Lignin-Based Low-Density Rigid Polyurethane/Polyisocyanurate Foams

Henry, Christián; Nejad, Mojgan

doi:10.1021/acs.iecr.2c03728

Cited by 10 publications

(2 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Density is a critical parameter that significantly affects the physical properties of PUFs. It is closely connected with material properties such as dimensional stability, thermal insulation, and various mechanical characteristics [ 49 ]. The density of PUFs was tested and is presented in Table 5 .…”

Section: Resultsmentioning

confidence: 99%

Bio-Based Alkali Lignin Cooperative Systems for Improving the Flame Retardant and Mechanical Properties of Rigid Polyurethane Foam

Li,

Liu,

et al. 2023

Polymers

View full text Add to dashboard Cite

Lignin was utilized as an environmentally friendly synergistic agent to augment the fire resistance and mechanical characteristics of rigid polyurethane foam (PUF)/melamine–formaldehyde resin ammonium polyphosphate (MFAPP). The incorporation of lignin significantly enhanced the charring capability and flame retardancy of PUF/MFAPP. Specifically, PUF/MFAPP12/A-lignin3 exhibited a charring residue of 23.1% at 800 °C, accompanied by an increase in the limiting oxygen index (LOI) to 23.1%, resulting in a UL-94 V-0 rating. The cone calorimeter test (CCT) revealed that the peak heat release rate (PHRR), total heat release (THR), smoke production rate (SPR), and total smoke production (TSP) values of PUF/MFAPP12/A-lignin3 were all lower than for pure PUF. MFAPP and alkali lignin exerted a noticeable influence on the physical and mechanical properties, leading to increases in density (35.4 kg/m3), thermal conductivity (32.68 mW/(m·K)), and compressive strength (160.5 kPa). Observations of the morphology and elemental composition of char residues after combustion indicated the formation of an intact, thick, and continuous char layer enriched with nitrogen and phosphorus elements, which acted as a protective shield for the underlying foam.

show abstract

Section: Resultsmentioning

confidence: 99%

Bio-Based Alkali Lignin Cooperative Systems for Improving the Flame Retardant and Mechanical Properties of Rigid Polyurethane Foam

Li,

Liu,

et al. 2023

Polymers

View full text Add to dashboard Cite

show abstract

“…Research has been conducted to modify lignin and castor oil to improve their reactivity in PU production 21 – 23 ; however, several of the proposed methods also have cost and toxicity issues 20 , 24 . In this study, the facile and low-cost production of PU foams was achieved by using unmodified lignin and castor oil in various ratios as partial substitutes for polyol.…”

Section: Introductionmentioning

confidence: 99%

Investigation of bio-based rigid polyurethane foams synthesized with lignin and castor oil

Kim,

Jin,

Choi

2024

Sci Rep

View full text Add to dashboard Cite

In this study, polyurethane (PU) foams were manufactured using kraft lignin and castor oil as bio-based polyols by replacing 5–20 wt% and 10–100 wt% of conventional polyol, respectively. To investigate the effects of unmodified bio-based polyols on PU foam production, reactivity and morphology within PU composites was analyzed as well as mechanical and thermal properties of the resulting foams. Bio-based PU foam production was carried out after characterizing the reagents used in the foaming process (including hydroxyl group content, molecular weight distribution, and viscosity). To compare the resulting bio-based PU foams, control foam were produced without any bio-based polyol under the same experimental conditions. For lignin-incorporated PU foams, two types, LPU and lpu, were manufactured with index ratio of 1.01 and 1.3, respectively. The compressive strength of LPU foams increased with lignin content from 5 wt% (LPU5: 147 kPa) to 20 wt% (LPU20: 207 kPa), although it remained lower than that of the control foam (PU0: 326 kPa). Similarly, the compressive strength of lpu foams was lower than that of the control foam (pu0: 441 kPa), with values of 164 kPa (lpu5), 163 kPa (lpu10), 167 kPa (lpu15), and 147 kPa (lpu20). At 10 wt% lignin content, both foams (LPU10 and lpu10) exhibited the smallest and most homogenous pore sizes and structures. For castor oil-incorporated PU foams with an index of 1.01, denoted as CPU, increasing castor oil content resulted in larger cell sizes and void fractions, transitioning to an open-cell structure and decreasing the compressive strength of the foams from 284 kPa (CPU10) to 23 kPa (CPU100). Fourier transform infrared (FT-IR) results indicated the formation of characteristic urethane linkages in PU foams and confirmed that bio-based polyols were less reactive with isocyanate compared to traditional polyol. Thermogravimetric analysis (TGA) showed that incorporating lignin and castor oil affected the thermal decomposition behavior. The thermal stability of lignin-incorporated PU foams improved as the lignin content increased with char yields increasing from 11.5 wt% (LPU5) to 15.8 wt% (LPU20) and from 12.4 wt% (lpu5) to 17.5 wt% (lpu20). Conversely, the addition of castor oil resulted in decreased thermal stability, with char yields decreasing from 10.6 wt% (CPU10) to 4.2 wt% (CPU100). This research provides a comprehensive understanding of PU foams incorporating unmodified biomass-derived polyols (lignin and castor oil), suggesting their potential for value-added utilization as bio-based products.

show abstract

Fractionated and purified hybrid poplar lignins as a polyol replacement in rigid polyurethane/polyisocyanurate foams

Henry,

Tindall,

Thies

et al. 2023

J of Applied Polymer Sci

Self Cite

View full text Add to dashboard Cite

This study introduces fractionated lignin as an innovative component in the formulation of rigid polyurethane/polyisocyanurate (PUR/PIR) foams. Low‐density PUR/PIR rigid foams were prepared by replacing 80% of the petrochemical‐based polyol with a hybrid poplar (HP) lignin, recovered via alkaline pretreatment, and also with a fraction of this lignin, isolated via the Aqueous Lignin Purification with Hot Agents (ALPHA) process. The as‐recovered HP and ALPHA‐fractionated HP lignins were characterized to determine hydroxyl content, molecular weight (Mw) distribution, and pH. Both lignin‐based foams met minimum standard requirements in terms of closed cell content, compression strength, and thermal conductivity. Notably, the foams made with ALPHA‐based lignin outperformed the as‐recovered lignin‐based foams in all measured foam properties. Moreover, the ALPHA‐based foam had comparable performance to the control foam (without lignin) except for density and even surpassed the control foam in closed cell content and compressive strength. This investigation of the molecular properties of lignin suggests that significant reductions in lignin average molecular weight and polydispersity (PDI) can positively impact the properties of lignin‐based rigid foams.

show abstract

Lignin-Based Low-Density Rigid Polyurethane/Polyisocyanurate Foams

Cited by 10 publications

References 66 publications

Bio-Based Alkali Lignin Cooperative Systems for Improving the Flame Retardant and Mechanical Properties of Rigid Polyurethane Foam

Bio-Based Alkali Lignin Cooperative Systems for Improving the Flame Retardant and Mechanical Properties of Rigid Polyurethane Foam

Investigation of bio-based rigid polyurethane foams synthesized with lignin and castor oil

Fractionated and purified hybrid poplar lignins as a polyol replacement in rigid polyurethane/polyisocyanurate foams

Contact Info

Product

Resources

About