Bio-Implants Derived from Biocompatible and Biodegradable Biopolymeric Materials
P. Mereena Luke, K. R. Dhanya, Didier Rouxel, Nandakumar Kalarikkal, Sabu Thomas in Advanced Studies in Experimental and Clinical Medicine, 2021
Microcapsules were added to PLA to form a composite material with self-healing property. The microcapsules are filled with additives for healing. It can function when cracked and releasing the self-healing additives to fractured areas. This can also function as nucleating agents to improve the PLA composite’s temperature resistance. Self-healing microcapsules can be created by encapsulating the dicyclopentadiene and Grubbs catalyst. It is then released into damage volumes and undergoing polymerization by the chemical reaction of the catalyst. This technique helps in the recovery of the polymer composite’s toughness towards facture.
Microencapsulation of reactive isocyanates for application in self-healing materials: a review
Published in Journal of Microencapsulation, 2021
Amanda N. B. Santos, Demetrio J. dos Santos, Danilo J. Carastan
Since the pioneering work of White et al. (2001), microencapsulation of curing agents has been explored to autonomically heal a polymer matrix. The healing system was composed by a microencapsulated curing agent and a catalyst, both dispersed separately within an epoxy matrix with living sites. In this system, the cracks worked as a trigger, breaking the microcapsules and releasing the curing agent by capillary action into the damaged plane. The curing agent then reacted with the living sites in the matrix, assisted by the catalyst, allowing the damage to be healed as crack faces are bonded together without any manual intervention, as schematised in Figure 1. The self-healing system proposed consisted of an epoxy matrix, urea-formaldehyde microcapsules containing dicyclopentadiene (DCPD) and solid phase Grubbs’ catalyst. After microcapsule rupture, the crosslinking reaction occurs through ring-opening metathesis polymerisation (ROMP) between epoxy and DCPD, chemically triggered by the Grubbs’ catalyst. The occurrence of this reaction in the self-healing system was confirmed by scanning electron microscopy and infra-red spectroscopy.
Influence of synthesis parameters on properties and characteristics of poly (urea-formaldehyde) microcapsules for self-healing applications
Published in Journal of Microencapsulation, 2019
Ana Cláudia Medeiros de Carvalho, Evans Paiva da Costa Ferreira, Mauricio Bomio, José Daniel Diniz Melo, Ana Paula Cysne Barbosa, Maria Carolina Burgos Costa
Endo-dicyclopentadiene (DCPD) (Sigma-Aldrich, St. Louis, MO, USA) with a melting point of 33 °C was used as self-healing agent (core material). Grubbs catalyst first generation (Sigma-Aldrich, St. Louis, MO, USA, P.A. 97%) was used as catalyst of the self-healing system. Epoxy monomer Ar260 (Barracuda) and hardener AH260 (Barracuda) were used as epoxy matrix.
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