Polyester networks based upon epoxidized and maleinated natural oils
TL;DR: In this article, a new class of unsaturated polyester resins was introduced based upon maleic anhydride, epoxidized natural oils and styrene, and the resulting thermosetting polyesters were reinforced with natural fibers such as hemp and flax fibers.
Abstract: Novel families of flexible, semiflexible and rigid crosslinked polyesters were prepared from modified natural oils such as soybean, rape-seed and linseed oil. Maleinated oils were used as anhydride-functional curing agents of epoxy resins such as bisphenol-A-diglycidylether and epoxidized natural oils. A new class of unsaturated polyester resins was based upon maleic anhydride, epoxidized natural oils and styrene. The resulting thermosetting polyesters were reinforced with natural fibers such as hemp and flax fibers. The influence of molecular architectures, curing conditions and formulations on thermal, mechanical and morphological properties were investigated.
Aus modifizierten Pflanzenolen, wie Sojabohnen-, Raps- und Leinol, wurden neue Familien flexibler, semiflexibler und starrer Polyesternetzwerke hergestellt. Maleinierte Ole wurden als anhydridfunktionelle Harter von Epoxyharzen wie Bisphenol-A-diglycidylether und epoxidierter Pflanzenole eingesetzt. Eine neue Klasse ungesattigter Polyesterharze (UP) basiert auf Maleinsaureanhydrid, epoxidierten Pflanzenolen und Styrol. Die hergestellten Polyesterduromeren wurden mit naturlichen Fasern wie Flachs und Hanf verstarkt. Untersucht wurde der Einflus von molekularem Aufbau, Hartungsbedingungen und Formulierungen auf die thermischen, mechanischen und morphologischen Eigenschaften.
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TL;DR: This paper aims to provide a history of the use of glass in the construction of buildings in Montpellier and its applications in the 21st Century.
Abstract: Reḿi Auvergne,† Sylvain Caillol,† Ghislain David,*,† Bernard Boutevin,† and Jean-Pierre Pascault‡,§ †Institut Charles Gerhardt UMR CNRS 5253 Laboratoire Ingeńierie et Architecture Macromolećulaire, Ecole Nationale Supeŕieure de Chimie de Montpellier, 8 rue de l’Ecole Normale, 34296 Montpellier Cedex 05, France ‡INSA-Lyon, IMP, UMR5223, F-69621, Villeurbanne, France Universite ́ de Lyon, F-69622, Lyon, France
790 citations
TL;DR: In this article, the specific nature of vegetable oils and the effect of their structures on the structure of polyols and polyurethanes are discussed and the environmental aspects of bio-based polyureths are discussed.
Abstract: Vegetable oils are excellent but very heterogeneous renewable raw materials for polyols and polyurethanes. This review discusses the specific nature of vegetable oils and the effect of their structures on the structure of polyols and polyurethanes. One section is dedicated to polyols for rigid and flexible foams and methods of their preparation such as direct oxidation of oils, epoxidation followed by ring opening, hydroformylation, ozonolysis, and transesterification. The next section deals with preparation and structure‐property relationships in polyurethanes from different groups of polyols, different isocyanates, and different degrees of crosslinking. The final section covers the environmental aspects of bio‐based polyurethanes, i.e., thermal stability, hydrolytic stability, and some aspects of biodegradability.
777 citations
TL;DR: In this paper, a review of recent advances in the development of biobased curing agents from renewable materials is presented. But the focus is on epoxy resins and their applications in various fields, such as coatings, adhesives, castings, modeling compounds, impregnation materials, high performance composites, insulating materials, and encapsulating and packaging materials for electronic devices.
Abstract: The drive toward sustainable practices and principles across the supply chain has led to an upsurge in renewable materials. Epoxy resins are used in a wide range of applications in various fields, such as coatings, adhesives, castings, modeling compounds, impregnation materials, high-performance composites, insulating materials, and encapsulating and packaging materials for electronic devices. In order to achieve the desired properties, uncured epoxy resins must be converted to hard, infusible, thermoset networks in the presence of a variety of curing agents, also known as hardeners. This paper reviews recent advances in the development of curing agents from renewable materials. Attention is given to modified plant oils, biobased acids and anhydrides, amines and their derivatives, biobased phenols, rosin acids, and terpenes and lignin as biobased curing agents for primarily epoxy resin or biobased epoxy resin systems.
174 citations
TL;DR: In this article, the properties of materials prepared by curing epoxidized soybean oil with various cyclic acid anhydrides in the presence of tertiary amines were investigated by dynamic mechanical thermal analysis and thermogravimetry.
Abstract: Mechanical and thermal properties of materials prepared by curing epoxidized soybean oil with various cyclic acid anhydrides in the presence of tertiary amines were investigated by dynamic mechanical thermal analysis and thermogravimetry. All samples presented thermoset material characteristics that were dependent upon the type of anhydride, the anhydride/epoxy molar ratio, and epoxy group content. The thermosets obtained from anhydrides with rigid structures as such phthalic, maleic, and hexahydrophthalic showed higher glass transition temperatures (Tg) and cross-linking densities. As expected, the Tg decreased as the anhydride/epoxy ratio decreased. The influence of the degree of epoxidation of soybean oil on the mechanical properties and Tg was also investigated. It was found that the higher the epoxy group amount, the higher the Tg and hardness. Cured resins exhibited thermal stability up to 300°C, except for those prepared with dodecenyl succinic anhydride, which began to decompose at lower temperature. They presented excellent chemical resistance when immersed in 1% wt/vol NaOH and 3% wt/vol H2SO4 solutions but poor chemical resistance in the presence of organic solvents.
160 citations
Cites background from "Polyester networks based upon epoxi..."
...Tg values obtained for the systems ESO81/anhydride/amine and R = 1 (entries 1‐7) are lower than those for the usual commercial resins based on DGEBA (8,11) but close to those of polyester resins based on ESO (12, 13 )....
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TL;DR: In this article, the effects of steric factors and of the rigidity of the diester segment formed due to the extent of conversion of anhydride groups and on the network's properties were observed.
159 citations