Strain-Induced Form Transition and Crystallization Behavior of the Transparent Polyamide

Abstract

A transparent polyamide, poly(4,4′-aminocyclohexyl methylene dodecanedicarboxylamide) (PAPACM12), was studied and characterized by in situ wide-angle X-ray diffraction (WAXD) to establish the relationship between its crystallization behavior, crystalline form transition under external fields, and macroscopic properties. During the heating process, cold crystallization occurred and increased, and there was no form transition below the melting point. During the isothermal process, PAPACM12 exhibited the same crystalline structure as that during the heating process. The crystalline structure of PAPACM12 was attributed to α-form crystal, which is the stable form, according to the WAXD diffraction peaks of the conventional AABB-type polyamides. During stretching deformation, the crystal transition from α-form to γ-form and strain-induced crystallization were observed to contribute to the PAPACM12 with higher breaking strength and elongation. This study firstly determine the crystalline structure of transparent polyamides, and then the controlled strain-induced crystallization and transformation are demonstrated to be effective preparation methods for polyamides with high properties.

Effect of addition of fillers (MoS2 and PFA) on the tribological and mechanical properties of biobased semi‐aromatic polyamide (PA10T)

“…The influence of different proportions of fillers (MoS 2 and PFA) on the mechanical properties of PA10T‐FM composites was evaluated through tensile, bending, and impact measurements 45 . The findings from the tensile testing are presented in Figure 10, and the mechanical performance parameters, including tensile strength, breaking elongation, bending strength, bending modulus, and Izod impact strength, are summarized in Table 4.…”

“…The influence of different proportions of fillers (MoS 2 and PFA) on the mechanical properties of PA10T-FM composites was evaluated through tensile, bending, and impact measurements. 45 The findings from the tensile testing are presented in Figure 10, and the mechanical performance parameters, including tensile strength, breaking elongation, bending strength, bending modulus, and Izod impact strength, are summarized in Table 4. It can be observed that as the fillers content increased, the tensile strength and Izod impact strength of PA10T-FM composites exhibit a gradual improvement, while the breaking elongation shows a slight decrease.…”

Supercritical foaming of novel poly(ether‐b‐amide) elastomer and compression property characterization

“…These peaks can be associated respectively with the (100) and (010/110) lattices in the α-crystalline phase of PA1012. 32 It should be noted that all WAXD curves exhibit a sudden decline at 14.8 and 20.6 , respectively, where the signal intensity is zero. This unavoidable phenomenon is attributed to the multiple detectors assembling.…”

The Structural Evolution and Mechanical Properties of Semi-Aromatic Polyamide 12T after Stretching

“…To date, several approaches have been proposed for improving mechanical properties of polymers, such as blending with reinforcing fillers and regulating intrinsic crystal structures [16][17][18][19][20][21]. Among them, regulating intrinsic crystal structures of polymers is a great method for improving mechanical properties due to the low cost and regardless of interfacial compatibility between polymer and filler [16,[22][23][24].…”