinate-co-dilinoleic succinate) thermoplastic elastomer

RSC Advances ◽  
2017 ◽  
Vol 7 (34) ◽  
pp. 21258-21267 ◽  
Author(s):  
Agueda Sonseca ◽  
Miroslawa El Fray
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Enzymatic Synthesis ◽  
Diphenyl Ether ◽  
Thermoplastic Elastomer ◽  
Candida Antarctica ◽  
Two Stage ◽  
Butylene Succinate ◽  
Diethyl Succinate ◽  
First Time

Candida antarcticalipase B was successfully employed for the first time as a biocatalyst to obtain high molecular weight PBS : DLS copolyesterviaa two-stage method in diphenyl ether from diethyl succinate, 1,4-butanediol, and dimer linoleic diol.

Isolation of size homogeneous preparations of high molecular weight and low molecular weight fibrinogens

1981 ◽  
Vol 59 (5) ◽  
pp. 332-342 ◽  
Author(s):  
Hannah M. Phillips
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Molecular Sizes ◽  
Carboxyl Terminal ◽  
First Time ◽  
Molecular Weight Form

Molecular sizes of fibrinogen (F) similar to FI, higher molecular weight form, and FII, lower molecular weight form, have been found by Lipinska and colleagues. A procedure has been developed to isolate for the first time each of the FI and FII forms of fibrinogen which are free of each other and of high molecular weight fibrin–fibrinogen complexes. This process involved removing the complexes by A-5 m chromatography. This chromatography also reduced a protein contaminant (X) and removed plasminogen. (NH4)2SO4 subfractionation at pH 5.9 was then done. A subtraction (16–18%) containing 90% FI and another (22–25% or 25–28%) containing 96% FII were obtained. Reprecipitation of the first 16–18% subfraction yielded a subfraction containing 97% FI. Sodium dodecyl sulfate (SDS) – polyacrylamide gel electrophoresis of FII revealed that it contains one intact Aα chain per (Bβ, γ)2. Clot opacity studies on FII suggested that the carboxyl terminal portion of the α chain of fibrin plays an important role in the lateral associations in fibrin polymerization.Also, the pattern of (NH4)2SO4 precipitation of the endogenous fibrin–fibrinogen complexes was studied. This revealed that the complexes precipitated mostly in the least soluble subfractions, but small amounts could be found in all subfractions. Examination of the complexes by SDS–polyacrylamide gel electrophoresis showed that most of the complexes could be dissociated to FI and FII. However, there were complexes which remained and these were found to be covalently cross-linked forms probably produced by factor XIII.

scholarly journals Phage Tail-Like (High-Molecular-Weight) Bacteriocins of Budvicia aquatica and Pragia fontium (Enterobacteriaceae)

2005 ◽  
Vol 71 (12) ◽  
pp. 8970-8973 ◽  
Author(s):  
Jan Šmarda ◽  
Oldřich Benada
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Microscopic Analysis ◽  
Electron Microscopic Analysis ◽  
Electron Microscopic ◽  
Simultaneous Production ◽  
Phage Tail ◽  
First Time

ABSTRACT Electron microscopic analysis of contractile phage tail-like bacteriocins of three Pragia fontium strains and one Budvicia aquatica strain was performed. Fonticin and aquaticin are remarkably heat sensitive but trypsin resistant. Simultaneous production of contractile and flexible phage tail-like bacteriocins in the P. fontium 64613 strain is shown for the first time.

Sign in / Sign up

Export Citation Format

Share Document