The toughening of polyamide-6 by brominated poly(isobutylene- co- p-methylstyrene): fracture and toughening mechanisms

• Published in: Polymer (Guilford) Vol. 34; no. 21; pp. 4471 - 4480
• Main Authors: Li, Dongming, Yee, A.F., Powers, K.W., Wang, H.-C., Yu, T.C.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.01.1993; Elsevier
• Subjects: Applied sciences; cavitation; Exact sciences and technology; impact fracture; Mechanical properties; Organic polymers; Physicochemistry of polymers; Properties and characterization; toughening; impact fracture; toughening; cavitation; Terpolymer; Amide 6 polymer; Isobutene polymer; Strengthening; Bromine containing copolymer; Elastomer; Rupture; Styrene(methyl) copolymer; Styrene derivative copolymer; Experimental study; Mechanism; Mixture
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/0032-3861(93)90153-2

A study on the toughening of polyamide-6 (PA-6) with a new elastomeric modifier, brominated poly(isobutylene- co- p-methylstyrene) (BrXP-50), was conducted. Morphological analyses and mechanical tests were combined to evaluate the toughening mechanisms of modified PA-6 and the fracture mechanism of unmodified PA-6. We conclude that the fracture mechanism of unmodified PA-6 in the impact test is crazing-cracking under the dilatational stress created by the plastic constraint, while that of the BrXP-50 elastomer modified PA-6 is plastic tearing limited by the ultimate tensile strain. Cavitation of BrXP-50 elastomer particles occurred in the impact test, and is proposed as a controlling step in toughening: it relieves the plastic constraint so that the cracking process is postponed and additional plastic deformation can occur, leading to higher impact toughness.