Biobased Polyurethane Composite Foams Reinforced with Plum Stones and Silanized Plum Stones

Abstract

In the following study, ground plum stones and silanized ground plum stones were used as natural fillers for novel polyurethane (PUR) composite foams. The impact of 1, 2, and 5 wt.% of fillers on the cellular structure, foaming parameters, and mechanical, thermomechanical, and thermal properties of produced foams were assessed. The results showed that the silanization process leads to acquiring fillers with a smoother surface compared to unmodified filler. The results also showed that the morphology of the obtained materials is affected by the type and content of filler. Moreover, the modified PUR foams showed improved properties. For example, compared with the reference foam (PUR_REF), the foam with the addition of 1 wt.% of unmodified plum filler showed better mechanical properties, such as higher compressive strength (~8% improvement) and better flexural strength (~6% improvement). The addition of silanized plum filler improved the thermal stability and hydrophobic character of PUR foams. This work shows the relationship between the mechanical, thermal, and application properties of the obtained PUR composites depending on the modification of the filler used during synthesis.

Bio-Based Rigid Polyurethane Foam Composites Reinforced with Bleached Curauá Fiber

“…The mean viscosity of each premixed polyols with the specific amount of CF filler is presented in Table 1 , as well as the results for the kinetic expansion for the produced RPUF composites. As expected, the greater amount of CF increased the dynamic viscosity significantly, with a higher result for CF 1 [ 3 ]. The higher reaction temperature is observed for CF 0.1, which can be related to the high contact between fillers and isocyanate, compared to the other groups.…”

“…Bio-based filled rigid polyurethane foams (RPUF) are a new class of polymer composite materials that present interesting properties. Some recent studies on the field proved that when a vegetable fiber, or a filler, is introduced, as a second phase, the cellular composite presents increases of properties, such as thermal stability, fire resistance, and photodegradation performance [ 1 , 2 , 3 , 4 , 5 , 6 ]. Technological properties, as decreases of thermal conductivity, water/moisture uptake, greater dimensional stability, and aesthetical appearance, antibacterial/anti-aging properties are also achieved [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ].…”

Evaluation of the Performance of Bio-Based Rigid Polyurethane Foam with High Amounts of Sunflower Press Cake Particles

“…The changes in characteristic foaming times can also be attributed to a higher dynamic viscosity of PUR foam mixtures with a higher content of SFP filler because it impedes the expansion and formation of larger cells. Very similar trends were observed in [ 33 ]’s study, where the authors incorporated silanised and non-treated plum stone filler into PUR foam compositions. Although, some natural raw materials such as natural cork have the opposite effect and reduce cream and gel times by 28% and 20%, respectively, and this phenomenon is attributed to the low thermal conductivity of cork agglomerates [ 34 ].…”

Vacuum-Based Impregnation of Liquid Glass into Sunflower Press Cake Particles and Their Use in Bio-Based Rigid Polyurethane Foam

“…For instance, PUR foam with SFP-20 has almost the same apparent density as LG-SFP-30 modified foam. The authors of [ 38 ] studied the impact of plum stone filler, silanized plum stone filler, and [ 3 ] algal cellulose on the performance of PUR foams and concluded that it could be attributed to the greater initial dynamic viscosity of PUR foams with unmodified filler particles.…”