One‐pot synthesis of polyamide 12,T–polyamide‐6 block copolymers

Abstract

Polyamide 12,T-polyamide-6 (PA-12,T-PA-6) block copolymers were synthesized by anionic polymerization of caprolactam using a PA-12,T macrocoinitiator (McI). PA-12,T McI and its precursors are soluble in molten caprolactam allowing for both the McI step-growth polymerization and anionic polymerization to be performed in one-pot. It was found that the competing reaction rates of caprolactam ring-opening polymerization and McI transamidation are both deterred by a common ion effect using CaCl 2 and soluble materials were obtained using >1 mol % CaCl 2 . Without CaCl 2 , the reaction mixture solidifies in less than 30 s and produces crosslinked materials. To understand this effect, PA-12,T McI reactions with caprolactam were performed with 1-10 mol % CaCl 2 , and polymer structures were characterized using 13 C NMR and dilute solution viscometry. These data were then correlated with unique thermal properties and swelling behavior of the block copolymers.

Poly(decamethylene terephthalamide) copolymerized with long‐chain alkyl dodecanedioic acid: Toward bio‐based polymer and improved performances

“…PA10T/1012 is newly synthesized and has not been reported, so the K and α of it cannot be found in the existing literature. However, some researchers used the K and α of PA12T to estimate the molecular weights of other polyamides or copolyamides (such as PA4T, PA6T, PA10T‐ co ‐PA12T, PA12T‐ co ‐PA6T, and PA12T‐PA6 block polymers) . Although the calculation like this is not appropriate in theory and the results might not be the real molecular weight, it still can help to find the approximate range of the molecular weights.…”

“…However, some researchers used the K and a of PA12T to estimate the molecular weights of other polyamides or copolyamides (such as PA4T, PA6T, PA10T-co-PA12T, PA12T-co-PA6T, and PA12T-PA6 block polymers). 19,37,38 Although the calculation like this is not appropriate in theory and the results might not be the real molecular weight, it still can help to find the approximate range of the molecular weights. In view of both PA10T and PA10T/1012 have the similar chemical structure and solution properties with PA12T, the M h would be calculated by Mark-Houwink equation with the values of K and a of PA12T.…”

Synthesis and characterization of copolyamides derived from novel aliphatic bio‐based diamine

“…From such modification, the semicrystalline character and melting temperature ( T m ) of the copolyamides can be maintained . Novitsky et al . synthesized a kind of polyamide 12, T‐polyamide‐6 copolymer by anionic polymerization to obtain a PA6 copolymer having a block microstructure with improved thermal properties.…”

“…From such modification, the semicrystalline character and melting temperature (T m ) of the copolyamides can be maintained. 22 Novitsky et al 23 synthesized a kind of polyamide 12, T-polyamide-6 copolymer by anionic polymerization to obtain a PA6 copolymer having a block microstructure with improved thermal properties. On the contrary, the long chain copolyamides synthesized from ε-caprolactam (CPL), aminoundecanoic acid and nylon 66 salts have low degree of crystallinity, low glass transition temperature (T g ) and low melting temperature (T m ), which are especially suitable to be used as hot-melt adhesives.…”

Preparation, characterization and copolymerization of the 12‐membered cyclic diamide 1,6‐diazacyclododecane‐2,5‐dione

“…Due to its good mechanical strength, impact resistance, rigidity, and low density, it is widely used as an engineering material. Although polyamide 6 shows outstanding thermal and mechanical properties, copolymerization of CLA with various monomers are of industrial and academic interest, because this allows tailoring of properties for specific applications …”