Invented by Mikhail Yurevich Balakshin, Alex Berlin, Humbert Thomas DelliColli, Chadrick Adam Nathaniel Jordan Grunert, Vera Maximenko Gutman, Darwin Ortiz, Edward Kendall Pye, Suzano Canada Inc
The Suzano Canada Inc invention works as followsThe present invention provides derivatives from native lignin that have a certain amount of aliphatic-hydroxyl. It was surprising to find that derivatives of native-lignin with a certain amount of aliphatic hydroxide content can provide consistent and predictable antioxidant activities.
Background for Derivatives from native lignin
Native lignin, a complex organic macromolecule with amorphous structure and cross-linking, is an integral part of plant biomass. The lignin chemical structure is irregular, in that the different structural units (e.g. phenylpropane) are not linked in a systematic order. Native lignin is composed of a plurality of two monoolignols that are methoxylated in various degrees. (Trans-coniferyl and Trans-sinapyl) A third monolignol that is not methoxylated (Trans-p-coumaryl) also makes up the native lignin. These monolignols are used to build phenylpropanoid molecules. “Guaiacyl monoolignols, syringylmonolignols, and p-hydroxyphenylmonolignols are all polymerized by specific linkages into the native lignin macromolecule.
The extraction of native lignin during pulping usually results in the fragmentation of lignin into multiple mixtures with irregular components. The lignin fractions can also react with the chemicals used in the pulping procedure. The generated lignin fractions are referred to as technical lignins or lignins. It is hard to characterize and elucidate such a complex mixture of molecules. Therefore, lignins are described by the lignocellulosic material and the method of generating and recovering them from the lignocellulosic material. “Hardwood lignins are classified into softwood lignins and annual fibres lignins.
The pulping process depolymerizes native lignins into lignin particles that dissolve in pulping liquors. These lignin fragments are then separated from cellulosic fibers. Black liquors are post-pulping liquors that contain lignin, polysaccharide, and extractives. The pulping process will determine whether the liquors are called’spent alcohols’ or ‘black liquors. These liquors are usually considered by-products, and they can be combusted to get some energy in addition to the cooking chemicals. It is possible to precipitate or recover lignin-derived products from these liquors. “Each type of pulping used to separate cellulosic fibers from other lignocellulosic materials produces lignins with very different physicochemical, biochemical and structural properties.
Thermoplastics, and thermosets, are widely used for many purposes. Thermoplastics are polycarbonates and polyacrylates. They also include polyvinyls (polyvinyl chloride), polyvinyls (polyvinyl chloride), polystyrenes (polystyrene), polyamides(polyamides), polyacetates(polyacrylates), polypropylenes etc. The polyolefin market is large, with more than 100 millions metric tons of polyethylene and polypropylene produced annually. The physical and chemical properties can be negatively affected during manufacturing, processing, and use by various factors, such as heat, ultraviolet radiation, light and oxygen. It is obvious that it’s beneficial to avoid or minimize these problems. The increase in the recycling of materials has also increased the need to address this issue.
The adverse effects are often caused by degradation due to free radicals, UV radiation, heat and light, or environmental pollutants. In thermoplastic resins, a stabilizer, such as an anti-ozonant or UV block, is commonly added to aid in the production and extend the useful life. Stabilizers and antioxidants are often phenolic, amine, or phosphite-types. The use of these additives can have negative or unacceptable effects on the environment, health, safety, economy, and/or disposal. Furthermore, certain of these stabilizers/antioxidants can reduce the biodegradability of the product.
It has been suggested that the lignin could be a polymeric natural anti-oxidant with an acceptable level of toxicity, efficacy and environmental profile. For example, A. Gregorova et. al., Radial scavenging capability of lignin, and its effect upon processing stabilization of virgin or recycled polypropylene. Journal of Applied Polymer Science, 106-3 (2007) pp. 1626-1631; C. Pouteau et al. Antioxidant Properties in Polypropylene of Lignin, Polymer Degradation & Stability 81 (2003 9-18). For a number of reasons, lignin has not been widely used as an antioxidant despite its advantages. It is difficult to find lignins with consistent antioxidant activity. The processing of lignin can introduce substances which are not compatible with polyolefins or other chemicals. The cost of purifying and/or producing the lignin can make certain uses uneconomical.
