- Tuesday | 05/24/2011
Yo! Save the Trees!
First, we remind you of some earlier posts, one example being:
Scientists Convert Coal Ash to Cement | Research & Development; which includes the report: "New Use for Coal Ash: Material Provides Strong and Lightweight Alternative to Concrete – without Cement";
wherein it was demonstrated that fly ash from Coal-fired power plants could be utilized in the formulation of a lighter-weight substitute for traditional, Portland-type, cement-based concrete in some building and structural applications.
Such use of Coal ash is beneficial, aside from the fact that it serves to clean up "waste" through recycling and utilization, since it also reduces the amount of energy needed in the cement-making process; and, perhaps as importantly, it reduces as well the amount of Carbon Dioxide that would otherwise be generated, by replacing at least some of the Limestone that would have to be "calcined" into Calcium Oxide, the key ingredient of cement, as per the equation: CaCO3 = CaO + CO2.
In any case, via the two new reports we enclose herein, we learn that Coal ash and, indirectly, Carbon Dioxide, can both be utilized in the manufacture of another alternative construction material:
A few other things besides Fly Ash and CO2 are needed by the two, indirectly related, processes we report herein, to, ultimately, make synthetic lumber; but, only a few.
And, it might be well-worth the scavenger hunt to go get them, if it can help to restore some amity between our Coal-Mining brothers and sisters, and our Daisy-Sniffing, Tree-Hugging cousins, while at the same time creating a new industry and profit center for US Coal Country.
First, without trying to track down and link up to our earlier reports attesting to the fact, we again document, via the initial link, above, that Carbon Dioxide, recovered from whatever handy source, perhaps a Natural Gas cleaning, stripping, and compression plant, since it seems we might soon have a few of those around, can be used to replace truly noxious, but currently-used, substances, such as Phosgene, in the synthesis of urethane and polycarbonate plastics.
Comment follows excerpts from that link to:
"United States Patent 5,371,183 - Preparation of Urethane from Polyamine and Carbon Dioxide
Date: December, 1994
Inventors: William McGhee and Dennis Riley, MO
Assignee: Monsanto Company, St. Louis
Abstract: The present invention provides a process for preparing urethanes and carbonates from an amine or an alcohol, carbon dioxide and a hydrocarbyl halide. The amine or alcohol is reacted with carbon dioxide in a suitable solvent system and in the presence of an amidine or guanidine base, to form the ammonium carbamate or carbonate salt which is then reacted in a polar aprotic solvent with a hydrocarbyl halide. Polymer products can also be prepared utilizing this process or utilizing the resulting urethanes and carbonates under standard polymerization conditions.
Claims: The process for preparing polyurethanes comprising: bringing CO2 and a diamine or polyamine into reactive contact in a suitable solvent ... .
A process for preparing polyurethanes comprising: bringing CO2 and a diamine or polyamine into reactive contact in a suitable solvent and in the presence of a strongly basic nitrogenous compound ... .
Description: The present invention relates to a process for preparing urethanes and carbonates and, more particularly, relates to a new and useful process for preparing urethanes from amines, carbon dioxide and a hydrocarbyl halide and for preparing carbonates from alcohols, carbon dioxide and a hydrocarbyl halide. The present invention also relates to polymers prepared from such urethanes and/or carbonates.
Urethanes and carbonates are typically synthesized by the reaction of a primary amine or an alcohol with phosgene to form an isocyanate or carbonate salt. Thereafter, the isocyanate or carbonate is reacted with an alcohol to form the corresponding urethane or carbonate. Phosgene is very toxic and thus requires very careful handling from a product and worker safety standpoint. Isocyanates are sensitizers and are extremely toxic as well. Preparing urethane and carbonate products without using phosgene and in an economical manner, and preparing urethane products without generating isocyanates would be an achievement of considerable significance in the art.
(And, Carbon Dioxide makes that "achievement" possible.)
U.S. Pat. No. 4,467,089 discloses the preparation of certain carbamic acid derivatives (carbonates and carbamate esters) by the simultaneous reaction of a secondary amine and a tertiary amine with carbon dioxide to produce corresponding tertiary amine salts of N-substituted carbamic acid. The secondary and tertiary amines are brought together in equimolar proportions in the presence of excess carbon dioxide under mild conditions. The secondary amine reacts with CO2 in the presence of the tertiary amine to form the corresponding disubstituted tertiary ammonium carbamate salt. The salt is described as being useful as heat activatable delayed action catalysts, especially for use in polyurethane formulations.
Summary: The present invention provides a new and useful process for making urethanes and carbonates.
The present invention also provides a new and useful process for making polyurethanes and polycarbonates.
The process for preparing the subject urethanes and carbonates is characterized by reacting, in the presence of an amidine- or guanidine-type base, a suitable primary or secondary mono- or polyamine, or a suitable primary, secondary or tertiary mono-alcohol or polyol, with carbon dioxide."
And, so, Carbon Dioxide can replace truly noxious materials, and thus make it possible to manufacture "polyurethanes and polycarbonates" in a safer, more economical way, especially by avoiding the use of "very toxic" phosgene in the making of otherwise needed "isocyanates".
