Sequential curing of off-stoichiometric thiol–epoxy thermosets with a custom-tailored structure

Fernández‐Francos, Xavier; Konuray, Osman; Belmonte, Alberto; Flor, Silvia De la; Serra, Àngels; Ramis, Xavier

doi:10.1039/c6py00099a

Cited by 104 publications

(185 citation statements)

References 57 publications

Supporting

Mentioning

162

Contrasting

Unclassified

Order By: Relevance

“…Both reactions are depicted in Scheme (right‐hand side). The reaction mechanisms of nucleophile‐initiated thiol–epoxy polymerization and epoxy homopolymerization have been recently discussed in detail elsewhere . Because the kinetics of the second process are much slower than the first one, it has been possible to develop recently a new family of dual‐curable thermosetting materials that have found, so far, an application in shape‐memory devices …”

Section: Resultsmentioning

confidence: 99%

“…For this expression to be valid, there should be a controlled curing sequence and therefore good separation between processes, as is commonly observed in off‐stoichiometric thiol–epoxy systems …”

Section: Methodsmentioning

confidence: 99%

“…This curing system has manifold advantages: only one initiator is required to activate both reactions, a wide range of tertiary amine initiators are available, formulations can be safely prepared due to the slow activation of the curing process and it can be used dual‐curing applications where UV irradiation is not feasible. Intermediate materials with properties ranging from viscoelastic liquid to lightly crosslinked structures can be easily designed by means of changing the monomer feed ratio and structure . It makes sense to choose a dual‐curing formulation that does not gel in the first curing stage, so that a stable liquid‐like intermediate material is obtained, and crosslinking takes place entirely in the second curing stage in a more controlled way (see Scheme ).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Sequential heat release: an innovative approach for the control of curing profiles during composite processing based on dual‐curing systems

Romero

Fernández‐Francos

Ramis

2018

Polymer International

Self Cite

View full text Add to dashboard Cite

The sequential heat release (SHR) taking place in dual‐curing systems can facilitate thermal management and control of conversion and temperature gradients during processing of thick composite parts, hence reducing the appearance of internal stresses that compromise the quality of processed parts. This concept is demonstrated in this work by means of numerical simulation of conversion and temperature profiles during processing of an off‐stoichiometric thiol–epoxy dual‐curable system. The simulated processing scenario is the curing stage during resin transfer moulding processing (i.e. after injection or infusion), assuming one‐dimensional heat transfer across the thickness of the composite part. The kinetics of both polymerization stages of the dual‐curing system and thermophysical properties needed for the simulations have been determined using thermal analysis techniques and suitable phenomenological models. The simulations show that SHR makes it possible to reach a stable and uniform intermediate material after completion of the first polymerization process, and enables a better control of the subsequent crosslinking taking place during the second polymerization process due to the lower remaining exothermicity. A simple optimization of curing cycles for composite parts of different thickness has been performed on the basis of quality–time criteria, producing results that are very close to the Pareto‐optimal front obtained by genetic algorithm optimization procedures. © 2018 Society of Chemical Industry

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Sequential heat release: an innovative approach for the control of curing profiles during composite processing based on dual‐curing systems

Romero

Fernández‐Francos

Ramis

2018

Polymer International

Self Cite

View full text Add to dashboard Cite

show abstract

“…Epoxy resins are commonly cured by active hydrogen-containing compounds such as phenol novolac, bisphenol A novolac, dicyandiamide, and diamine [4][5][6][7][8][9][10][11][12][13]. However, the reaction product from active hydrogen and epoxy lead to a secondary alcohol.…”

Section: Introductionmentioning

confidence: 99%

High-Tg, Low-Dielectric Epoxy Thermosets Derived from Methacrylate-Containing Polyimides

et al. 2017

View full text Add to dashboard Cite

Three methacrylate-containing polyimides (Px-MMA; x = 1-3) were prepared from the esterification of hydroxyl-containing polyimides (Px-OH; x = 1-3) with methacrylic anhydride. Px-MMA exhibits active ester linkages (Ph-O-C(=O)-) that can react with epoxy in the presence of 4-dimethylaminopyridine (DMAP), so Px-MMA acted as a curing agent for a dicyclopentadiene-phenol epoxy (HP7200) to prepare epoxy thermosets (Px-MMA/HP7200; x = 1-3) thermosets. For property comparisons, P1-OH/HP7200 thermosets were also prepared. The reaction between active ester and epoxy results in an ester linkage, which is less polar than secondary alcohol resulting from the reaction between phenolic OH and epoxy, so P1-MMA/HP7200 are more hydrophobic and exhibit better dielectric properties than P1-OH/HP7200. The double bond of methacrylate can cure at higher temperatures, leading to epoxy thermosets with a high-T g and moderate-to-low dielectric properties.

show abstract

“…Thiol-epoxy click reaction has been utilized in several applications [20] such as polymer synthesis [21,22] and functionalization [23][24][25], hydrogel [26] and high-performance coatings [27][28][29], etc. [30,31].…”

Section: Introductionmentioning

confidence: 99%

Polyhedral oligomeric silsesquioxane-based hybrid networks obtained via thiol-epoxy click chemistry

et al. 2017

View full text Add to dashboard Cite

Sequential curing of off-stoichiometric thiol–epoxy thermosets with a custom-tailored structure

Abstract: A novel sequential dual-curable thermosetting system with a custom-tailorable structure based on a click thiol–epoxy reaction and excess epoxy is presented.

Cited by 104 publications

References 57 publications

Sequential heat release: an innovative approach for the control of curing profiles during composite processing based on dual‐curing systems

Sequential heat release: an innovative approach for the control of curing profiles during composite processing based on dual‐curing systems

High-Tg, Low-Dielectric Epoxy Thermosets Derived from Methacrylate-Containing Polyimides

Polyhedral oligomeric silsesquioxane-based hybrid networks obtained via thiol-epoxy click chemistry

Contact Info

Product

Resources

About