Effect of reactant ratio and temperature on the characteristics of phenol–formaldehyde foams

Singh, Daljit; Ohri, Suneeta

doi:10.1002/app.1982.070270408

Cited by 4 publications

(4 citation statements)

References 1 publication

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“…Li et al reported that different molar ratios of phenol to paraformaldehyde significantly influenced the properties and molecular structure of the synthesized resin. Singh and Ohri reported that both reaction temperature and speed were closely related to the activity of PF resin.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of phenol‐urea‐formaldehyde foaming resin used to block air leakage in mining

Zhao

Cheng

et al. 2014

Polymer Composites

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In this study, phenol, urea, and paraformaldehyde were used as the monomers for the one‐step synthesis of phenol‐urea‐formaldehyde (PUF) foaming resin that was used to block air leakage in mining. An orthogonal test was used to study the effects of urea amount, catalyst amount, reaction temperature, and reaction time on the foaming property of the resin. The results showed that the optimum parameters for synthesizing PUF resin are as follows: 1 mol phenol, 0.5 mol urea, 3 mol formaldehyde equivalents of paraformaldehyde, and 0.05 mol catalyst at 75°C for 3 h. The infrared and 13C nuclear magnetic resonance spectra of the PUF resin showed that the chemical structure of the PUF resin was significantly different from that of phenol‐formaldehyde resin, indicating that a copolymerization reaction has occurred among the three components, that is, phenol, urea, and paraformaldehyde. In this study, PUF foam was prepared from catalysts and PUF resin. The results showed that the foaming capacity and oxygen index of the PUF foam were significantly improved by using urea, whereas the shrinking percentage decreased with no change in compression strength. POLYM. COMPOS., 35:2056–2066, 2014. © 2014 Society of Plastics Engineers

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Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of phenol‐urea‐formaldehyde foaming resin used to block air leakage in mining

Zhao

Cheng

et al. 2014

Polymer Composites

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“…With deficiencies such as the mechanical strength, high open cell content, and corrosion having been resolved to a great extent (except for friability), this study was undertaken to reduce the overly high contents of free phenol and free formaldehyde in phenolic foam. A trend of decreasing free phenol and free formaldehyde during the synthesis of resols has been reported in recent years 1–4. Manfredi et al5 gave the results of free phenol and free formaldehyde contents with different formaldehyde/phenol (F/P) molar ratios.…”

Section: Introductionmentioning

confidence: 91%

“…A trend of decreasing free phenol and free formaldehyde during the synthesis of resols has been reported in recent years. [1][2][3][4] Manfredi et al 5 gave the results of free phenol and free formaldehyde contents with different formaldehyde/phenol (F/P) molar ratios. We investigated the literature and found that there was little information on reducing the contents of free phenol and free formaldehyde in phenolic foam.…”

Section: Introductionmentioning

confidence: 99%

Reducing the contents of free phenol and formaldehyde in phenolic foam

Lin

Yan

et al. 2003

J of Applied Polymer Sci

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ABSTRACT:The problem of overly high contents of remnant monomers (free phenol and free formaldehyde) in phenolic foam was studied. Free phenol was characterized by iodimetry, and free formaldehyde was characterized by a hydroxylamine hydrochloride method. The effect of the phenol/formaldehyde molar ratios and the reaction temperature on the contents of the remnant monomers was examined. The effect of adding urea on the content of free formaldehyde was investigated. The effect of the foaming process on the contents of the remnant monomers was examined in detail. Phenolic foams in which the content of free phenol was 0.09% and the content of free formaldehyde was less than 0.1% were successfully prepared. A prepolymer of polyurethane, which toughened the phenolic foam, lowered the contents of free phenol and free formaldehyde.

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“…Fire and environmental pollution problems caused by inflammable foams have aroused worldwide public concern [1,2]. In the past few decades, considerable research efforts have been devoted to the formulation and characterization of new ecologically friendly flame-retardant foams that can be applied in indoor decoration and wall heat-preservation fields [3].…”

Section: Introductionmentioning

confidence: 99%

New Light Flame-Retardant Materials of Reinforced Melamine-Urea-Formaldehyde (MUF) Foam with Wood Pulp Fiber: Preparation and Properties Evaluation

Zhuang

Feng

et al. 2011

AMR

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New composite foams were prepared by using Melamine-Urea-Formaldehyde (MUF) resin and wood pulp fiber as raw materials with co-foaming method at 70°C in the opening mould. The study of the composites foam microstructure showed good adhesion between MUF matrix foam and wood pulp fiber. The flame-retardant, mechanical, anti-brittleness and insulation properties of composite foam were excellent. The results indicated that composites had superior properties enough to replace the conventional foam materials.

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Effect of reactant ratio and temperature on the characteristics of phenol–formaldehyde foams

Cited by 4 publications

References 1 publication

Synthesis and characterization of phenol‐urea‐formaldehyde foaming resin used to block air leakage in mining

Synthesis and characterization of phenol‐urea‐formaldehyde foaming resin used to block air leakage in mining

Reducing the contents of free phenol and formaldehyde in phenolic foam

New Light Flame-Retardant Materials of Reinforced Melamine-Urea-Formaldehyde (MUF) Foam with Wood Pulp Fiber: Preparation and Properties Evaluation

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