PF: Phenol-Formaldehyde Resin

General Properties

Short Name:

Name:

Phenol-Formaldehyde Resin

Phenol-formaldehyde resins (PF) are thermosetting materials, produced by polycondensation of phenol and formaldehyde. The phenol-formaldehyde resin, Bakelite, was the first fully synthetic, industrially produced polymer. Since the Curing (Crosslinking Reactions)Literally translated, the term “crosslinking“ means “cross networking”. In the chemical context, it is used for reactions in which molecules are linked together by introducing covalent bonds and forming three-dimensional networks.curing of PF resins is a polycondensation reaction, high-pressure crucibles are recommended.

Structural Formula

Properties

Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.Glass Transition Temperature	70 to 120°C
Melting Temperatures and EnthalpiesThe enthalpy of fusion of a substance, also known as latent heat, is a measure of the energy input, typically heat, which is necessary to convert a substance from solid to liquid state. The melting point of a substance is the temperature at which it changes state from solid (crystalline) to liquid (isotropic melt).Melting Temperature	-
Melting Temperatures and EnthalpiesThe enthalpy of fusion of a substance, also known as latent heat, is a measure of the energy input, typically heat, which is necessary to convert a substance from solid to liquid state. The melting point of a substance is the temperature at which it changes state from solid (crystalline) to liquid (isotropic melt).Melting Enthalpy	-
Decomposition reactionA decomposition reaction is a thermally induced reaction of a chemical compound forming solid and/or gaseous products. Decomposition Temperature	450 to 555°C
Young's Modulus	5600 to 12000 MPa
Coefficient of Linear Thermal Expansion (CLTE/CTE)The coefficient of linear thermal expansion (CLTE) describes the length change of a material as a function of the temperature.Coefficient of Linear Thermal Expansion	15 to 50 *10^-6/K
Specific Heat Capacity	1.0 to 1.3 J/(g*K)
Thermal ConductivityThermal conductivity (λ with the unit W/(m•K)) describes the transport of energy – in the form of heat – through a body of mass as the result of a temperature gradient (see fig. 1). According to the second law of thermodynamics, heat always flows in the direction of the lower temperature.Thermal Conductivity	0.35 to 0.70 W/(m*K)
DensityThe mass density is defined as the ratio between mass and volume. Density	1.40 to 1.80 g/cm³
Morphology	Thermoset
General properties	Very hard and stiff. Good chemical resistance. Low inflammability
Processing	Compression, injection molding, extrusion molding, transfer molding, foaming
Applications	Electrical industry (e.g., for circuit boards, plugs). Building industry (weather-resistant glue, for production of insulating materials). Vehicle construction. Matrix for fiber-reinforced composites

NETZSCH Measurement

Instrument	DSC 204 `F1` `Phoenix^®`
Sample Mass	26.26 mg
IsothermalTests at controlled and constant temperature are called isothermal.Isothermal Phase	10 min
Heating/Colling Rates	5 K/min 1^st heat. 10 K/min cooling 20 K/min 2^nd heat.
Crucible	High-pressure steel crucibles, closed
Atmosphere	N₂ (40 ml/min)

Evaluation

The 1^st heating (blue) shows a Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.glass transition at approx. 48°C (midpoint) with an overlapping enthalpy RelaxationWhen a constant strain is applied to a rubber compound, the force necessary to maintain that strain is not constant but decreases with time; this behavior is known as stress relaxation. The process responsible for stress relaxation can be physical or chemical, and under normal conditions, both will occur at the same time. relaxation, followed by a multi-step ExothermicA sample transition or a reaction is exothermic if heat is generated.exothermal Curing (Crosslinking Reactions)Literally translated, the term “crosslinking“ means “cross networking”. In the chemical context, it is used for reactions in which molecules are linked together by introducing covalent bonds and forming three-dimensional networks.curing effect with peak temperatures of 141°C and 206°C and a total enthalpy of 191 J/g. In the following 2^nd heating (red), the Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.glass transition shifted to approx. 72°C (midpoint) as a result of the extensive Curing (Crosslinking Reactions)Literally translated, the term “crosslinking“ means “cross networking”. In the chemical context, it is used for reactions in which molecules are linked together by introducing covalent bonds and forming three-dimensional networks.curing in the previous heating step.