A new method to prepare low melting point polyamide‐6 and study crystallization behavior of polyamide‐6/calcium chloride complex by rheological method

Abstract

A new method to prepare low melting point polyamide-6 (LPA6) by complex reaction of calcium chloride (CaCl 2 ) and polyamide-6 (PA6) in a co-rotating twin screw extruder was reported. We employed a new rheological method to study the crystallization behavior of PA6/CaCl 2 complex and the mechanism of confined crystallization of PA6. Compared with differential scanning calorimetry (DSC), this method was more capable of detecting crystalline information. What's more, it was also an effective method for studying mechanism of confined crystallization. From the results of X-ray diffraction, DSC, infrared spectroscopy, rheology, and mechanical properties, the complex reaction of CaCl 2 with the carbonyl oxygen atom in the amide group disrupted the intermolecular hydrogen bonding and confined the mobility of PA6 molecules. This could significantly reduce the crystallinity and melting temperature of PA6, and improve tensile strength and notched Izod impact strength.

Influence of the ion content of CaCl2-ionised polyamide-66 nucleator on the crystalline nucleation of poly(ethylene terephthalate) through ion–dipole interactions

“…To further verify the successful preparation of CaCl 2 -PA-66 and quantify the IC(CaCl 2 ) values of these ionenes, the Ca contents of 2.0 wt% CaCl 2 -PA-66, 5.0 wt% CaCl 2 -PA-66 and 10.0 wt% CaCl 2 -PA-66 relative to PA-66 were measured by ICP-OES. Based on the above FTIR spectra, two assumptions were made in the quantitative IC calculations: each CaCl 2 molecule is complexed with the two carbonyl O atoms from any two amide groups of PA-66; 26 and both amide groups of any participating structural repeat unit are ionised to form an ionised structural repeat unit. Hence, the IC(CaCl 2 ) values of the four samples were counted by eqn (1), and the resulting data are presented in Table 1.…”

Effects of inorganic metal ions on the mixture of single polyoxyethylene chain carboxylate surfactant and Gemini quaternary ammonium surfactant

“…24 Some studies on polyamide materials modified by Ca 2+ also revealed the complexation of amide group with Ca 2+ . [25][26][27] These findings can make surfactants containing polyoxyethylene group and amide group replace chelating agents in detergents to prevent water pollution and achieve sustainability.…”