Mechanical Properties Of Rigid Foam Research Articles

Processing and properties of rigid polyurethane foams based on bio-oils from microwave-assisted pyrolysis of corn stover

A new kind of rigid polyurethane (PU) foam was synthesized from the oil phase of bio-oils from microwaveassisted pyrolysis of corn stover. The recipes for the PU foams consisted of polyol-rich bio-oils, water as blowing agent, polyethylene glycol (PEG) as both polyol donor and plasticizer, diphenylmethane-4,4’-diisocyanate (polymeric MDI) as cross-linking agent, silicon-based surfactant, and tin-based catalyst. The mechanical properties of rigid foams were measured with universal testing machine (Instron4206). The effects of individual ingredients on the physical and mechanical properties of the foams were studied. It was found that water content, bio-oil content, and isocyanate dosage were important variables in making PU foams in terms of mechanical strength, density, and cellular structure.Under optimal conditions, the compression strength of the prepared PU foams reached 1130 kPa with a density of 152.9 g/L. The results show that bio-oils are potential renewable polyol sources for making rigid PU foams. Key words: rigid polyurethane foam, PU, bio-oil, microwave pyrolysis, corn stover, physical properties DOI: 10.3965/j.issn.1934-6344.2009.01.040-050 Citation: Jianping Wu, Yuanhua Wang, Yiqin Wan, Hanwu Lei, Fei Yu, Yuhuan Liu, Paul Chen, Lirong Yang, Roger Ruan. Processing and properties of rigid polyurethane foams based on bio-oils from microwave-assisted pyrolysis of corn stover. Int J Agric & Biol Eng, 2009; 2(1): 40

Mechanical Properties of Rigid Foam PVC-Clay Nanocomposites

The objective of this work is to investigate the effect of using different types of nanoclay fillers on the mechanical properties of rigid PVC foam. Four different types of commercially available nanoclays were used: Natural Calcium Montmorillonite (unmodified), Sodium Montmorillonite modified with a quaternary ammonium salt, Aluminum Magnesium Silicate clay, and Magnesium Lithium Silicate clay. The individual and combined effect of nanoclay concentration and blowing agent content in the polymer melt on the mechanical properties of the rigid foam is reported. Specific compressive strength, specific flexural modulus, and density were found to improve by introducing nanoclay in the polymer matrix. Whereas, tensile strength and modulus of elasticity showed some deterioration with the presence of nanoclay in the rigid PVC foam. On the other hand, impact strength and specific flexural strength did not show any significant changes.