A uniform dispersion of reactants is necessary to achieve a complete reaction involving multicomponents. In this study, we have examined the role of plasticizer in the reaction of two seemingly unlikely reactants: a highly crystalline hexamethylenetetramine (HMTA) and a strongly hydrogen bonded phenol formaldehyde resin. By combining information from NMR, infrared spectroscopy and differential scanning calorimetry, we were able to determine the role of specific intermolecular interactions necessary for the plasticizer to dissolve the highly crystalline HMTA and to plasticize the phenol formaldehyde resin in this crosslinking reaction. The presence of the plasticizer increased the segmental mobility, disrupted the hydrogen bonded matrix, and freed the hydroxyl units, which further increased the solubility of the HMTA. Both the endothermic and exothermic transitions are accounted for in the calorimetric data obtained. For the first time, it is possible to obtain the effective molar ratio of each component needed to complete the crosslinking reaction efficiently.

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A uniform dispersion of reactants is necessary to achieve a complete reaction involving multiple components. Using a combination of infrared spectroscopy, thermal analysis, and low field NMR, we have elucidated the role of a new class of nonreactive plasticizers on the crosslinking reaction between hexamethylenetetramine (HMTA) and phenol formaldehyde resin. These two seemingly dissimilar reactants are responsible for the exceptionally high mechanical strength in a number of organic–inorganic composites. The efficiency of the curing reaction is characterized by the changing functionality of HMTA. Infrared active vibrations are used to characterize the changing molecular structures as a function of temperature. The T1 spin‐lattice relaxation time is used for the characterization of segmental dynamics of the chains in the formation of the crosslinked product. The segmental mobility depends on the amount of crosslinking and the stiffness of the chain. This study shows that this new class of nonreactive plasticizer can induce highly crosslinked structures without any of the environmental impact of the current technology. An efficient crosslinking reaction in phenolic resin can be achieved by using methyl benzoate as a nonreacting plasticizer. Low field NMR, in conjunction with infrared spectroscopy (mid and near) and DSC, clarified the crosslinking reaction mechanism and the ensuing structure. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 206–213

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Virgin linear low-density polyethylene was subjected to pyrolysis in a fluidized bed reactor pilot plant segmented into three heating zones with both sand and Magnofil BT 80 catalyst as bed materials. The pyrolysis oil and wax products were extracted at an average bed temperature of 600 and 700 °C. The oil yield decreased between 600 (8.7 wt %) and 700 °C (8.1 wt %) in an inverse relationship with the reaction time (358 and 384 min, respectively). This was attributed to an increase in the vibration of the polyolefin polymer matrix as a result of the absorbed thermal energy with an increase in temperature. The experiments performed at 700 °C showed no wax formation but high yields of gaseous products and oils, which are more lucrative in managing accumulated plastic waste, of which polyethylene constitutes large proportions, via thermochemical conversion technologies. The estimated calorific value at 600 °C was 45.5 MJ kg–1, which is in the acceptable range for both diesel and gasoline fuel market specifications. The sulfur content in the pyrolysis oil was estimated to be 0.013% and was not affected by changes in the temperature of the fluidized reactor. However, desulfurization will be required in the future to obtain oil within acceptable ranges of clean fuels. In addition, to support this work’s results in obtaining fuels from such feedstock materials, the fuel range hydrocarbons were also analyzed. The diesel fuel hydrocarbon range (C10–C19) was between 37 and 60% in the pyrolysis oils examined. The results determined experimentally from the pilot-plant work herein are quite promising for sustainable fuel integration plans in the near future with existing petroleum refining complexes.