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One of the most frequently used polymers in the galvanic industry as well as for Fused Filament Fabrication (FFF) is the terpolymer of acrylonitrile butadiene styrene (ABS). Its surface is etched in chromosulfuric acid to enable the chemical deposition of a metal. The use of chromium (Cr)(VI) compounds is restricted in the European Union (EU) since 2017. A new plating process is proposed here that does not rely on etching. Instead, double bonds on the ABS surface are converted to epoxides, followed by grafting of a polyethylenimine (PEI) to the surface. The so modified plastic is an ideal starting point for metal plating. Printing often leads to the formation of voids between strands and layers, which hinders subsequent wet processing. The plating process introduced here requires high demands on the water tightness of parts. The proposed printing procedure reduces the degree of penetration of water from 50% to less than 0.1% at 2 bar water pressure. The combination of the new printing procedure with the new plating process results in the deposition of industrial relevant nickel (Ni) layers. The cross‐hatch test followed by a peel test exhibits values of zero, pointing to the high adhesion of Ni to ABS. [ABSTRACT FROM AUTHOR]

Thermal induced solid phase polymer reactions between bisphenol-A-based polycarbonate (PC) and polyvinylamine (PVAm) are used to form permanent composite material. The PC-PVAm interface is characterized by infrared (IR) spectroscopy. IR spectra of synthesized reference substances which can be expected after PC-PVAm reaction are recorded and used to identify amidation product structures within the PC-PVAm interphase. Curve fit analysis is performed to isolated sub-bands. The spectral position of the carbonyl absorption band is a suitable marker for the identification of different amidation products. While the formation of urethane and cyclic Allophanate points to the formation of a co-polymer cyclic Urea indicates a PC chain scission without binding between both polymer materials. [ABSTRACT FROM AUTHOR]

The high temperature of the melt during thermoplastic processing is utilized for the surface modification of thermoplastic parts. The approach is demonstrated for polycarbonate as a reactive polymer and polystyrene as a non-reactive polymer. In case of polycarbonate, a polyamine is coupled to the polymer surface by chemical reaction. Functionalized latex beads are used for polystyrene, which are attached to the polymer surface by interdiffusion. Both surfaces adsorb selectively anionic or cationic dyes, respectively. The dyes are used as model compounds to demonstrate the potential of the surface modification approach for the fabrication of microfluidic parts. Those parts may be used for purification, accumulation, and reaction processes. [ABSTRACT FROM AUTHOR]

The surface-reactive injection moulding process is based on the reactive coupling between, e.g., a polyamine and polycarbonate (PC). The reaction takes place in a small layer and within a time of only about 1 μs before solidifying of the melt surface. Kinetic data are difficult to measure under those conditions. By model reactions in solution and in melt, first data on the reaction rate are available. Moulding experiments were made with a polyethylene imine (PEI), labelled with a naphthalimide dye. On injection of a PC melt, PEI layers of different thickness were transferred from the mould to the PC part surface. No significant residues remained on the mould surface. The thickness of the layer on PC was measured before and after solvent extraction. Conditions for best transfer and the maximum layer thickness are discussed. The electrostatic discharging behaviour of those layers on a PC part is shown. [ABSTRACT FROM AUTHOR]