Bio-based thermosets: Effect of the structure of polycarboxylic acids on the thermal crosslinking of maltodextrins

The Effect of Cross-Linking with Citric Acid on the Properties of Agar/Fish Gelatin Films

“…In this regard, agar molecules form double helices at low temperatures (30-40 • C), but they exist as random coils when dissolved in water at high temperatures (above 85 • C) [33]; therefore, the temperatures (80-110 • C) employed to prepare films in this work made the agar chains more accessible when reacting with citric acid by an esterification reaction. An almost inappreciable shoulder, located at around 1740 cm −1 , can be related to the residual citric acid [34]. Such an esterification would improve the water resistance of films [35], as shown by the swelling curves in Figure 1.…”

Effect of CaO in the thermal crosslinking of maltodextrin and citric acid: A cooperative action of condensation and ionic interactions

“…The Interactions of Ca Ion with the System Based on MAL and CA IR Study. According to previous work, 8 the evolution of the polycondensation reaction between MAL and CA can be followed by IR. The C@O stretching band, assigned to the ester bond between the hydroxyl groups of MAL and the carboxyl group of CA, and the OH stretching band evolve as the esterification reaction is progressing.…”

“…The esterification reaction between carboxyl groups of CA and hydroxyl groups of MAL has been analyzed by TGA as reported in previous work. 8 In Figure 10 are compared the TGA and corresponding first derivative for the compositions in Table I. The weight loss due to the water released by the esterification reaction around 130 8C is identified 37 in all the compositions.…”

“…This makes these systems to deliver limited mechanical performance especially upon weathering conditions (temperature, humidity). The system containing maltodextrin and citric acid have been studied in previous work . It was demonstrated that the polycondensation reaction between maltodextrin and citric acid can deliver a thermoset system under processing conditions at 140 °C.…”

“…The system containing maltodextrin and citric acid have been studied in previous work. 8 It was demonstrated that the polycondensation reaction between maltodextrin and citric acid can deliver a thermoset system under processing conditions at 140 8C. However, when comparing this system with traditional petrol based systems like, for instance, phenolic resins for its application in glass fiber materials, mechanical performance of this last are still the best.…”