Viscosity modeling of a medium reactive unsaturated polyester resin used for liquid composite molding process

Liquid composite molding (LCM) processes are widely used to manufacture composite parts for the automotive industry. An appropriate selection of the materials and proper optimization of the manufacturing parameters are keys to produce parts with improved mechanical properties. This paper reports on a study of biobased composites reinforced with nanoclay particles. A soy-based unsaturated polyester resin was used as synthetic matrix, and glass and flax fiber fabrics were used as reinforcement. This paper aims to improve mechanical and flammability properties of reinforced composites by introducing nanoclay particles in the unsaturated polyester resin. Four different mixing techniques were investigated to improve the dispersion of nanoclay particles in the bioresin in order to obtain intercalated or exfoliated structures. An experimental study was carried out to define the adequate parameter combinations between vacuum pressure, filling time, and resin viscosity. Two manufacturing methods were investigated and compared: RTM and SCRIMP. Mechanical properties, such as flexural modulus and ultimate strength, were evaluated and compared for conventional glass fiber composites (GFC) and flax fiber biocomposites (GFBiores-C). Finally, smoke density analysis was performed to demonstrate the effects and advantages of using an environment-friendly resin combined with nanoclay particles.

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A Comparative Study of Dispersion Techniques for Nanocomposite Made with Nanoclays and an Unsaturated Polyester Resin

Journal of Nanomaterials ◽

10.1155/2011/406087 ◽

2011 ◽

Vol 2011 ◽

pp. 1-12 ◽

Cited By ~ 32

Author(s):

Farida Bensadoun ◽

Nadir Kchit ◽

Catherine Billotte ◽

François Trochu ◽

Edu Ruiz

Keyword(s):

Rheological Behavior ◽

Polyester Resin ◽

Unsaturated Polyester ◽

Unsaturated Polyester Resin ◽

Liquid Composite Molding ◽

Scanning Calorimetry ◽

Polymer Resin ◽

The Matrix ◽

Shear Mixing ◽

Mixing Method

Over the last few years, polymer/clay nanocomposites have been an area of intensive research due to their capacity to improve the properties of the polymer resin. These nanocharged polymers exhibit a complex rheological behavior due to their dispersed structure in the matrix. Thus, to gain fundamental understanding of nanocomposite dispersion, characterization of their internal structure and their rheological behavior is crucial. Such understanding is also key to determine the manufacturing conditions to produce these nanomaterials by liquid composite molding (LCM) process. This paper investigates the mix of nanoclays particles in an unsaturated polyester resin using three different dispersion techniques: manual mixing, sonication, and high shear mixing (HSM). This paper shows that the mixing method has a significant effect on the sample morphology. Rheology, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) characterization techniques were used to analyze the blends morphology and evaluate the nanoclays stacks/polymer matrix interaction. Several phenomena, such as shear thinning and premature polymer gelification, were notably observed.

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Effect of Al2O3 on the Tensile and Impact Strength of Flax/Unsaturated Polyester Composite with Emphasis on Automobile Body Applications

Advances in Materials Science and Engineering ◽

10.1155/2021/6641029 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Gebre Fenta Aynalem ◽

Belete Sirahbizu

Keyword(s):

Impact Strength ◽

Polyester Resin ◽

Natural Fiber ◽

Resin Composite ◽

Unsaturated Polyester ◽

Fiber Material ◽

Strength Properties ◽

Unsaturated Polyester Resin ◽

Molding Process ◽

The Impact

This study has endeavored to develop an Al2O3-filled natural fiber reinforced polymer composite which is intended to substitute the most widely used synthetic E-glass fiber material. To attain the desired objective of the work, 0, 5, 10, and 15 wt% Al2O3-filled chopped flax/unsaturated polyester resin composite have been developed by the conventional hand-lay-up method followed by a compression molding process. Consequently, characterization and mechanical property tests are conducted based on the ASTM standard. The results revealed that both tensile and impact strength properties of the base chopped flax/unsaturated polyester resin composite are all affected due to the inclusion and variation of the content of Al2O3 in 15 and 25 wt% fiber loading cases. It has been noticed that a 39.06% increase in the ultimate tensile strength of the composite in 25/UPR-5 composition has been gained. The effect of Al2O3 on the impact strength of the base composite has also been analyzed and a 45% increase has been observed in 15/UPR-10 composition. The findings also witnessed that the newly developed composite can be applied to make automotive parts such as mud guard and engine undercover.

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