High Tg catalyst-free self-healing vitrimer derived from turpentine and its application in glass fiber reinforced composites

Abstract

Conventional glass fiber reinforced composites (GFRCs) are usually difficult to degrade and the matrix usually exhibit low T_g. To address this dilemma, a degradable catalyst-free self-healing vitrimer matrix with a high T_g was fabricated using turpentine-derived terpene maleic acid (TMA) as a curing agent and epoxidized menthane diamine (EMDA) with a tertiary amine structure as an epoxy resin. Due to the introduction of a rigid terpene ring skeleton of turpentine, EMDA−TMA vitrimer exhibits a T_g of up to 201.8°C. Due to the tertiary amine groups in the EMDA−TMA, the vitrimer can achieve self-healing and recycling properties by dynamic transesterification reaction without the addition of catalysts. More importantly, the EMDA−TMA−GF composite prepared using EMDA−TMA vitrimer as a matrix also shows a high T_g (223.6°C), and excellent mechanical properties. In addition, under the synergistic action of potassium hydroxide (KOH) and ethanolamine (EA), the EMDA−TMA−GF composite can be rapidly degraded by a KOH/EA solution to realize non-destructive recovery of glass fibers.