Polymers molten, coating with

It is well known that alkali metal favors the polymerization of caprolactam. Hamann discovered that electrolysis of a molten solution, which contained caprolactam, isocyanate as activator and an alkali salt, yielded polyamide coated around the steel cathode (24). The polymerization took place above 120° C and the relative viscosity of the polymer increased with the reaction temperature. Yield of polymer was directly proportional to current density up to 1 mA/cm . A trace of water (up to 0.04%) retarded the polymerization. 

Solder masks (solder resists) are protective polymer coatings used on printed circuit boards (PCB s) to prevent solder bridging between conductors during soldering (1-3). The selective application of the solder mask limits the amount of conductor area in contact with the molten solder, minimizing solder usage and slowing the rate of conductor metal contamination in the solder pot. 

Samples from these films were again placed between Teflon-coated aluminum foil and were suspended in a forced convection oven at 170°C for 30 min. The molten polymer was then mechanically propelled into a bath of isopentane slurry at — 160°C as described previously (53). The isopentane was cooled with an outer jacket of liquid nitrogen. The quenched sample was removed from the isopentane and was allowed to anneal at room temperature for 20 hr prior to examination by IR spectroscopy at 78-290 K. 

In the third method, SiC powder is mixed with a polymer binder and extruded. The rod is then sintered in a carbon furnace at approximately 2300°C. To give the rod low-resistance terminations the ends are dipped into molten silicon, which is allowed to infiltrate along a predetermined length. In all cases the ends of the elements are coated with aluminum to make electrical contacts. 

Textile fabrics are finished with effective antimicrobial substances like ammonium, chlorinated diphenylethers (Triclosan), bisphenols, silver zeolites or cyclodextrines. Silver is an effective antimicrobial material and the constant release of a small amount of silver ions will kill bacteria or fungal growth. Silver particles may be added to the molten polymer or a silver coating may be applied to the fibres by a galvanic process. 

Fats and waxes, such as camauba wax, glycerol monostearate, hydrogenated ricin oU, for coating with molten polymers... 

Slot-die or extrusion coating involves the application of molten polymer resin through a slot die directly onto the surface of a nonwoven. Upon extrusion, the resin is smoothed and quenched by a cooling roll. Coating weight is controlled by slot size and extrusion rate. In a variant of this method, nonwoven fabrics are combined with an extruded film just after the die and before the roll-stack. The fabrics can be subsequently chemically bonded to give a sandwich structure. Such products are used as waterproof insales in shoes. 

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