Anionically prepared poly(ε-caprolactam-co-ε-caprolactone) and poly(ε-caprolactam-co-δ-valerolactone) copolymers: Thermal and mechanical properties

Flexible Composite Hydrogels Based on Polybenzoxazine for Supercapacitor Applications

Polybenzoxazines (Pbzs) are advanced forms of phenolic resins that possess many attractive properties, including thermal-induced self-curing polymerization, void-free polymeric products and absence of by-product formation. They also possess high Tg (glass transition temperature) and thermal stability. But the produced materials are brittle in nature. In this paper, we present our attempt to decrease the brittleness of Pbz by blending it with polyvinylalcohol (PVA). Benzoxazine monomer (Eu-Ed-Bzo) was synthesized by following a simple Mannich condensation reaction. The formation of a benzoxazine ring was confirmed by FT-IR and NMR spectroscopic analyses. The synthesized benzoxazine monomer was blended with PVA in order to produce composite films, PVA/Pbz, by varying the amount of benzoxazine monomer (1, 3 and 5 wt. % of PVA). The property of the composite films was studied using various characterization techniques, including DSC, TGA, water contact angle analysis (WCA) and SEM. WCA analysis proved that the hydrophobic nature of Pbz (value) was transformed to hydrophilic (WCA of PVA/Pbz5 is 35.5°). These composite films could play the same role as flexible electrolytes in supercapacitor applications. For this purpose, the composite films were immersed in a 1 M KOH solution for 12 h in order to analyze their swelling properties. Moreover, by using this swelled gel, a symmetric supercapacitor, AC//PVA/Pbz5//AC, was constructed, exhibiting a specific capacitance of 170 F g-1.

Copolymers of ε-caprolactone and ε-caprolactam via polyesterification: towards sequence-controlled poly(ester amide)s

Alternating copolymer of ε-caprolactone and ε-caprolactam is synthesized through polyesterification. This efficient and straightforward strategy holds promising future for the synthesis of sequence-controlled poly(ester amide)s.

Synthesis of Low Melting Temperature Aliphatic-Aromatic Copolyamides Derived from Novel Bio-Based Semi Aromatic Monomer

This work investigated the synthesis of a novel low melting temperature polyamide 6 (PA6) copolyamide (PA6-BABT/SA) with different aliphatic/aromatic units weight content using a melt poly-condensation process. The bio-based aromatic N¹,N⁴-bis(4-aminobutyl) terephthalamide diamine (BABT) and long-chain aromatic polyamide salt (BABT/SA, salt of BABT, and sebacic acid), components used for the synthesis of copolyamides, were obtained from bio-based monomers. For the first time, the pertinent BABT/SA aromatic polyamide salt was isolated as a white solid and completely characterized. By varying the weight ratio of BABT/SA salt, a series of copolyamides with different molecular weights and physical properties were prepared. The aromatic BABT/SA salt disrupted crystallization of the final copolyamides and lowered the onset of melting. The Fourier transform infrared spectroscopy and X-ray diffraction results indicated a steady decrease in the degrees of crystallinity with increasing BABT/SA salt segment ratio. Furthermore, compared to neat PA6, the obtained PA6-BABT/SA copolymers possessed a similar thermal stability and high transparency, but lower glass transition temperature around human body temperature. The PA6-BABT/SA copolymers with number-average molecular weight ≥30,000 Da presented good mechanical properties, specifically showing excellent tensile strength and elongation at break up to 105.2 MPa and 218.3%, respectively.