Mechanical, Morphological and Thermal Properties of Rigid Polyurethane Foam: Effect of the Fillers

Abstract

Rigid polyurethane foam (PUF) having different fillers such as precipitated silica (SiO2), precipitated calcium carbonate (CaCO3) and glass powder (GP) were prepared by blowing with distilled water. The effect of filler loading on different properties of PUF was studied. In this investigation, the filler content was varied from 5 to 50 parts per hundred of polyol (phr) by weight. The properties such as density, mechanical, morphological, water absorption, thermal conductivity and thermal properties of the filled PUF were compared with the neat PUF. The density of silica filled PUF decreases with an increase in the filler loading. In case of calcium carbonate and glass powder the density initially decreases with filler loading, but after a certain concentration of fillers there is an increase in density with filler content. The mechanical properties such as compressive stress at 10% strain, compressive modulus and hardness of the filled PUF decrease in comparison with the neat PUF, due to the reaction between isocyanate and surface functional group present in filler. In all cases, the water absorption of the PUF increases with the increase in filler loading, due to the decrease in the closed cell content. The thermal conductivity analysis of PUF shows that the insulation properties decrease with the increase in silica as well as CaCO3 loading. This is mainly due to formation of open and damaged cell structure. However, when glass powder is used as filler the thermal conductivity first decreases, but later increases with filler loading.

Effect of a Nanoclay on the Mechanical, Thermal and Flame Retardant Properties of Rigid Polyurethane Foam

“…The presence of reinforcing fillers in a polymer matrix improves the physical and mechanical properties of the polymer. Reinforcement plays a major role in this process which depends on surface activity and particle size of the fillers and the characteristics of the polymer-filler interaction (5). The increase in mechanical properties by the addition of a small amount of organoclay is due to the uniform and smaller cell size of the ONC filled PUF.…”

“…In general, the mechanical properties of the polymeric materials are improved by adding reinforcing fillers. The effects of different fillers on the mechanical properties of PUF have been reported (5). Interaction of fillers with different raw materials (like isocyanates) influences the properties of the PUF.…”

Obtenção E Caracterização De Espumas Rígidas De Poliuretano (Pur) Com Pó De Vidro Sodo-Cálcico (Pv) Do Rejeito Da Lapidação

“…Os demais corpos-de-prova destes compósitos apresentaram maiores valores de condutividade térmica que o PUR-puro, isto é, eles obtiveram o pior desempenho de isolação térmica; principalmente os corpos-de-prova com maiores percentuais de PV (PV20-100 e PV20-300). Thirumal et al (2007) observaram que houve uma redução no isolamento térmico com o aumento dos teores de SiO 2 e CaCO 3 . Isto foi explicado pela forma da estrutura celular gerada aberta e danificada.…”

“…As PUR são muito usuais devido a sua grande faixa de propriedades, principalmente como materiais estruturais (resistência mecânica e alta tenacidade) e isolação térmica. As propriedades da PUR são fortemente influenciadas pela estrutura, geometria e massa específica da espuma, bem como a adição, tamanho e formas das cargas na PUR (Thirumal et al, 2007). Saha et al (2008) estudaram os efeitos no desempenho térmico e mecânico da PUR (derivada de petróleo) causados pela adição de três tipos de nanopartículas (TiO 2 , nanoargila e nanofibra de carbono, CNF).…”

Investigating the influence of conduit residues on polyurethane plates

“…Polyurethane is a thermoplastic polymer often used in construction works due to its excellent performance as thermal and acoustic insulation [7,8,[13][14][15][16][17] . The physico-chemical properties of polyurethane are important for that purpose [5] .…”