Moisture Adsorption and Desorption Behavior of Raw Materials for the T-RTM Process

Abstract

The use of fiber reinforced plastics (FRPs) has significant potential to reduce the weight of components. As regards the sustainability of these components, thermoplastic matrices offer more potential for recycling than thermoset ones. A possible manufacturing process for the production of thermoplastic FRPs is thermoplastic resin transfer molding (T-RTM). In this very moisture-sensitive process, ε-caprolactam in addition to an activator and catalyst polymerizes anionically to polyamide 6 (aPA6). The anionic polymerization of aPA6 is slowed down or even completely blocked by the presence of water. This study analyses the sorption behavior of the matrix, fiber, binder and core materials for the production of anionic polyamide 6 composites, which are processed in the thermoplastic RTM process. Water vapor sorption measurements are used to determine the adsorption and desorption behavior of the materials. The maximum moisture loading of the materials provides information about the water adsorption capacity of the material. This knowledge is crucial for correct handling of the materials to achieve a fast process and good properties of the final product.

Thermoplastic matrix‐based composites produced by resin transfer molding: A review

“…[7] In addition, an investigation of the moisture adsorption and desorption in the ε-CL/PA-6 reactive system (as in fibers) has already been conducted, and should be extended to other reactive thermoplastic systems. [93] Owing to extremely low viscosity of some systems, for example, ε-CL/PA-6, problems of mold sealing have arisen; nevertheless, the use of double seals can solve this problem. [7] Mechanical, thermal, and chemical recycling are the main techniques used to recycle thermoplastic composites.…”

Binders Used for the Manufacturing of Composite Materials by Liquid Composite Molding

“…It is most often recommended to choose a binder of the same nature as the infusion matrix used to impregnate the preform [ 41 , 68 , 69 , 70 ]. For example, a thermoplastic polyamide 12 powder binder is recommended for the thermoplastic resin transfer molding of ε -caprolactam, which can be anionically polymerized into PA6.…”

The effect of the titanium dioxide nanoparticles on the morphology and degradation of polyamide 6 prepared by anionic ring‐opening polymerization

“…The composite base layer and the surface layer can be produced in one cycle with this technology. [ 1–9 ]…”

“…The composite base layer and the surface layer can be produced in one cycle with this technology. [1][2][3][4][5][6][7][8][9] Cyclic lactams (amides) are most often produced by anionic ring-opening polymerization. [10][11][12][13] The process is popular, not only because it is fast, but also due to its low activation energy and minimal material requirements.…”