Polyurethane Foams for Domestic Sewage Treatment

Kairytė

et al. 2021

IJMS

Rigid polyurethane (PUR) foams reinforced with 1, 2, and 5 wt.% of salvia filler (SO filler) and montmorillonite-modified salvia filler (MMT-modified SO filler) were produced in the following study. The impact of 1, 2, and 5 wt.% of SO filler and MMT-modified SO filler on the morphological, chemical, and mechanical properties of PUR composites were examined. In both cases, the addition of 1 and 2 wt.% of SO fillers resulted in the synthesis of PUR composites with improved physicomechanical properties, while the addition of 5 wt.% of SO fillers resulted in the formation of PUR composites with a less uniform structure and, therefore, some deterioration in their physicomechanical performances. Moreover, the results showed that the modification of SO filler with MMT improved the interphase compatibility between filler surface and PUR matrix. Therefore, such reinforced PUR composites were characterized by a well-developed closed-cell structure and improved mechanical, thermal, and flame-retardant performances. For example, when compared with reference foam, the addition of 2 wt.% of MMT-modified SO filler resulted in the formation of PUR composites with greater mechanical properties (compressive strength, flexural strength) and improved dynamic-mechanical properties (storage modulus). The PUR composites were characterized by better thermal stability as well as improved flame retardancy—e.g., decreased peak rate of heat release (pHRR), reduced total smoke release (TSR), and increased limiting oxygen index (LOI).

Section: Introductionmentioning

confidence: 99%

Mechanically Strong Polyurethane Composites Reinforced with Montmorillonite-Modified Sage Filler (Salvia officinalis L.)

Kairytė

et al. 2021

IJMS

“…Polyurethanes are obtained by the formation of urethane bonds due to the reaction of polyols and polyisocyanates, discovered in 1937 by Bayer [ 6 ]. The use of properly selected polyols and polyisocyanates allows obtaining polyurethane materials in various forms, including elastomers, coatings, adhesives, rigid and flexible foams, films, and fibers [ 3 , 7 , 8 ]. As a result of such varieties in the microstructure and diversity properties of the obtained materials, polyurethanes have been widely used in many sectors, such as thermal and electrical insulation and coatings, biomedical applications, construction, high-performance adhesives, the footwear market, and packaging or furniture [ 9 , 10 , 11 , 12 , 13 , 14 ].…”

Section: Introductionmentioning

confidence: 99%

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

Strąkowska

et al. 2021

IJMS

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.

“…Polyurethanes (PU) are one of the most widely used groups of polymer materials. They can be produced in various forms, including elastomers, adhesives, coatings, and porous materials, which are divided into two main groups—rigid polyurethane foams (RPUFs) and flexible polyurethane foams (FPUFs) [ 1 , 2 , 3 , 4 ]. This enables the use of polyurethane products in many applications, such as thermal and electrical insulation materials, construction, packaging, furniture, or biomedical applications [ 5 , 6 , 7 , 8 , 9 ].…”

Section: Introductionmentioning

confidence: 99%

Vermiculite Filler Modified with Casein, Chitosan, and Potato Protein as a Flame Retardant for Polyurethane Foams

Strąkowska

et al. 2021

IJMS

In this study, polyurethane (PU) composite foams were modified with 2 wt.% of vermiculite fillers, which were themselves modified with casein, chitosan, and potato protein. The impact of the fillers on selected properties of the obtained composites, including their rheological (foaming behavior, dynamic viscosity), thermal (temperature of thermal decomposition stages), flame-retardant (e.g., limiting oxygen index, ignition time, heat peak release), and mechanical properties (toughness, compressive strength (parallel and perpendicular), flexural strength) were investigated. Among all the modified polyurethane composites, the greatest improvement was noticed in the PU foams filled with vermiculite modified with casein and chitosan. For example, after the addition of modified vermiculite fillers, the foams’ compressive strength was enhanced by ~6–18%, their flexural strength by ~2–10%, and their toughness by ~1–5%. Most importantly, the polyurethane composites filled with vermiculite filler and modified vermiculite fillers exhibited improved flame resistance characteristics (the value of total smoke release was reduced by ~34%, the value of peak heat release was reduced by ~25%).