Investigation of cellulose filaments as filler in rigid insulating polyurethane foam

Cellulose is a biopolymer that has broad potential applications including in building insulation, and it was studied for its potential as a filler material. A closed-cell polyurethane foam insulation formulation was developed, and cellulose filaments (CFs) were introduced at varying percentages. The viscosity and morphology of the formulations were studied, as were different foam properties, such as water vapor permeability, reaction kinetics, density, porosity, thermal conductivity, and compressive strength foams as a function of cellulose filaments content. A commercial foam was also tested as a reference. The cellulose filaments impacted the formulations’ viscosity, and all the properties of the resulting insulating material. For example, samples containing 5% of cellulose filaments were found to perform differently than samples containing 0%, 1% and 2.5% mainly due to agglomerate formation, which impacted cell size (about 0.1 mm2 at 0%, 1% and 2.5% versus a mean of over 0.4 mm2 at 5%), and differential vapor sorption (with a mass change of 2%wt at 0 parts per hundred of polyol versus 2.5%wt at 5% from 0% to 95% relative humidity). However, the required performances by the standards of polyurethane foam insulation material were always fulfilled regardless of the amount of cellulose filaments present

Investigation of Cellulose Filaments as Filler in Rigid Insulating Polyurethane Foam

Cellulose is a biopolymer that has broad potential applications including in building insulation, and it was studied for its potential as a filler material. A closed-cell polyurethane foam insulation formulation was developed, and cellulose filaments (CFs) were introduced at varying percentages. The viscosity and morphology of the formulations were studied, as were different foam properties, such as water vapor permeability, reaction kinetics, density, porosity, thermal conductivity, and compressive strength foams as a function of cellulose filaments content. A commercial foam was also tested as a reference. The cellulose filaments impacted the formulations’ viscosity, and all the properties of the resulting insulating material. For example, samples containing 5% of cellulose filaments were found to perform differently than samples containing 0%, 1% and 2.5% mainly due to agglomerate formation, which impacted cell size (about 0.1 mm2 at 0%, 1% and 2.5% versus a mean of over 0.4 mm2 at 5%), and differential vapor sorption (with a mass change of 2%wt at 0 parts per hundred of polyol versus 2.5%wt at 5% from 0% to 95% relative humidity). However, the required performances by the standards of polyurethane foam insulation material were always fulfilled regardless of the amount of cellulose filaments present

Understanding indentation, scratch and wear behavior of UV-cured wood finishing products

In the wood furniture and flooring industry, the protection and aesthetic properties of the final product often rely, at least partially, on the coatings applied on the wood surface. For flat surfaces, UV-cured coatings are often preferred due to their multiple advantages, such as high curing speeds, low volatile organic compounds (VOC) content, low energy consumption and high crosslinking densities. To increase the durability of interior wood products, the behavior of the protective coatings, while subjected to wear and deterioration, has to be understand in order to be enhanced. According to the type of solicitation, mar (i.e. shallow defect), scratches or indentations can be formed, which impact the coating’s appearance and can shatter the perception of the whole product. In this work, formulations based on different monomer-oligomer couples were prepared and photo-polymerized to investigate their performances. First, the glass transition temperature and the crosslinking density were determined to understand the contribution of both components in the polymeric network formed upon UV-curing. Then abrasion resistance, hardness, scratch and wear resistance were studied. The results showcased the importance of monomer and oligomer structure, functionality and main physical properties. In scratch experiments, hard and brittle coatings tend to display failures at lower loads than soft and ductile ones, whereas hard coatings are able to better withstand higher forces during indentations experiment. Friction experiments also caused subsurface tearing and fissuring in the soft coatings while generating several fractures in harder ones. Furthermore, the best overall mechanical resistance was obtained for the couples achieving high crosslinking density and a correlation between the crosslinking density of UV-cured coatings and their hardness was found. Interestingly, the investigation of tracks after scratch and wear experiments revealed a significant amount of information toward coatings behavior under various mechanical loads