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Enzyme catalyzed synthesis of renewable polyamides was investigated using Candida antarctica lipase B. A fatty acid-derived AB-type functional monomer, having one amine and one methyl ester functionality, was homopolymerized at 80 and 140 °C. Additionally, the organobase 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) was used as a catalyst. The results from the two catalysts were comparable. However, the amount of lipase added was 1.2 × 103 times lower, showing that the lipase was a more efficient catalyst for this system as compared to TBD. Moreover, the AB-type monomer was copolymerized with 1,12-diaminododecane to synthesize oligoamides of two different lengths., QC 20191205

A method for selectively reacting one, out of two identical carboxylic esters in a symmetric diester has been developed. An esterase from Mycobacterium smegmatis (MsAcT) has a restricted active site resulting in a narrow acyl donor specificity. This constraint was used to develop a selective synthesis route from divinyl adipate (a symmetric diester) towards mixed vinyl adipate esters. To find a suitable catalyst, the wild type (wt) MsAcT and two MsAcT variants: a single point mutant (L12A) and a double point mutant (T93A/F154A), were immobilized and studied under solvent-free conditions. Out of the tested catalysts, MsAcT L12A was the most selective for mono-transesterification of divinyl adipate. When divinyl adipate was reacted with 1.5 equivalents of a hydroxyl vinyl ether full conversion of DVA was observed yielding over 95% mixed diester. Furthermore, the limitations for longer dicarboxylic esters were studied, showing that MsAcT T93A/F154A tolerated up to at least dimethyl sebacate., QC 20190903

Increased environmental awareness has led to a demand for sustainable, bio-based materials. Consequently, the development of new benign synthesis pathways utilizing a minimum of reaction steps and available bio-based building blocks is needed. In the present study, vinyl ether alcohols and functional carboxylic acids were used to synthesize bifunctional vinyl ether esters using the immobilized enzyme Candida antarctica lipase B as a catalyst. Vinyl ethers are attractive alternatives to (meth)acrylates due to low allergenic hazards, low toxicity, and fast polymerization; however, difficult synthesis limits the monomer availability. The synthesis was performed in one-pot and the described method was successful within a broad temperature range (22-90 degrees C) and in various organic solvents as well as in the bulk. The synthesis of different vinyl ether esters reached high conversions (above 90%) after less than 1 h and products were purified by removing the enzyme by filtration using only small amounts of acetone. This approach is a straightforward route to reach monomers with multiple types of functionalities that can be used as different photo-curable thermoset resins. In this work, this was demonstrated by polymerizing the monomers with cationic and radical UV-polymerization. By changing the functional carboxylic acids, the architecture of the final polymer can be tailored, herein demonstrated by two examples. In the developed versatile method, carboxylic acids can be used directly as acyl donors, constituting a more sustainable alternative to the carboxylic acid derivatives used today., QC 20180802

There is a demand for new sustainable polymeric materials. Vinyl ethers are, in this context, attractive oligomers since they polymerize fast, are non-toxic, and can be polymerized under ambient conditions. The availability of vinyl ether oligomers is, however, currently limited due to difficulties in synthesizing them without using tedious synthesis routes. This work presents the synthesis of a series of vinyl ether ester oligomers using enzyme catalysis under solvent-free conditions and the subsequent photoinduced cationic polymerization to form polymer thermosets with T(g)s ranging from -10 to 100 degrees C. The whole process is very efficient as the synthesis takes less than 1 h with no need for purification and the crosslinking is complete within 2 min., QC 20190107

Chemo-enzymatic methods are powerful tools for the synthesis of novel materials. By combining the flexibility of chemical synthesis and the high selectivity of enzymes, a variety of functional materials can be achieved. In the present study, a series of α,ω-thiol telechelic oligoesters with varying amount of internal alkenes are prepared using selective lipase catalysis and are subsequently cross-linked by thiol-ene chemistry yielding alkene functional networks. Due to the reactivity of thiols and alkenes almost all present thiol-ene systems consist of two components. This work demonstrates that selective lipase catalysis in combination with renewable monomers with internal alkenes is a promising system for achieving one-component thiol-alkene functional resins with good storage stability and a high degree of thiol end-groups. The developed chemo-enzymatic route yields polymer networks with tailored amount of alkene functionalities in the final thermoset, which facilitate further postmodification., QC 20160520

Polyamides are an important and versatile family of plastics commonly used both as construction plastics and fibers. The global consumption of polyamides has grown quickly, from 800 000 tons per year in 1990 to 2 500 000 tons per year in 2011. Polyamides are highly crystalline and consequently have high melting points. This makes the synthesis of polyamides a highly energy consuming process.The objective of this thesis is to find a synthesis route for polyamides using an enzymatic catalyst. To be able to use enzymes the melting point of the synthesized polyamide needs to be lowered, otherwise the oligomers will solidify before growing to long chains. Since the high melting point is a consequence of the crystallinity the project has applied two routes to lower the crystallinity. The first route, route 1, by using long, branched monomers, and the second route, route 2, by using monomers with an unsaturation in the repeating unit. There are, to my knowledge, only a limited number of studies on polymerization of polyamides using enzymes.Experiments in this report were done at a small laboratory scale. The enzyme used was Candida antarctica lipase B (CALB). The monomers used in route 1, were produced by addition of thiols with different end groups to the internal double bond of methyl oleate. The reactions worked yielding functional monomers used for polyamide synthesis. When cysteamine, coupled to methyl oleate was polymerized the reaction was fast and the limiting factor was viscosity. The degree of polymerization, DP, for the polymerization was 8. Monomers from methyl-3-mercapto propionate and methyl oleate were co-polymerized with diamines of varying lengths. When 1,6-diaminohexane was used solubility problems arose. But the use of the longer diamine, 1,12-diaminedodecane, generated a homogenous system with a conversion of 80% of the monomer from methyl-3-mercapto propionate and methyl oleate and oligomers with a DP of 3. Methanol and chloroform were used as solvents

Enzyme catalyzed synthesis towards renewable polyamides was investigated using Candida antarctica lipase B. A fatty acid-derived AB-type functional monomer, having one amine and one methyl ester functionality was homopolymerized at 80 and 140°C. Additionally, the organobase 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) was used as catalyst. The results from the two catalysts were comparable. However, the amount of lipase added was 1200 times lower showing that the lipase was a more efficient catalyst for this system as compared to TBD. Moreover, the AB type monomer was copolymerized with 1,12-diaminododecan to synthesize oligoamides of two different lengths., QCR 20190903