Preparation, analysis, and isothermal crystallization behavior of poly[1,3‐bis(aminomethyl)cyclohexamethylene oxamide]

Abstract

Poly[1,3-bis(aminomethyl)cyclohexaneoxamide] (PBAC2) was synthesized using 1,3-bis(aminomethyl)cyclohexane (BAC) and dibutyl oxalate (DO) via spray/solid-state polycondensation (SSP). The structure of the synthesized polyoxamide was confirmed by 1 H-nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy. The weight average molecular weight (M w ) of the polyoxamides prepared was 1.35 3 10 5 . The polyoxamides showed excellent thermal properties with glass transition temperature (T g ) of 150 8C, melting temperature (T m ) of 318 8C, crystallization temperature(T c ) of 253 8C, and initial degradation temperature (T d ) of 417 8C suggesting higher thermal stability than commercial polyamide 6 (T d 5 378 8C). Kinetic studies of PBAC2 predicted a two-dimensional crystal growth. X-ray diffraction powder diffraction suggested that the polymer has high crystallinity. A saturated water absorption of 2.8 wt % was recorded for the new polyoxamide, giving it a competitive edge for applications in civil aviation, reinforced plastics, and electronics industry where precise dimensional stability and high thermal resistance properties are a priority.

Novel alternating copolyoxamides with high crystallinity and heat resistance

“…The unique double hydrogen bonding endows it excellent performance, [22][23][24][25] such as high heat resistance, low water absorption, good crystallization properties together with mechanical properties. With the increasing demand for high temperature resistant polyamides in recent years, polyoxamides have aroused more and more attention in industry [26][27][28][29][30][31][32] and academia [33][34][35] and have a good marketing prospects.…”

“…Additionally, it has further been reported that the relative insolubility of most polyoxamides prevents the formation of high molecular weight polymers when using conventional solution techniques. To obtain high molecular weight polyoxamides, a two stage procedure has been reported recently, [33][34][35] where a prepolymer is prepared at low temperature from a diester of oxalic acid and a diamine followed by solid state polymerization.…”

Synthesis and characterization of poly(hexamethylene terephthalate/hexamethylene oxamide) alternating copolyamide (alt‐PA6T/62)

“…In this method, polyoxamides with η int = 1.9 were prepared. Recently, much research on polyoxamides has been reported by utilizing this two‐step polymerization method, and high‐performance polyoxamides have been successfully synthesized 24–29 …”

“…Recently, much research on polyoxamides has been reported by utilizing this two-step polymerization method, and high-performance polyoxamides have been successfully synthesized. [24][25][26][27][28][29] Comonomers are commonly utilized in polyamides to change the melt temperature and improve the processability. In this way, random copolyamides can be easily prepared.…”