Structural design of flame‐retardant phosphatized unsaturated polyester resin

Abstract

To improve flame-retardant properties of unsaturated polyester resin (UPR), two phosphorus-containing vinyl monomers with different chemical structures were synthesized to replace styrene molecules and then copolymerized with UPR oligomers to prepare flame-retardant phosphatized UPRs. Curing behavior of phosphatized UPRs was investigated by DSC non-isothermal curing curves, deducing the best curing conditions. Cone calorimeter results demonstrated the obvious reduction of heat release rate and smoke production rate by comparing phosphatized UPRs with flammable UPR. TG-IR-MS coupling technique was utilized to reveal thermal degradation and pyrolytic volatiles including aromatic compounds, hydrocarbons, CO, PO 4˙, and so forth, providing more information of smoke toxicity and the gas phase flame-retardant mechanism of phosphatized UPRs. Moreover, the yield, compactness and graphitic degree of char residues of phosphatized UPRs were increased, strengthening the barrier effect to inhibit the permeation of combustion heat and the effusion of pyrolytic volatiles in the condensed phase.

Enhanced performance of a bio‐based diluent with both vinyl and epoxide groups for unsaturated polyester resin applications

“…Based on the DSC tests performed at different heating rates (Figure S7), apparent activation energy ( E a ) values of the two polymerizations were calculated by the Kissinger and the modified Ozawa methods (Figures S8 and S9), respectively, 46,47 yielding E a values of 95.4 kJ/mol (Ozawa) and 87.9 kJ/mol (Kissinger) for the first polymerization. They are in good agreement to previous reports, for example, 90.6 kJ/mol (Ozawa) and 86.6 kJ/mol (Kissinger), respectively 48 . While the E a values yielded for the second polymerization are 66.8 kJ/mol (Ozawa) and 68.1 kJ/mol (Kissinger), which are comparable to the values of epoxy/amine reactions reported previously 49 …”

“…They are in good agreement to previous reports, for example, 90.6 kJ/mol (Ozawa) and 86.6 kJ/mol (Kissinger), respectively. 48 While the E a values yielded for the second polymerization are 66.8 kJ/mol (Ozawa) and 68.1 kJ/mol (Kissinger), which are comparable to the values of epoxy/amine reactions reported previously. 49 Therefore, we proposed a mechanism of the crosslinking reactions in Scheme 3.…”

Effect of Microwave Irradiation at Different Stages of Manufacturing Unsaturated Polyester Nanocomposite

“…At the first stage, the reaction is initiated, and the inhibitor contained in the oligomer is consumed (at dT < 0, Figure 6 ), and at the second stage, the composition is directly cured (at dT > 0, Figure 6 ). Blanco and colleagues speculate that the shoulder that appears on the graph in the region of 140–150 °C is the result of homopolymerization of the polyester oligomer as a result of providing the system with sufficient energy [ 25 , 26 ].…”

Ionic liquids modified MXene as a flame retardant synergist for the unsaturated polyester resin

“…It is widely used as a base material in industries such as shipbuilding, construction and automotive. [1][2][3] However, the disadvantages of UPR, such as flammability and the generation of a large amount of smoke and toxic gases during combustion, have limited its applications. 4 To reduce its flammability, a common method is to add flame retardants.…”

“…Unsaturated polyester resin (UPR) is a thermosetting polymer with the characteristics of low cost, convenient processing and low density. It is widely used as a base material in industries such as shipbuilding, construction and automotive 1–3 . However, the disadvantages of UPR, such as flammability and the generation of a large amount of smoke and toxic gases during combustion, have limited its applications 4 .…”