We'll take the opportunity to note, as well, without documenting the fact, that there are, or at least once were, some "polyol"s, as above, short for "poly alcohols", being made from organic, and thus CO2-recycling, sugars, such as sucrose. And, thus, the overall Carbon-recycling nature of this plastics-making invention could be even further enhanced.
Polyols and isocyanates are, typically, reacted to produce the polyurethanes.
Interestingly, such urethane and carbonate plastics, which are all by now instinctively familiar to us, since they're used in so many things, are not all that inherently rigid and strong, as opposed to just being "tough", for want of a better word, or durable, as they most often are.
Making "rigid" or "firm" structural items out of most polyurethanes and polycarbonates requires that they be "filled", while still in their resinous states, before they "set", with some sort of inert material, in the form of small grains or fibers that become bound in the plastic resin, and thus serve to help form a much more structurally competent composite.
We note that they can be "foamed", as well, to reduce their density while still imparting some rigidity.
That isn't of interest to us herein; but, we will further note that one of the foaming agents that was once commonly employed is Carbon Dioxide.
But, in the old days, one of the most commonly-used materials for "filling" solid, un-foamed polyurethanes and polycarbonates, for the purpose of imparting strength, was simply ground-up limestone.
It was cheap, inert and available.
Anyone who went bowling back in the 1970's, and became enamored with the then-newer polyurethane bowling balls, might be interested to know, that, somewhat like Fred Flintstone, they were knocking down pins with what were, in essence, chunks of limestone; just ones that were molded, instead of carved.
The weights of the balls were adjusted by adding more or less calcium carbonate powder, i.e., ground limestone, to the polyurethane resin from which the balls were formed.
So, once we have the "urethanes and carbonates" made, as above, in Monsanto's process of "United States Patent 5,371,183", by reacting a sugar-based resin, "a polyol, with carbon dioxide", we might need to add some filler to those products, so that they can be made more suitable for use in some specific applications.
One specific application might be in the manufacture of synthetic lumber.
And, interestingly, we might not have to expend the energy to quarry and grind up limestone to help make such CO2-derived plastics suitable for those uses.
Instead of powdered limestone, or other energy-demanding materials, we might be able to utilize the relatively-inert ash that results from generating electricity by the combustion of Coal.
As seen in, with further comment appended, the link to and excerpts from:
"US Patent Application 20080029925 - Filled Polymer Composite and Synthetic Building Material
Date: February, 2008
Inventor: Wade Brown, FL
Abstract: The invention relates to composite compositions having a matrix of polymer networks and dispersed phases of particulate or fibrous materials. The matrix is filled with a particulate phase, which can be selected from one or more of a variety of components, such as fly ash particles ... .
Claims: A method of continuously forming a molded material comprising: forming a composite mixture in an extruder, wherein the composite mixture comprises: (polyurethane reaction components, and) about 45 to about 85 weight percent of inorganic particulate material ...; and a catalyst; extruding the mixture through a die; and molding the mixture into a shaped article.
(And) wherein the shaped article is a building material (such as) lumber (or) roofing (or) siding.
Field: The invention relates to composite compositions having matrices of polymer networks and dispersed phases of particulate and/or fibrous materials, which have excellent mechanical properties, rendering them suitable for use in load bearing applications, such as in building materials.
The composites are stable to weathering, can be molded and colored to desired functional and aesthetic characteristics, and are environmentally friendly, since they can make use of recycled particulate or fibrous materials as the dispersed phase.
The invention (can be used to make) a variety of products, including synthetic lumber, roofing, and siding.
Polymeric composite materials that contain organic or inorganic filler materials have become desirable for a variety of uses because of their excellent mechanical properties, weathering stability, and environmental friendliness.
These materials can be relatively low density, due to their foaming, or high density when unfoamed, but are extremely strong, due to the reinforcing particles or fibers used throughout. Their polymer content also gives them good toughness (i.e., resistance to brittle fracture), and good resistance to degradation from weathering when they are exposed to the environment. This combination of properties renders some polymeric composite materials very desirable for use in building materials, such as roofing materials, decorative or architectural products, outdoor products, insulation panels, and the like.
In addition, the filler materials used need not be virgin materials, and can desirably be recycled fibers or particulates formed as waste or by-product from industrial processes.
(The) invention relates to composite compositions having a matrix of polymer networks and dispersed phases of particulate or fibrous materials. The polymer matrix contains a polyurethane network formed by the reaction of a poly- or di-isocyanate and one or more saturated polyether or polyester polyols, and an optional polyisocyanurate network formed by the reaction of optionally added water and isocyanate.
The matrix is filled with a particulate phase, which can be selected from one or more of a variety of components, such as fly ash."
Thus, in sum:
We can manufacture "synthetic lumber" by filling "polyurethane" with Coal plant "fly ash".
And, we can manufacture such "polyurethane" by reacting a, perhaps botanically-derived, "polyol, with carbon dioxide".
Yo! Save the Trees!
King Coal, it seems, through a few of his offspring, could do that, as well.