Valorization of isocyanates using castor oil-based protective strategies: Performance and comparison as waterborne adhesive additives

A novel nerol-segmented waterborne polyurethane coating for the prevention of dental erosion

“…PEBA and IPDI were placed in a three-necked flask equipped with a mechanical stirrer and reacted at 90 °C for 2 h. The mixture was then cooled to 75 °C and DMBA was added to continue the reaction for 2 h. At this point, there were still unreacted isocyanate groups in the reaction system as determined by the di- n -butylamine method as shown in Table 1 . 25 The mixture was cooled to 60 °C and nerol was added to react the mixture for 2 h to consume the –NCO groups sufficiently, and then triethylamine was added to neutralise the mixture for 15 min. Acetone was then added to adjust the viscosity of the prepolymer.…”

Eco-Friendly and High-Performance Bio-Polyurethane Adhesives from Vegetable Oils: A Review

“…The market is dominated by a wide variety of adhesives, many of which are synthetic and fossil-fuel-based. However, the dwindling fossil fuel resources and the focus on sustainable materials have led to increased interest in an eco-friendly alternative: vegetable oil-based adhesives [ 9 , 18 , 19 , 21 , 26 , 27 , 29 , 30 , 32 , 33 , 34 , 35 , 36 , 37 , 39 , 40 , 41 , 42 , 73 , 74 ], lignin-based adhesives [ 75 , 76 ], tannin-based adhesives [ 76 , 77 ], protein-based adhesives [ 78 , 79 ], and starch-based adhesives [ 80 , 81 , 82 ].…”

“…An optimistic approach to addressing the environmental impact of polyurethane adhesives (PUAs) is to employ vegetable oils as feedstock for their production. Vegetable oils from diverse sources like soybeans [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ], the castor plant [ 16 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ], and linseeds [ 27 , 28 ] bring several benefits, such as being abundant, renewable, and featuring appropriate chemical properties for adhesive formulations [ 18 , 19 , 21 , 26 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ]. Substituting petrochemical-based materials with vegetable oils could reduce dependence on fossil fuels while minimizing the carbon footprint associated with using and producing these adhesives [ 43 ].…”

Preparation of organosilicon and organofluorine synergistically modified amphiphilic branched polyurethanes and their application in diisocyanate emulsifiers

“…In recent years, the requirement for environmental protection and required higher isocyanate retention rate has prompted a growing need for water-based products modified by diisocyanate. [24][25][26][27][28][29] Isocyanates, as non-polar compounds, are poorly dispersed in waterborne adhesives, which can lead to uneven local mixing when blended into waterborne polymers. 30,31 To solve this problem, one approach is to introduce hydrophilic groups such as polyether and sulfonic acid groups on the isocyanate molecule by means of chemical modification.…”

“…Chen et al used castor oil to protect the isocyanate, and although a certain amount of NCO groups were retained, the NCO content decreased dramatically in a short time. 28 However, this approach is problematic in that isocyanate rapidly reacts with water to result in failure and storage in water is not stable. Furthermore, at the same time, the introduction of hydrophilic groups on the molecular chain causes the film to increasingly absorb water, which affects the performance of the paint film.…”