Flammability and Thermal Properties of Rigid Polyurethane Foams Containing Wheat Straw Lignin

Due to development of new generation of biomass processing, the examination of novel lignin products for creation of lignin-containing PU remains actual up to now. For preparation of lignin containing PU in this study a novel BIOLIGNIN was used. BIOLIGNIN is extracted from wheat straw in organic acid media using biomass refinery technology. The influence of chemically non-modified BIOLIGNIN and oxypropylated BIOLIGNIN on flammability and thermal properties in rigid PU foams was studied. Improvement of flame resistance and thermal stability is observed if chemically non-modified lignin as well as oxypropylated lignin is used

Rigid Polyurethane Foams From Oxypropylated Wheat Straw Lignin

Polyols for rigid PU foams production are derived mostly from petrochemical products but it can be replaced by polyols obtained from natural raw materials (vegetable oils, tall oil, lignin etc.). Organosolve lignin from CIMV biorefinery (France) was used in our work. Different lignin and propylene oxide (PO) ratio (0.15-0.40) was used to get lignopolyols. Commercial polyol Lupranol 3300 was substituted by each lignopolyol in the compositions of rigid PU foams to investigate lignopolyol effect to density, closed cell content, physical-mechanical properties and water absorption. Lignopolyols synthesized from CIMV lignin by oxypropylation reaction is prospective material to obtain rigid PU foam with improved characteristics such as water absorption and compression strength

Thermal Degradation and Physical-mechanical Properties of Lignin-filled Rigid Polyurethane Foams

Nowadays, the synthesis of polymers from renewable resources, including polyurethane foams, has been actively investigated. In this work the potential application of lignin (CIMV, France) as non-reactive filler in tall oil amide (OH = 269 mg KOH/g, H2O = 0,2 wt.%) based rigid PU foams is studied. It was concluded that introducing lignin to rigid PU foams systems can increase physico-mechanical properties of foams

Flammability of Bio-Based Rigid Polyurethane Foam as Sustainable Thermal Insulation Material

One of the biggest disadvantages of rigid polyurethane foams is its low thermal resistance, high flammability, and high smoke production when burning. Greatest advantage of this thermal insulation material is its low thermal conductivity, which at 20–25 mW/(m·K) is superior to other commercially available insulation materials. In recent years polyurethane materials from renewable resources have been widely studied. But their use on industrial scale was limited due to inconstant performance and relatively high price of raw materials. Different bio-based raw materials, such as rapeseed oil and tall oil, could provide abundant feedstock for PU foam production. Decrease of flammability of PU materials conventionally is achieved by addition of flame retardants, halogen-containing compounds, and phosphates. It can be considered that halogenated fire retardants could have several health hazards, such as volatile compound emission from materials and toxic gas release during burning process. Expandable graphite could be an answer to this flammability problem. This chapter describes development of bio-based rigid polyurethane foams and their flammability reduction using sustainable flame retardants. Different expandable graphite intumescent flame retardants provided significant flammability reduction while maintaining low thermal conductivity of insulation materials

Reinforcement Efficiency of Cellulose Microfibers for the Tensile Stiffness and Strength of Rigid Low-Density Polyurethane Foams

Rigid low-density closed-cell polyurethane (PU) foams are widely used in both thermal insulation and structural applications. The sustainability of PU foam production can be increased by using bio-based components and fillers that ensure both enhanced mechanical properties and higher renewable material content. Such bio-based foams were produced using polyols derived from rapeseed oil and microcrystalline cellulose (MCC) fibers as filler. The effect of MCC fiber loading of up to 10 wt % on the morphology, tensile stiffness, and strength of foams has been evaluated. For estimation of the mechanical reinforcement efficiency of foams, a model allowing for the partial alignment of filler fibers in foam struts was developed and validated against test results. It is shown that although applying MCC fibers leads to modest gains in the mechanical properties of PU foams compared with cellulose nanocrystal reinforcement, it may provide a higher content of renewable material in the foams

Environmental Life Cycle Assessment of Rapeseed and Rapeseed Oil Produced in Northern Europe: A Latvian Case Study

There is a major international effort to improve the availability of data for life cycle assessment (LCA), as these assessments have become one of the main pillars driving European policy with respect to the sustainable use of resources. However, there is still a lack of data even for Europe. This study presents a cradle-to-farm gate assessment, or LCA, of winter and spring rapeseed produced in the northern European country of Latvia. The LCA model is based on an in-depth and up-to-date agricultural practice used in the region and covers the time span of 2008–2016. An LCA of rapeseed oil produced by cold pressing was carried out. The environmental impact assessment was calculated with the ReCiPe impact assessment method version 1.03, a hierarchical (H) perspective, along with the cumulative energy demand method v1.11. Cultivation of winter rapeseed has a lower environmental impact than cultivation of spring rapeseed due to higher agricultural inputs and higher yield. The greatest impact is on human health. Mineral fertilizers (production and application) and agricultural machinery are responsible for the greatest environmental impact. The results for the mill stage of rapeseed oil demonstrated that the choice of the allocation method has a significant impact on the environmental performance results