scholarly journals Thermal Hazard Characteristics of Unsaturated Polyester Resin Mixed with Hardeners

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 522
Author(s):  
Kewei Ren ◽  
Yunting Tsai
Keyword(s):  
Polyester Resin ◽  
Unsaturated Polyester ◽  
Exothermic Reaction ◽  
Thermal Runaway ◽  
Unsaturated Polyester Resin ◽  
Runaway Reaction ◽  
Scanning Calorimetry ◽  
Thermal Hazards ◽  
Thermogravimetric Analyzer ◽  
Curing Reaction

Unsaturated polyester resin (UP) is a critical polymer material in applications of many fields, such as the chemical industry, military, and architecture. For improving the mechanical properties, some hardeners, such as methyl ethyl ketone peroxide (MEKPO) or tert-butyl peroxy-2-ethylhexanoate (TBPO), can trigger the curing reaction in UP polymerization, which causes that UP changes the structure from monomer to polymer. However, polymerization is a strong exothermic reaction, which can increase the risk of thermal runaway reaction in UP. Therefore, the mechanisms and characteristics in the thermal runaway reaction of UP mixed with hardeners should be studied for preventing and controlling UP explosion. The thermal hazards of UP mixed with hardeners were determined by thermogravimetric analyzer (TGA) and differential scanning calorimetry (DSC) analysis. According to the results, UP mixed with MEKPO exhibited a more violent mass loss and exothermic reaction than UP mixed with TBPO. Furthermore, the thermal runaway reactions of UP mixed with MEKPO or TBPO with different mixing proportions of 1:1, 3:1, and 5:1 were determined. Irrespective of MEKPO or TBPO, the mixing proportions of 3:1 exhibited a high onset temperature and low enthalpy of curing reaction (ΔHexo). This demonstrated that this proportion was safer during UP polymerization. The results of this study can provide useful information for preventing UP explosion and developing polymerization technology.

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

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
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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