Phenol formaldehyde resin analysis

R A Pethrick and B Thomson, NMR studies of phenol-formaldehyde resins - analysis of sequence structure in resins , Br Polym 11986 18 380. 

Recently, several reports of the flame-retardant properties of boron-containing bisphenol-A resins have appeared from Gao and Liu.89 The synthesis of a boron-containing bisphenol-A formaldehyde resin (64 and 65) (Fig. 42) from a mixture of bisphenol-A, formaldehyde, and boric acid, in the mole ratio 1 2.4 0.5, has been reported.893 The kinetics of the thermal degradation and thermal stability of the resins were determined by thermal analysis. The analysis revealed that the resin had higher heat resistance and oxidative resistance than most common phenol-formaldehyde resins. 

The importance of crosslinked polymers, since the discovery of cured phenolic formaldehyde resins and vulcanized rubber, has significantly grown. Simultaneously, the understanding of the mechanism of network formation, the chemical structure of crosslinked systems and the motional properties at the molecular level, which are responsible for the macroscopic physical and mechanical properties, did not accompany the rapid growth of their commercial production. The insolubility of polymer networks made impossible the structural analysis by NMR techniques, although some studies had been made on the swollen crosslinked polymers. 

Extraction of Cured, Modified Phenol-Formaldehyde Resins. A sample of the modified resin was spread as a thin coating on a sheet of aluminum foil and cured in an oven at 170 °C for 5 minutes. The cured resin was removed from the aluminum foil, weighed, and broken into small pieces that were placed in water (10 to 15 mL) for extraction at room temperature. After 1 to 2 hours, the water was decanted from the solid resin. The resin was extracted in this manner an additional three to four times. The residue from the water extraction at room temperature was dried and ground using a mortar and pestle. The ground resin was extracted with hot water in a Soxhlet apparatus for 24 hours. The room temperature extract and hot water extract were combined, concentrated, and diluted to a known volume for analysis. The quantity of modifier in the extract was determined by HPLC (77). 

Table 16.5. Electrical conductivity and elemental analysis data of polyacenic polymers and phenol-formaldehyde resin...

The thermogravimetric analysis (TGA) of solidified phenol-formaldehyde resins has shown that the ratio of the initial components influences the thermal stability of the polymers produced the most thermally resistant polymers were obtained with a phenohformaldehyde ratio of 0.5. 

The performance of several column packings has been assessed and it has been stressed that low eluent flow rates are necessary for high performance separation. The effects of water contamination in eluents has been studied by Berek et a/. " highlighting the need for rigorou dried systems. Phase equilibria studies in polymer-polymer-solvent systems have proved feasible using a dual detection system and could be extended in the future. Other applications are concerned with copolymer analysis, polydispersity, oligomers, and melamine-formaldehyde and urea— and phenol-formaldehyde resins. New techniques, recycle liquid SEC, phase-distribution chromatography, and the measurement of diffusion coefficients from GPC have been described. 

Matuana, L. M., Riedl, B. and Barry, O. (1993). Kinetic Characterization by Differential Enthalpy Analysis of Lignosulfonate-Based Phenol-Formaldehyde Resins. Eur. Polym. J., 29,483-490. 

Various ionization methods were used to bombard phenol-formaldehyde oligomers in mass spectroscopic analysis. The molecular weights of resole resins were calculated using field desorption mass spectroscopy of acetyl-derivatized samples.74 Phenol acetylation was used to enable quantitative characterization of all molecular fractions by increasing the molecular weights in increments of 42. 

Cure Rate of the Phenolated SEL Resins. 13C NMR spectra of the phenolated SEL formaldehyde-treated resins revealed the formation of methylol groups. A similar cure reaction to resole type phenolic resins is expected to occur with the phenolated lignin-based resins. Since cure rate normally determines production capacity of a board mill, it is important that new types of adhesives have at least the same cure rate as the conventional phenolic adhesives. Cure analysis of resins has usually been examined by... 

Journal of Applied Polymer Science 69, No. 11, 12th Sept. 1998, p.2175-85 IR SPECTROSCOPY AS A QUANTITATIVE AND PREDICTIVE ANALYSIS METHOD OF PHENOL-FORMALDEHYDE RESOL RESINS Holopainen T Alvila L Rainio J Pakkanen T T Joensuu,University Dynoresin Oy... 

The analysis of the co- condensation products of the commercial melamine formaldehyde resin Kauramin 700 (BASF AG) with the same trisubstituted phenols gives the stmctures given in Scheme 8. These structures confirm that the phenolic resin covalently bonds into the melamine network [120]. 

On the basis of the nature and reactive position of the monomers, elemental analysis UV-visible, IR, NMR spectral studies and taking into consideration the linear stmc-ture of other phenol -formaldehyde and the linear branched nature of irrea-formaldehyde polymers, the most probable structrrre has been proposed for p-CAF-1 copolymer resin, has been shown in Figitre 1. The morphology of the resin shows the transition between crystalline and amorphous natrrre, when compare to the other resin (Jadhao et al., 2005a), the p-CAF copolymer resin is more amorphous in nature, hence, higher metal ion-exchange capacity. 

The heat distortion temperature at 1.80 Mpa is the temperature that causes a beam loaded to 1.80 to deflect by 0.3 mm. If the heat distortion temperature is lower than the ambient temperature, -20 C is given. Polymers such as low-density polyethylene, styrene ethylene-butene terpolymer, ethylene-vinyl acetate copolymer, polyurethane, and plasticized polyvinyl chloride distort at temperatures below <50°C, whereas others, such as epoxies, polyether ether ketone, polydiallylphthalate, polydiallyl isophthalate, polycarbonate, alkyd resins, phenol formaldehyde, polymide 6,10 polyimide, poly-etherimides, polyphenylene sulfide, polyethersulfone, polysulfonates, and silicones, have remaikably high distortion temperatures in the range of 150°C to >300 C. Thermomechanical analysis has been used to determine the deflection temperature of polymers and sample loading forces (i.e., plots of temperature vs. flexure). 

More details on the reaction rates and structures produced in a phenol-formaldehyde resole resin has been obtained in a carbon-13 NMR and gel permeation chromatography (gpc) study [34]. In this study an alkaline resole resin typrint of the wood products binder industry was prepared as described in preparation 2-8 below and samples withdrawn at various stages for analyses by NMR and GPC. Details of the analysis are described in the referenced paper, and the reader is referred to this... 

TVA and Differential Distillation Analysis (or SATVA) have been applied to studies on the effect of chlorinated hydrocarbon fire retardants [945, 946]. Rigby [947] has studied vapour evolution from LDPE cable insulation material (20-60 mg) by means of TVA-ToFMS, a form of in-source TD-MS, and identified Santonox R and traces of the cross-linking agent dicumyl peroxide in the low-temperature peak of the TVA curve. The TVA curves of commercial LDPE and of fl eshly prepared LDPE/Santonox suggested that in commercial samples Santonox was distributed closer to the surface than in freshly prepared ones. The detection limit (using ToF-MS) for Santonox bulk-distributed in LDPE was about 0.01%. Chiantore et al. [948] have characterised a phenol-formaldehyde (PF) resin by means of TVA (to isolate the lower-MW components) and SEC (both on volatile fractions and residues). 

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