Effects of polyether titanate coupling agent on the flame retardancy and mechanical properties of soft poly(vinyl chloride)/basic magnesium carbonate composites

Abstract

In this paper, a new polyether titanate coupling agent (Ti4000) was used to modify basic magnesium carbonate (BMC), and Ti4000 modified BMC (Ti4000‐BMC) was characterized by X‐ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and X‐ray photoelectron spectroscopy. Then, PVC composites were prepared by adding BMC or Ti4000‐BMC into soft PVC matrix via melt blending, and their flame retardancy was examined by limiting oxygen index (LOI), UL‐94 test, and cone calorimeter test. The results show that BMC can effectively improve flame resistance and suppress smoke production of pure soft PVC. As a result, the LOI is increased from 23.9% for pure soft PVC to 29.2% for Ti4000‐BMC/PVC composite with 50 phr Ti4000‐BMC (50%Ti4000‐BMC/PVC), and the composite passes the V0 rating in UL‐94 test, the peak heat release rate, total heat release, peak smoke production rate, and total smoke production are decreased from 343.10 kW/m2, 94.50 MJ/m2, 0.17 m2/s, and 27.20 m2/kg for pure soft PVC to 234.20 kW/m2, 70.20 MJ/m2, 0.02 m2/s, and 2.30 m2/kg for 50%Ti4000‐BMC/PVC composite, respectively. The analysis of char residues suggests that Ti4000‐BMC/PVC composites form the most compact char layer structure, indicating that the soft PVC composites show better char forming ability. In addition, the yield strength is increased from 4.4 MPa for pure soft PVC to 12.9 MPa for 50%Ti4000‐BMC/PVC composite, with an increase of 193.2%, and it shows good reinforcement effect on the soft PVC matrix.

Effect of the melt flow index of compatibilizer on the melt processing and properties of highly filled magnesium hydroxide/linear low density polyethylene composites

“…Figure 11 shows the heat release rate (HRR) and total heat release (THR) for LLDPE, MH/LLDPE and MH/MAPP/LLDPE composites. Some cone calorimetric parameters including fire performance index (FPI) and average mass loss rate (AMLR) are summarized in Table 6 9,49,50 …”

“…These results indicate that both MH and MAPP can effectively inhibit smoke generation of composite, and the simultaneous addition of them can produce a synergistic smoke suppression effect. The reason is that MH is capable of absorbing heat, decomposes to produce water vapor to dilute combustible gases, and forms a heat‐resistant layer of magnesium oxide, while MAPP makes the composite burn more fully (relative to MH/LLDPE) and makes it difficult to form soot particles 6,12,49 . This may also be related to the improved interfacial compatibility or adhesion between MH and LLDPE by MAPP, which helps to form a continuous char structure to prevent the diffusion of flue gas 6,13,18,23 …”

Effects of TiO2@ZnAlSn/PETMP on the properties of plasticized polyvinyl chloride composites

“…These results indicate that incorporation of TiO 2 @ZnAlSn and PETMP can prevent the spread of flame. The PSPR and TSP values are decreased from 0.1358 m 2 s À1 and 23.0 m 2 for PVC composite to 0.0547 m 2 s À1 and 10.8 m 2 for PVC/TiO 2 @ZnAlSn/1.6PETMP † composite, with a decrease [48] of 59.7% and 53.0%, respectively. Thus, incorporation of TiO 2 @ZnAlSn and PETMP can also effectively reduce smoke production.…”

Improvement of flame retardancy and thermal stability of highly loaded low density polyethylene/magnesium hydroxide composites

“…26,28 Magnesium carbonate (MC) is also an efficient, environmentally friendly flame retardant and smoke suppressant with excellent thermal stability, low cost, and non-toxicity. 29 Although carbonates are generally considered inert fillers during the combustion process, MC, which releases CO 2 and forms magnesium oxide during the thermal decomposition at a temperature of 550 C, reduces flammability by lowering the temperature of the polymeric material surface, diluting the combustible gas phase concentration, and also forming a non-combustible char layer on the polymer material that inhibits oxygen and heat transfer. 28,30 Moreover, in polymer composites with metal hydroxides as the primary fire retardant, zinc borate (ZB) is widely added as a synergist to enhance flame retardant properties.…”

“…Calcium carbonate (CaCO 3 ) has been extensively used to enhance thermal stability and stiffness for polymeric composites 26,28 . Magnesium carbonate (MC) is also an efficient, environmentally friendly flame retardant and smoke suppressant with excellent thermal stability, low cost, and non‐toxicity 29 . Although carbonates are generally considered inert fillers during the combustion process, MC, which releases CO 2 and forms magnesium oxide during the thermal decomposition at a temperature of 550°C, reduces flammability by lowering the temperature of the polymeric material surface, diluting the combustible gas phase concentration, and also forming a non‐combustible char layer on the polymer material that inhibits oxygen and heat transfer 28,30 …”