The present invention provides derivatives from native lignin that have a certain amount of aliphatic hydrol. It has been discovered that derivatives of native-lignin with certain aliphatic contents can provide consistent and predictable antioxidant activities.
The term “native lignin” is used to refer to lignin in its natural state, as found in plant material. “Lignin in its native state in plant materials” is referred to as “native lignin”.
The term “lignin derivatives” is used in this document. The terms “lignin derivatives” and “derivatives from native lignin” refer to a lignin material extracted from lignocellulosic biomass. Refers to lignin extracted from lignocellulosic biomass. This material is usually a mix of chemicals that are produced during the extraction process.
The present invention provides native lignin derivatives with certain aliphatic contents of hydroxyl. Radical Scavenging Index, a measure for antioxidant activity, has shown that lignin derivatives with lower aliphatic hydroxyl content score higher. Selecting derivatives of native-lignin with a lower aliphatic content will result in a product that has a more predictable and higher antioxidant activity. The antioxidant activity of derivatives of native-lignin with an aliphatic content of 2.35 mmol/g and less is high. “For example, approximately 2.25 mmol/g, or less; or, approximately 2 mmol/g, or less; or, approximately 1.75 mmol/g.
The present invention is a method of recovering native lignin from lignocellulosic materials during or after the pulping process. The pulp can be made from a variety of lignocellulosic materials, including hardwoods and softwoods as well as annual fibres.
For example, hardwoods feedstocks may be chosen from Acacias, Aspens, Birches, Gums, Oaks, Poplars, Maples, Birches, Eucalyptus and their hybrids/combinations. Populus species may be used as hardwood feedstocks in the present invention. (e.g. Populus tremuloides), Eucalyptus spp. (e.g. Eucalyptus globulus), Acacia spp. (e.g. Acacia dealbata, and combinations/hybrids of them.
It has been shown that derivatives from native lignin derived from hardwood feedstocks with an aliphatic content of 2.35 mmol/g and less exhibit a high level of antioxidant activity. As an example, 2.25 mmol/g, 2 mmol/g, or 1.75 mmol/g.
The lignin derivates herein can, for example, be characterized by an aliphatic content of 0.001mmol/g, 0.1mmol/g, 0.2mmol/g, 0.4mmol/g, or 0.5mmol/g.
Derivatives from native lignin, according to the invention, coming primarily from hardwood feedstocks, tend to have NRSI values of 30, 40, 50, 60, 70, 80, 90, or more, or 120.
Araucaria, A. cunninghamii, A. angustifolia, A. araucana) and softwood Cedar (e.g. A. cunninghamii A. angustifolia A. araucana); softwood cedar (e.g. Juniperus virginiana; Thuja plicata; Thuja occidentalis; Chamaecyparis callitropsis nootkatensis. Cypresses (e.g. Chamaecyparis lawsoniana; European Yew, Rocky Mountain Douglas Fir; Firs (e.g. Abies balsamea, Abies alba, Abies procera, Abies amabilis); Hemlock (e.g. Tsuga canadensis, Tsuga mertensiana, Tsuga heterophylla); Kauri; Kaya; Larch (e.g. Larix decidua, Larix kaempferi, Larix laricina, Larix occidentalis); Pine (e.g. Pinus nigra, Pinus banksiana, Pinus contorta, Pinus radiata, Pinus ponderosa, Pinus resinosa, Pinus sylvestris, Pinus strobus, Pinus monticola, Pinus lambertiana, Pinus taeda, Pinus palustris, Pinus rigida, Pinus echinata); Redwood; Rimu; Spruce (e.g. Picea abies; Picea mariana; Picea rubens; Picea sitchensis and Picea glauca.Click here to view the patent on Google Patents.