scholarly journals Non-Furanic Humins-Based Non-Isocyanate Polyurethane (NIPU) Thermoset Wood Adhesives

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 372
Author(s):  
Xinyi Chen ◽  
Antonio Pizzi ◽  
Hisham Essawy ◽  
Emmanuel Fredon ◽  
Christine Gerardin ◽  
...  
Keyword(s):  
Linear Growth ◽  
Thermomechanical Analysis ◽  
Laser Desorption Ionization ◽  
Wood Panel ◽  
Ionization Time ◽  
Curing Period ◽  
Entanglement Network ◽  
Two Temperature ◽  
Second Peak ◽  
Better Than

Predominantly non-furanic commercial humins were used to prepare humin-based non-isocyanate polyurethane (NIPU) resins for wood panel adhesives. Pure humin-based NIPU resins and tannin–humin NIPU resins were prepared, the latter to upgrade the humins’ performance. Species in the raw humins and species formed in the NIPU resins were identified by Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI ToF) spectrometry and Fourier Transform Infrared (FTIR). Humins, fulvic acid and derivatives, humic acid and its fragments, some lignans present and furanic oligomers present formed NIPU linkages. Thermomechanical analysis (TMA) showed that as with other biomaterials-based NIPU resins, all these resins also showed two temperature peaks of curing, the first around 130 °C and the second around 220 °C. A decrease in the Modulus of Elasticity (MOE) between the two indicated that the first curing period corresponded to linear growth of the oligomers forming a physical entanglement network. This then disentangled, and the second corresponded to the formation of a chemical cross-linked network. This second peak was more evident for the tannin–humin NIPU resins. All the laboratory particleboard made and tested either bonded with pure humins or with tannin–humin NIPU adhesives satisfied well the internal bond strength requirements of the relevant standard for interior grade panels. The tannin–humin adhesives performed clearly better than the pure humins one.

Lignin-based adhesive crosslinked by furfuryl alcohol–glyoxal and epoxy resins

2019 ◽  
Vol 34 (2) ◽  
pp. 228-238 ◽  
Author(s):  
Jun Zhang ◽  
Wenli Wang ◽  
Xiaojian Zhou ◽  
Jiankun Liang ◽  
Guanben Du ◽  
...  
Keyword(s):  
Furfuryl Alcohol ◽  
Epoxy Resins ◽  
Phenol Formaldehyde ◽  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Oh Groups ◽  
Acidic Conditions ◽  
Matrix Assisted Laser ◽  
Better Than

Abstract In this work, a novel environmentally friendly lignin-based adhesive crosslinked with a furfuryl alcohol–glyoxal resin and epoxy resin (EPR) was used to bond particleboard. The results of 13C nuclear magnetic resonance and matrix-assisted laser desorption–ionization time-of-flight mass spectroscopy indicated that furfuryl alcohol and glyoxal reacted under acidic conditions and that–CH–(OH)–groups may be involved in the crosslinking of the lignin–furfuryl–glyoxal resin, which also easily crosslinked with EPR. The IB strength of the particleboard bonded with LFG + 9 % EPR adhesive was better than that of the particleboard bonded with lignin–furfuryl alcohol (LF) adhesive. Moreover, the modulus of elasticity of the LFG + 9 % EPR adhesive was higher than that of the LF and phenol-formaldehyde adhesives.

scholarly journals Silsesquioxane Derivatives as Functional Additives for Preparation of Polyethylene-Based Composites: A Case of Trisilanol Melt-Condensation

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2269 ◽  
Author(s):  
Dariusz Brząkalski ◽  
Robert E. Przekop ◽  
Bogna Sztorch ◽  
Paulina Jakubowska ◽  
Marek Jałbrzykowski ◽  
...  
Keyword(s):  
Laser Desorption ◽  
Mass Spectrometry Analysis ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Spectrometry Analysis ◽  
Functional Additives ◽  
Melt Condensation ◽  
Thermal Stability Of ◽  
Matrix Assisted Laser ◽  
Better Than

In this work, polyethylene (PE) composites were prepared with a series of completely condensed silsesquioxanes (SSQ), as well as with open-cage hepta(isobutyl)trisilanol silsesquioxane. The effect of the additives on the thermal, mechanical, rheological, and crystalline properties of the composites obtained was determined. The dispersion of trisilanol derivative within polymer matrix was slightly better than that of the other isobutyl compounds, suggesting condensation of the additive to less polar products of different structure, which was confirmed by thermogravimetry (TG) and matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) mass spectrometry analysis. The additives improved the thermal stability of polyethylene and formed composites of higher rigidity than the neat polyolefin. The results were compared to the literature data, with aminopropylhepta(isobutyl)silsesquioxane and vinylhepta(isobutyl)silsesquioxane being used partially as references, as PE composites thereof were reported earlier, but lacked some analytical results and required further investigation. It was proven that the practical upper loading limit for such silsesquioxane compounds as processing and functional additives for polyethylene should be fixed at around 1%.

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