Polyamide 6/silica hybrid materials by a coupled polymerization reaction

Abstract

Polyamide 6/SiO2 hybrid materials were produced by a coupled polymerization reaction of three monomeric components namely 1,1',1'',1'''-silanetetrayltetrakis-(azepan-2-one) (Si(ε-CL)4), 6-aminocaproic acid (ε-ACA) and ε-caprolactam (ε-CL) within one process. Si(ε-CL)4 together with ε-ACA has been found suitable as precursor monomer for the silica and PA6 component. The accurate adjusting of the molar ratio of both components, as well as the combination of the overall process for producing the polyamide 6/SiO2 hybrid material with the hydrolytic ring opening polymerization of ε-caprolactam is of great importance to achieve homogeneous products with a low extractable content. Water in comparison to ε-ACA has been found unsuitable as oxygen source to produce uniformly distributed silica. The procedure was carried out in a commercial laboratory autoclave at 8 bar initial pressure. The molecular structure and morphology of the hybrid materials have been investigated by solid state 29 Si and 13 C NMR spectroscopy, DSC, FTIR spectroscopy and electron microscopic measurements.

Lactamomethylsilanes – Synthesis, Structures, and Reactivity towards CO2 and Phenylisocyanate

“…13 C NMR : δ = 183.9 (C=O), 46.1 (C ε ), 38.4 (C α ), 30.4 (C δ ), 29.7 (C γ ), 23.7 (C β ) ppm. 29 Si NMR : δ = –43.5 ppm (–43.5 ppm ). RAMAN : ν̃ = 2998 (w), 2936 (vs), 2857 (m), 2693 (vw), 1621 (vw), 1443 (w), 1331 (vw), 1289 (vw), 1231 (vw), 1087 (vw), 1027 (vw), 844 (vw), 766 (vw), 718 (vw), 620 (vw), 535 (vw), 427 (vw), 390 (vw), 359 (vw), 176 (vw), 134 (w), 86 (vw) cm –1 .…”

“…With strong nucleopilic bases, such as lithium organyls, imines can be synthesized starting with silylated lactams , . The silylation of ε‐caprolactam and afterwards the polymerization leads to new inorganic‐organic hybrid materials …”

Design of nanostructured hybrid materials: twin polymerization of urethane-based twin prepolymers

“…types of so-called twin monomers (TMs) are suitable for the TP. [16][17][18][19][20][21][22][23][24] Depending on their molecular structure, two of these monomers can be polymerized simultaneously to generate ternary organic-inorganic HMs (see Scheme 1b). 17,25,26 Polyurethanes (PUs) are outstanding materials due to their versatility and ability to generate tailor-made properties.…”

Ternary composites by an in situ hydrolytic polymerization process

“…In a previous work we introduced a method for the one-pot synthesis of polyamide 6 (PA6)/silica composite materials by a coupled polymerization reaction of ε-caprolactam (ε-CL), ε-aminocaproic acid (ε-ACA), and 1,1′,1′′,1′′′-silane-tetrayltetrakis-(azepan-2-one) (Si(ε-CL) 4 , 1). 26 The silicon monomer serves as precursor for PA6 as well as SiO 2 . The water, which is necessary for the hydrolysis of 1 and the formation of the organic and inorganic polymers, is delivered by the condensation of ε-ACA.…”

“…In this strategy, the coupling of the polymerization reactions leads to the formation of nanometer sized silica particles embedded in a PA6 matrix. 26 …”