Exploitation of a promising flame‐retardant engineering plastics by molten composited polyketone and diethyl zinc phosphinate

Abstract

Aliphatic polyketone (POK) is a new engineering plastic owning outstanding mechanics, chemical resistance, and gas/liquid barrier properties. However, analogous to other polymers, the nature of combustion severely restricts the widespread application of POK. Herein, the diethyl zinc phosphinate (ZnPi) was compounded with three grades of POKs, which were different among each other in viscosity as low (L), medium (M), and high (H) levels, by melt mixing. It is intriguing to suggest that increasing the viscosity of POK could remarkably improve the dispersion homogeneity of ZnPi, which was beneficial to superior flame retardancy, simultaneously with comprehensive mechanical properties. For the H-POK matrix, only 10% well-dispersed ZnPi resulted in a V0 ranking with a good maintenance of its notched impact strength, whereas the load of ZnPi for reaching V0 rank increased to 14% in L-POKs and M-POKs and the mechanical performances decreased mildly. By a combination of scanning electron microscopy (SEM), Fourier-transform infrared (FTIR), thermogravimetric analysis (TGA), and cone calorimetry, it is well revealed that the flame retardancy induced by adding ZnPi could mainly ascribe to the formation of various zinc phosphate species. This work exploits a facile and feasible method for fabrication of antiflame engineering plastics, which will be promising for large-scale applicability of high-performance POK materials.

Improving Flame Retardant Properties of Aliphatic Polyketone (POK)-Based Composites

“…In general, when powder additives are added to polymer composites, it affects the mechanical values negatively. This is due to agglomeration of the flame retardant additive, poor interfacial interactions, imperfections, and voids . Izod notched impact strengths of POK and POK-based composites containing flame retardant additives are given in Figure .…”

“…When a 10 wt % OP-based flame retardant additive was added to the neat POK, the flame rating reached a V0 rating class. Formation of specific phosphorus species by means of the degradation reaction of phosphinates makes the char layer covered on the residual sample surface to inhibit further fusion and combustion . OF acted mainly through flame inhibition and phosphorus was released to the gas phase and induced the char formation in the residue .…”

“…This is due to agglomeration of the flame retardant additive, poor interfacial interactions, imperfections, and voids. 14 Izod notched impact strengths of POK and POKbased composites containing flame retardant additives are given in Figure 3. When 10%, 15%, 20%, and 25 wt % flame retardant additives were added to the POK composites, it did not exhibit a noticeable effect on the Izod notched impact strength.…”

“…Formation of specific phosphorus species by means of the degradation reaction of phosphinates makes the char layer covered on the residual sample surface to inhibit further fusion and combustion. 14 OF acted mainly through flame inhibition and phosphorus was released to the gas phase and induced the char formation in the residue. 28 While the FR ratio was increased up to 25 wt %, the V0 flame rating of POK compounds did not change for the studied thickness.…”

Preparation and characterization of polybenzoxazine foam with flame retardancy

“…[3][4][5] Nevertheless, the flame retardancy property is an important factor that must be considered in some applications such as building materials, aerospace fields, and naval vessels. [6][7][8][9] Although PU, PI, PE, and PS foams have good mechanical and thermal properties, they are easily burned. Thus, developing polymer foams with flame retardancy properties is required in some applications.…”