Synthesis and properties of neat, hybrid, and copolymeric polyamide 12 microparticles and composites on their basis

Abstract

Neat and hybrid polyamide 12 (PA12) based powders are important raw materials for additive manufacturing. This study describes a facile method for the synthesis of pure, hybrid and copolymeric microparticulate materials based on one‐pot activated anionic ring‐opening polymerization (AAROP) of laurolactam in solution. The results reveal the possibility to obtain in good yields, for reaction times of 2 h and temperatures of up to 110°C neat and hybrid PA12 microparticles (MP) carrying metal or carbon fillers. Copolymeric PA12/PA6 MP can also be successfully prepared. All MP materials are analyzed by spectral, microscopy, thermal, and synchrotron X‐ray scattering methods in order to clarify their morphology, chemical and crystalline structure, melting and degradation behavior. The melting temperature of the PA12 MP is lower than of the commercial PA12, the presence of metal particles or copolymerization with PA6 additionally decrease it well below 170°C. The composites prepared by compression molding of PA12 MP display elastic modulus of up to 1.49 GPa, the stresses at yield and break reaching 50 and 69 MPa, respectively. It is concluded that the neat, hybrid, and copolymeric pulverulent materials obtained via microencapsulation by AAROP in solution may be useful in additive manufacturing processing.

Single inhalation exposure to polyamide micro and nanoplastic particles impairs vascular dilation without generating pulmonary inflammation in virgin female Sprague Dawley rats

“…As indicated above, the polyamide powder used in this study served as a representative MNP that is not known to be generated with bisphenol analogs or phthalates [ 53 – 55 ] and has no reported endocrine disrupting properties. However, polyamide has a high affinity of estrogenic compounds [ 80 – 82 ] which may act as endocrine disruptors in biological settings and explain the reduction in 17β-estradiol reported in these studies.…”

“…The purpose of this study was to characterize MNP aerosol toxicity in a whole-body rodent inhalation exposure model utilizing a novel MNP. Polyamide served as a representative plastic test material that is not produced with bisphenol analogs or phthalates [ 53 – 55 ] and has no known endocrine disrupting properties. We observed robust cardiovascular alterations and systemic inflammatory and endocrine responses following polyamide exposure of female rats during estrus.…”

Newly developed biocarbon to increase electrical conductivity in sustainable polyamide 12 composites

“…The exceptional properties of Polyamide 12 have attributed to its wide use in the plastic industry and the automotive industry. Vasileva Dencheva, Braz, and Denchev [ 27 ] developed PA 12 based neat, hybrid and co‐polymeric micro‐particulate based materials for additive manufacturing by combining different monomers for PA 12 and PA 6, respectively. They used different fillers namely Aluminum, Iron and Carbon Black at 2 wt% to develop composites.…”

“…They used different fillers namely Aluminum, Iron and Carbon Black at 2 wt% to develop composites. [ 27 ] Characterization of the composites fabricated form these micro‐particulate materials showed promising mechanical properties, and a drop in melting point compared to commercial PA 12 showing potential of applicability in additive manufacturing. Similarly Dul, Fambri, and Pegoretti [ 28 ] developed 3‐D printed short carbon fiber filled polyamide composites.…”

High-Resolution Micro-object Separation by Rotating Magnetic Chromatography

“…Microparticle and cell separation can be considered critical steps in many applications such as in biological analyses, food production, chemical processing, medical diagnostics, electronic waste, wastewater treatment, and many other fields . Different forces and interactions have been used to separate microparticles: gravitational, magnetic, inertial, size exclusion, field-flow, acoustic, electronic, optical, and so on.…”