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 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.

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 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.

A close look at the structural features and reaction conditions that modulate the synthesis of low and high molecular weight fructans by levansucrases

2019 ◽  
Vol 219 ◽  
pp. 130-142 ◽  
Author(s):  
Maria Elena Ortiz-Soto ◽  
Jaime R. Porras-Domínguez ◽  
Jürgen Seibel ◽  
Agustín López-Munguía
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Structural Features ◽  
Reaction Conditions

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 Microdroplet synthesis of azo compounds with simple microfluidics-based pH control

RSC Advances ◽  
2020 ◽  
Vol 10 (64) ◽  
pp. 38900-38905
Author(s):  
Daiki Tanaka ◽  
Shunsuke Sawai ◽  
Shohei Hattori ◽  
Yoshito Nozaki ◽  
Dong Hyun Yoon ◽  
...  
Keyword(s):  
Temperature Control ◽  
Synthesis Method ◽  
Ph Control ◽  
Solution Phase ◽  
Azo Compounds ◽  
Phase Synthesis ◽  
Product Removal ◽  
Solution Phase Synthesis ◽  
High Concentrations ◽  
Conventional Solution

Conventional solution-phase synthesis of azo compounds is complicated by the need for precise pH and temperature control, high concentrations of pH control reagents, and by-product removal. The microdroplet synthesis method has solved these problems.

Novel Templated Polyphenol for Ionic Conductivity

2001 ◽  
Vol 702 ◽  
Author(s):  
Ferdinando F. Bruno ◽  
Ramaswamy Nagarajan ◽  
Jayant Kumar ◽  
Lynne A. Samuelson
Keyword(s):  
Molecular Weight ◽  
Ionic Conductivity ◽  
High Molecular Weight ◽  
Polyethylene Oxide ◽  
Phenol Formaldehyde ◽  
Industrial Applications ◽  
Water Soluble ◽  
Reaction Conditions ◽  
Water Solvent ◽  
Potential Use

ABSTRACTPhenolic polymers and phenol formaldehyde resins are of great interest for a number of electronic and industrial applications. Unfortunately, the toxic nature of the starting materials (formaldehyde) and harsh reaction conditions required for the synthesis of these polymers have severely limited their use in today’s markets. We present here an alternative, biocatalytic approach where the enzyme horseradish peroxidase is used to polymerize phenol in the presence of a template such as polyethylene oxide. Here the template serves as a surfactant that can both emulsify the phenol and polyphenol chains during polymerization and maintain water/solvent solubility of the final polyphenol/template complex. The reactants and the reaction conditions of this approach are mild and result in high molecular weight, electrically and optically active, water-soluble complexes of polyphenol and the template used. High molecular weight water-soluble polyphenol/polyethylene oxide complexes were formed. The ionic conductivity and potential use of these polymers as polyelectrolytes for battery and solution cell applications will be discussed.

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.

scholarly journals A Greener Enzymatic Oligoesterification of Biobased Renewable Synthons

2021 ◽  
Author(s):  
Juan Villavicencio ◽  
Ferley Orozco ◽  
Ricardo Benitez ◽  
Jaime Martin ◽  
Giovanni Rojas
Keyword(s):  
Molecular Weight ◽  
Molar Mass ◽  
Gel Permeation Chromatography ◽  
Scanning Calorimetry ◽  
Reaction Conditions ◽  
Step Process ◽  
Gel Permeation ◽  
One Step ◽  
First Time ◽  
Temperature Time

Polyesters of xylitol and succinic acid were prepared yielding from 70 to 75% by enzymecatalyzed esterification using a molar mass from 1:1 to 2:5 at 120 and 140 °C employing from 1 to 10% m/m of enzyme. Control over branching degree was achieved by tuning the reaction conditions (temperature, time, comonomer ratio, enzyme content). This one-step process from renewable starting materials avoids protection-deprotection techniques, as well as the use of toxic solvents by introducing limonene as solvent for polyesterification for the first time. All materials were structurally characterized by infrared (IR) and nuclear magnetic resonance (NMR)spectroscopy, their thermal properties were studied by differential scanning calorimetry (DSC)and thermogravimetric analysis (TGA), and the molecular weight of samples were obtained by gel-permeation chromatography (GPC).

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