Combination of fumed silica with carbon black for simultaneously improving the thermal stability, flame retardancy and mechanical properties of polyethylene

• Published in: Polymer (Guilford) Vol. 55; no. 13; pp. 2998 - 3007
• Main Authors: JIANG GONG, RAN NIU, NANA TIAN, XUECHENG CHEN, XIN WEN, JIE LIU, ZHAOYAN SUN, MIJOWSKA, Ewa, TAO TANG
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier 13-06-2014
• Subjects: Applied sciences; Carbon black; Composites; Density; Dispersions; Exact sciences and technology; Forms of application and semi-finished materials; Fumed silica; Mechanical properties; Polyethylenes; Polymer industry, paints, wood; Silicon dioxide; Technology of polymers; Thermal stability; Fireproofing; Strengthening; Carbon black; Molten state; Dispersion degree; Fumed silica; Mechanical properties; Flame retardant; Dispersion reinforced material; Thermal stabilization; Experimental study; Silica; Hybrid composite; Composite material; Thermal stability; Polyethylene nanocomposite; Thermal properties; Morphology; Flammability; Olefin polymer; Mechanism of action; Linear low density ethylene polymer; Rheological properties
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2014.05.006

The combination of fumed silica (SiO2) with carbon black (CB) for improving thermal stability, flame retardancy and mechanical properties of linear low density polyethylene (LLDPE) was investigated. The temperature at the maximum weight loss rate of LLDPE was dramatically increased by 92 degree C, and the peak value of heat release rate measured by cone calorimeter was significantly reduced by 80.7%. The improved thermal stability and flame retardancy of LLDPE were partially attributed to the formation of a percolated network structure in LLDPE matrix, and partially to the accelerated oxidation crosslinking reaction of LLDPE or other radicals by CB and SiO2. More importantly, although both SiO2 and CB were used without any pre-treatment, ternary LLDPE nanocomposites showed much higher mechanical properties compared to those of neat LLDPE. This was ascribed to good dispersions of two kinds of nanoparticles and strong matrix-nanoparticle interfacial interactions with LLDPE matrix.