Bamboo fibers composites based on styrene-free soybean-oil thermosets using methacrylates as reactive diluents

Bio‐Based Polymers Obtained from Modified Fatty Acids and Soybean Oil with Tailorable Physical and Mechanical Performance

“…Then, the random scission of the bio‐based polymers takes place and results in two peaks appearing in the derivative thermal gravimetric (dTGA) curves: the first one is attributed to the breakdown of ester bonds in MLA, MOA, and AESO segments and the second is tied to the complete degradation of bio‐based copolymers. [ 4 ] On the other hand, there are small differences regarding thermal degradation resistance: the AESO homopolymer is more thermally stable than any of the copolymers and among the copolymers those obtained from MLA are less resistant than those obtained from MOA, as indicated previously. In this sense, it is known that the thermal stability and the mechanism of thermal degradation of polymers depend primarily on their molecular structure.…”

“…Besides, the amount of branches (dangling fatty acid chains) for a fixed mass composition would be higher when using MLA as precursor in the copolymer formulation. Evidently, in this particular case, these effects influence the thermal stability of the copolymers to a greater extent than the crosslinking degree (i.e., for polymers of similar structures as higher is the crosslinking degree higher is the thermal stability [ 4 ] ) or the extra double bond (i.e., thermally weak point) that does not participate in the free radical polymerization contained in the MOA precursor, although in this case it is more likely that this unsaturation becomes saturated during the early stages of the thermal degradation test. In the last degradation step (above 600 °C), the bio‐based materials are transformed into ashes and char residues.…”

“…[ 2,3 ] Among biorenewable raw materials, several vegetable oils have been proposed since they contain several reactive sites that can be chemically transformed to produce polymer precursors that mainly lead to the obtaining of thermoset polymers. [ 4–6 ] Traditionally, unsaturated vegetable oils are used in the coating industry, mainly as drying oils or to produce alkyd resins. [ 7 ] Today, technological progress in oleochemistry has expanded the range of applications of vegetable oils and demonstrated their vast potential to improve sustainable development.…”

“…Acrylated epoxidized soybean oil (AESO) is a commercially available vegetable oil‐based resin with high potential for replacing traditional petroleum‐based materials and thus alleviate energy and environment problems. [ 4,8 ] However, AESO has high viscosity and leads to copolymers with low crosslinking density when homopolymerized, making it difficult to expand its applications. To solve these problems, low‐viscosity reactive diluents, usually derived from the petrochemical industry such as styrene, divinylbenzene, acrylates, and methacrylates, are frequently added [ 6,9–12 ] to improve the fluidity of the initial (unreacted) mixture resulting in a copolymerization reaction.…”

Thermosets resins prepared from soybean oil and lignin derivatives with high biocontent, superior thermal properties, and biodegradability

“…The storage modulus ( E ′ ) and loss factor (tan δ) versus temperature curves of cured thermosets are showed in Figure (a,b). The E ′ indicates the energy stored during cyclic deformation, and tan δ shows the damping behavior under vibrating conditions . The peak of the tan δ was used to determine T g for the thermosets, and the crosslinking density ( v e ) was further estimated from the following equation based on the rubbery elastic theory: where E ′ is the storage modulus after T g in the rubbery plateau region ( E ′ at a temperature of T g + 40 K at which all crosslinked networks were in a rubbery state was chosen for this study), R is the gas constant and T is the absolute temperature.…”