An acrylic resin system for in‐situ pultrusion: Curing performances and rheology

Abstract

In recent years, the use of low viscosity and in‐situ polymerizable thermoplastic acrylic resins for advanced fiber reinforced composites has grown, specially to address the difficulty of fiber impregnation with high‐melt viscosity thermoplastic polymers. The present work investigated the curing kinetics, chemo‐rheology of an acrylic resin system for in‐situ pultrusion, and proposed the corresponding constitutive models. First, the curing kinetics was studied with the differential scanning calorimetry experiments. The viscosity development was obtained by a rheometer as functions of the degree of cure (DOC) and temperatures. The gelation point was acquired from the intersection point of storage and loss modulus curves through dynamic mechanical analysis test, which occurs at DOC of 0.65 determined by the cure kinetics model. Through the dynamic mechanical analysis, a four step cure hardening modulus model (modified CHILE approach) was proposed. The aforementioned models were applied in a case study to evaluate the influence of process parameters on the DOC, viscosity and physical behavior of the acrylic resin system in the pultrusion die.Highlights Material characterizations of an acrylic resin system are investigated. The cure kinetics and viscosity and elastic modulus models are proposed. A pultrusion case study is given.

Saturated transverse permeability of unidirectional rovings for pultrusion: The effect of microstructural evolution through compaction

“…Figure 6A shows the experimental results of the permeability measurements. The corresponding permeability levels of each preform were depicted separately with their best fits to Equation (6). The fitting constants for each…”

“…Process parameters such as pulling speed and die temperature can be optimized to obtain full impregnation and minimum porosity using numerical process simulations. [2][3][4] Permeability characteristics of the fiber reinforcement (in addition to the resin properties such as the viscosity and the cure kinetics 5,6 ) are key to such process simulations, which are known to be strongly related to fiber distribution.…”