10 research outputs found
Novel Enzymatic Synthesis of 3-hydroxybutyric Acid Oligomerswith Inserted Lactobionic Acid Moieties
3-Hydroxybutyric acid and lactobionic acid yielded linear and cyclic oligomers in a lipase-catalyzedcondensation polymerization reaction, performed at 80°C in bulk and organic solvent systems. Novozyme435 was the most efficient biocatalyst, and a mixture of t-butanol and dimethylsulfoxide in 80:20 (v/v) ratioprovided the highest copolymer conversions. The highest degree of polymerization reached 7 in case ofcopolymers with inserted lactobionic acid moiety and 11 for the 3-hydroxybutyric acid homopolymer by-product
Fényemittáló és nagyspinű polimerek előállítása és vizsgálata = Synthesis and characterization of light emitting and high-spin polymers
Glükozilezett naftalén-fenilén típusú kopolimert állítottunk elő Suzuki-polikondenzációval. A kopolimer kék fényt emittált és önszerveződő tulajdonságokat mutatott mind oldat, mind szilárd fázisban. Kék fényt emittáló egyforma méretű nanogömbök képződését figyeltük meg. Potenciálisan nagyspinű, trifenilamin tartalmú poli(para-fenilén) kopolimer szintézisét valósítottuk meg. Vizsgáltuk a polikondenzációs reakció körülményeinek hatását a képződő polimerek szerkezetére és molekulatömegére. Tanulmányoztuk a kopolimer optikai tulajdonságait. Kék fény emisszióját tapasztaltuk. Az emissziós maximum az oldószer polaritásának hatására eltolható volt. Mono- és bifenantrolin-funkcionalizált polietilén glikolt és poliizobutilént készítettünk és vizsgáltuk vas(II)-ionnal szembeni viselkedésüket. A vas(II)-fenantrolin komplexeket tömegspektrometriás módszerrel karakterizáltuk. Vastartalmú, jól definiált ionomer jellegű hálózatokat állítottunk elő. A hálózatok jó modellként szolgálhatnak a magnetit nanopor felületi módosításához. Az apoláros szerkezetű konjugált polimerek tömegspektrometriás vizsgálatához klorid-ion kapcsolásos módszerrel kiegészített atmoszférikus nyomású fotoionizációs (APPI) módszert fejlesztettünk ki. A továbbfejlesztett módszer segítségével lehetőség nyílt különböző végcsoportú poliizobutilének végcsoportjainak, valamint bifunkciós polimer esetén a karok számának meghatározására, fragmentáció nélküli, lágyionizációs technikával. | A glycosylated polynaphthalene-phenylene type copolymer was prepared by Suzuki copolymerization. The copolymer showed blue-light emission and self-assembly in both solution and in solid phase. The formation of blue-light emitting, uniform size nanospheres could be observed. Synthesis of a potential high-spin poly(para-phenylene) copolymer containing triphenylamine was attained. The effect of the polycondensation parameters on the structure and molecular weight of the polymers formed was studied. Optical properties of the copolymer have been investigated. It showed blue-light emission. Emission maximum could be shifted by using solvent with different polarity. Mono- and biphenantroline-functionalized poly(ethylene-glycol) and poly(isobutylene) have been prepared and their behaviour was investigated in the presence of iron(II)-ions. Iron-(II)-phenantroline complexes were characterized by mass spectrometry. Well-defined, iron containing ionomer-type networks have been prepared. Networks can be act as good models for surface modification of magnetite nanopowder. Chloride-ion attachment technique by atmospheric pressure photoionization (APPI) was developed to investigate highly nonpolar polymers. The improved method gave the possibility to investigate the end groups of polyisobutylenes with different end groups and to determinate the number of the arms in case of bifunctional polymers, without fragmentation, using soft-ionization method
Biocatalytic synthesis of new copolymers from 3-hydroxybutyric acid and a carbohydrate lactone
Lipase-catalyzed reaction of 3-hydroxybutyric acid with d-glucono-d-lactone at 5:1 molar ratio and 80 °C yielded a mixture of moderate molecular weight linear and cyclic oligomers. The most efficient biocatalyst, Candida antarctica B lipase (Novozyme 435), allowed the synthesis of new oligomeric compounds with ring-opened gluconolactone units included in the oligomeric chain, without previous derivatization of the sugar, or activation of the acid monomer. The reaction medium nature had an important influence on the product composition. Although the main copolymer amount was synthesized in tert-butanol/dimethylsulfoxide medium, the highest polymerization degrees, up to 9 for the copolymer, and 10 for the 3-hydroxybutyric acid homopolymer co-product, were achieved in solventless conditions
Biocatalytic synthesis of new copolymers from 3-hydroxybutyric acid and a carbohydrate lactone
Biocatalytic Route for the Synthesis of Oligoesters of Hydroxy-Fatty acids and ϵ-Caprolactone
Lipase/esterase-catalyzed synthesis of aliphatic polyesters via polycondensation: A review
Polymers from sugars: cyclic monomer synthesis, ring-opening polymerisation, material properties and applications
The quest for sustainable polyesters - insights into the future
Polyesters from renewable resources are an expanding area with a burgeoning scientific activity, nevertheless little has been reviewed about this particular class of polymers. The present appraisal intends to contribute to fill this literature gap by reviewing recent aspects related to the most promising renewable-based polyesters. Emphasis will be placed on bio-based polyesters that, given their comparable properties, may replace polymers derived from fossil fuel feedstock, and on bio-based polyesters with completely innovative properties for novel applications. Furthermore, the sources of renewable monomers will also be reviewed, together with the most relevant eco-friendly synthetic approaches used in polycondensation reactions leading to polyesters