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

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.

2015 ◽  
Vol 216 (6) ◽  
pp. 636-640 ◽  
Author(s):  
Liwei Ren ◽  
Yushen Wang ◽  
Jun Ge ◽  
Diannan Lu ◽  
Zheng Liu

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

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.


2016 ◽  
Vol 7 (34) ◽  
pp. 5445-5455 ◽  
Author(s):  
Ming Yang ◽  
Dongxiong Mao ◽  
Sheng Chen ◽  
Hailiang Zhang

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


2021 ◽  
Vol 2103 (1) ◽  
pp. 012095
Author(s):  
L P Myasnikova ◽  
A K Borisov ◽  
Yu M Boiko ◽  
A P Borsenko ◽  
V F Drobot’ko ◽  
...  

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.


2019 ◽  
Vol 7 (20) ◽  
pp. 3310-3318 ◽  
Author(s):  
Ke Wu ◽  
Samuel P. Douglas ◽  
Gaowei Wu ◽  
Alexander J. MacRobert ◽  
Elaine Allan ◽  
...  

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.


Polymer ◽  
1991 ◽  
Vol 32 (10) ◽  
pp. 1776-1781 ◽  
Author(s):  
Li Hui Wang ◽  
Stefano Ottani ◽  
Roger S. Porter

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Giangiacomo Minak ◽  
Tommaso M. Brugo ◽  
Cristiano Fragassa

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.


2022 ◽  
Author(s):  
Lele Ma ◽  
Jiajian Liu ◽  
Chuncheng Li ◽  
Yaonan Xiao ◽  
Shaohua Wu ◽  
...  

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.


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