Thermodynamic properties of phenol–formaldehyde resin

Abstract

SynopsisCharacterization measurements of a commercial phenol-formaldehyde resin prepared from constituedts including phenol and formaldehyde in the molar ratio 1:1.33 are reported. The measurements consist of l) the linear thermal expansion coefficient between approximately 85 and 270'K; 2) the specific heat capacity between approximately 6 and 100'K; 3) the Young's modulus a t room temperature. A critical examination of the data reveals that: 1) the vibrational behavior is predominantly that of a three-dimensional assembly; 2) as far as data available from other sources permit an assessment to be made, the principle of additivity appears to be applicable to the specific heat capacity between approximately 50 and 100'K; and 3) the data lie near the limit of an empirical relationship observed between the Young's modulus and linear thermal expansion coefficient of other polymers.

Molecular dynamics simulations of phenolic resin: Construction of atomistic models

“…System V5 has slightly higher CTE values for D>60%, which could be attributed to the additional free volume associated with lower densities. Experimental results for coefficients of thermal expansion range from 104 to 310 ppm/C° [65,71,72]. If we compare our CTE results for degrees of cross-linking comparable to experimental curing (60%<D<85%), then our results of 91 to 236 pppm/C° agree well with experimental results.…”

“…A density difference of 0.08 g/cm 3 yields a change of 1.9 GPa in the Young's modulus of the 9-ring ortho-ortho structures at D=85%. The Young's modulus calculated for samples with higher densities produced values consistent with the experimental range of (3.5 -6 GPa) [37,66,[72][73][74]. However, experimental determination of degree of curing is non-trivial and therefore a rigorous comparison between our simulations and experimental data is challenging.…”

Thermal expansion and mechanical properties of phenolic resin/ZrW2O8 composites

“…The bulk and shear moduli values for ZrW 2 O 8 10 corresponding to 74.5 and 33.9 GPa, respectively, have been used. The bulk modulus ( K ) and Poisson's ratio (ν) for phenolic resin are reported to be 4.5 GPa and 0.37, respectively 11. Therefore, the shear modulus ( G ) value of 1.28 GPa for the phenolic resin is determined by the following equation12: …”

“…The bulk modulus (K) and Poisson's ratio (m) for phenolic resin are reported to be 4.5 GPa and 0.37, respectively. 11 Therefore, the shear modulus (G) value of 1.28 GPa for the phenolic resin is determined by the following equation 12 : ZrW 2 O 8 has two cubic phases at the ambient pressure (a-phase below 423 K and b-phase above 423 K) and one orthorhombic phase at high pressures (gphase). The CTEs of all the three phases are negative but vary in magnitude beginning from CTE a 5 28.7 3 10 26 K -1 , CTE b 5 24.9 3 10 26 K -1 , and CTE g 5 21. sites with 19-25 vol % of ZrW 2 O 8 fillers shows a maximum value of 130 MPa, which is 45% greater than that of the phenolic resin without fillers-89.4 MPa.…”

Computational and Experimental Study of Phenolic Resins: Thermal–Mechanical Properties and the Role of Hydrogen Bonding

“…Experimental characterization of phenolic resins has spanned many decades due to their versatile applications in industry, , academics, − and government. − Numerous experimental results on isolated phenolic resins as well as in composites have been published to understand their characteristics and properties as a function of cure, − processing, − and composite design. ,− In addition, experimental properties such as the coefficients of thermal expansion, ,, thermal conductivity, ,, and elastic moduli ,, have been reported. Phenolic resins also have disadvantages, however, which include void formation and shrinkage that occur during processing as well as its brittle nature when highly cured.…”