Evaluation of the engineering performance of different bio-based aliphatic homopolyamide tubes prepared by profile extrusion

In the present study, three different commercial bio-based polyamides (bio-PAs), namely polyamide 610 (PA610), polyamide 1010 (PA1010), and polyamide 1012 (PA1012), were processed by profile extrusion with an annular die. These aliphatic homopolyamides, also known as "green nylons", are industrially produced by polycondensation reaction of diamines and dicarboxylic acids that are partially or fully obtained from naturally occurring castor oil. The profile-extruded bio-PA tubes were characterized and compared in terms of their thermal, thermomechanical, and mechanical properties and also water uptake. Resultant comparative evaluation indicated that both the methylene-to-amide (CH2/CONH) ratio and the crystallinity degree of the bio-PAs played the main role in determining the performance of the tubes. Due to significant differences in their CH2/CONH ratio, the PA610 tubes showed the highest thermal properties while the tubes made of PA1012 presented the highest flexibility and lowest water uptake. Interestingly, the fully bio-based PA1010 tubes offered the most balanced and enhanced engineering performance, which was ascribed to the high crystallinity achieved during profile extrusion. The here-developed bio-PA tubes can fulfil demanding technical requirements and these also certainly represent a sustainable answer to the rising demand for new high-performance biopolymers for engineering applications.