Thermoplastic self‐healing polymer blends for structural composites: Development of polyamide 6 and cyclic olefinic copolymer blends. Issue 16 (20th February 2023)

• Record Type: Journal Article
• Authors: Perin, D.; Dorigato, A.; Pegoretti, A.
• Is Part Of: Journal of applied polymer science. Volume 140:Issue 16(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-02-20
• Subjects: cyclic olefinic copolymer -- fracture toughness -- polyamide -- polymer blends -- self‐healing; Polymers -- Periodicals; Polymerization -- Periodicals; 668.9
• DOI: 10.1002/app.53751
• Languages: English
• ISSNs: 0021-8995

Abstract

Abstract: One of the main limitations of high‐performance composite materials is failure due to fatigue crack propagation during service. Traditional repair methods can be expensive and time‐consuming. For this reason, the research in the field of self‐healing composites has considerably increased in the past decade. At this aim, this work is focused on the production of a polyamide 6 (PA6) matrix with self‐healing properties. Cyclic olefinic copolymer (COC) was selected as a healing agent and it was melt compounded with PA6. From scanning electron microscope micrographs, it was possible to highlight the immiscibility and the lack of interfacial adhesion between the constituents. The healing efficiency of the system was evaluated by comparing the blends' fracture toughness (KIC ), both in quasi‐static and impact mode, before and after the healing process performed at 140°C by applying a pressure of 0.5 MPa. Through the addition of 30 wt% of COC, the fracture toughness of the virgin samples slightly decreased, passing from 2.3 MPa·m 1/2 of neat PA6 to 2.1 MPa·m 1/2 . However, the presence of the 30 wt% of COC homogeneously distributed within the PA6 matrix led to a healing efficiency of 11% in quasi‐static mode and 35% in impact mode. Abstract : This work aims to explore the feasibility of producing an intrinsic self‐healing polymer matrix by using cyclic olefinic copolymer (COC) as a healing agent and polyamide 6 (PA6) as a matrix. By introducing 30 wt% of COC it was possible to obtain a healing efficiency in quasi‐static mode of 11.4 ± 2.1%, while in impact mode was 34.7 ± 9.3%.