Correlating ultra‐toughening of bio‐based polyamide 410 with melt rheological and solid state relaxation dynamics by gelation rheology approach

Abstract

The sol–gel or viscous‐elastic transitions of the bio‐based polyamide 410/POE‐g‐MA (polyethylene‐co‐octene copolymer grafted with maleic anhydride) blends have been systematically discussed in the framework of melt rheology as assessed on a parallel plate rheometer set‐up in small amplitude oscillatory shear mode and solid state dynamic mechanical relaxation measurements. The viscous response dominated enhancement in elastic moduli of the blends that was characterized by the phase transitions across the composition range of 10–15 wt% of POE‐g‐MA. A direct correlation between the gel point (estimated from the cross‐over of frequency‐independent loss tangent curves) and the ultra‐toughness (maximized to an extent of ~15‐fold increase in notched Izod impact strength) could be established vis‐a‐vis its corroboration from the morphology of the impact‐failed surfaces. The extent of maleic anhydride (−MA) content induced phase interaction with polyamide 410 via the formation of a polyamide‐co‐(polyoctene‐co‐ethylene) type copolymer linkage in solid‐state and its subsequent impact on solid‐state damping was analyzed. The study establishes qualitative correlation between ultra‐toughening of polyamide 410 to that parameters based on relaxation dynamics measurements using melt rheology and solid‐state dynamic responses conforming to the principles of gelation rheology.

Fracture toughness of PA6/POE‐g‐MA/TiO2 ternary nanocomposites according to the essential work fracture method

“…This type of polyolefin facilitates fast dispersion throughout the polyamide matrix during integration and post‐melt‐mixing, which enhances resistance to crack propagation. [ 19 ] However, in the process of modifying and improving toughness, PA6, and poly(octene‐ethylene) are often immiscible and incompatible due to the polarity difference. This incompatibility leads to a phase‐separated, coarse, and unstable morphology that becomes coarser with further processing due to particle aggregation.…”

EPDM‐g‐MAH toughened bio‐based polyamide 56 to prepare thermoplastic polyamide elastomer and the performance characterization

“…The storage modulus is still at a high value. However, when it approaches the glass transition temperature, the chain segments of the polymer begin to move, the final loss modulus increases to the maximum, and the storage modulus decreases to the minimum 55 . As shown in Figure 10a, the decrease of storage modulus occurs twice at temperatures −50 and 60°C, respectively.…”

“…However, when it approaches the glass transition temperature, the chain segments of the polymer begin to move, the final loss modulus increases to the maximum, and the storage modulus decreases to the minimum. 55 As shown in Figure 10a, the decrease of storage modulus occurs twice at temperatures À50 and 60 C, respectively. The decline at À50 C is because of the addition of EPDM-g-MAH, and the decline at 60 C is owing to quasi-elastic stability softening PA56.…”

On the crystal growth kinetics of ultra‐toughened biobased polyamide 410: New insights on dynamic crystallization

“…The density, melting temperature and MFI are 0.87 g/cc, 55 C and 1.6 g/10 min, respectively. The blends were fabricated with varying elastomer concentration (in wt.%) from 0-20 wt.% at an increment of 5 wt.% successively by using a EuroLab 16 (co-rotating twin-screw extruder of thermoFisher Scientific, USA) with l/d ratio of 20. The details of the blend composition are listed in Table 1.…”

“…The quantification of the extent of interaction due to terminal groups on the transition in viscoelasticity response and thereby the necessary elasticity build-up was also addressed within the framework of physical gelation mechanism. 20 Considering the significance of crystallization kinetics as a basis for optimization, understanding and selection of appropriate polymer processing techniques, the non-isothermal crystallization kinetics study of PA 410/POE-g-MA blends with 0-20 wt.% of POE-g-MA has been systematically investigated. The experiments were undertaken in a differential scanning calorimeter (DSC) under five different cooling rates.…”