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Polylactic acid

Poly(lactic acid) or polylactide (PLA) is a thermoplastic aliphatic polyester derived from renewable resources, such as corn starch (in the United States), tapioca roots, chips or starch (mostly in Asia), or sugarcane (in the rest of the world). In 2010, PLA had the second highest consumption volume of any bioplastic of the world.[3] The name "poly(lactic acid)" does not comply with IUPAC standard nomenclature, and is potentially ambiguous or confusing, because PLA is not a polyacid (polyelectrolyte), but rather a polyester.[4] Production[edit] There are several industrial routes to usable (i.e. high molecular weight) PLA. Another route to PLA is the direct condensation of lactic acid monomers. Polymerization of a racemic mixture of L- and D-lactides usually leads to the synthesis of poly-DL-lactide (PDLLA), which is amorphous. Manufacturers[edit] As of June 2010, NatureWorks was the primary producer of PLA (bioplastic) in the United States. Chemical and physical properties[edit] Related:  how to make printing material

How Corn Plastics Are Made, And Why We Still Aren't Thrilled Our Discovery Channel sister site How Stuff Works has put out an interesting video on how corn plastics work. The video is informative about how corn plastics, or PLA, is produced. But it got us thinking about other issues with PLA that weren't really addressed.Corn plastics are controversial for a few reasons, not the least of which are that they use a resource that is energy intensive to produce, and because they can really gum up the works of recycling centers when not sorted properly. PLA can be sorted and recycled, but it takes some energy intensive processes to do it. Also, PLA looks a whole lot like other plastics such as PET. Many manufacturers and organizations call for PLA products to be very clearly marked when used, so that they can be more easily sorted. All-in-all, PLA can be a more eco-friendly option in some ways, but isn't an ideal solution to petroleum-based plastics.

ABS,PLA melting process in extruder and nozzle(private observed idea),that why some PLA will block extruder Filament melting process in nozzle Normal ABS: ABS is soft, there are two statue, soft and melting, Normal PLA: PLA is very hard,there are five statue exist in PLA, that are : amorphous,soft, crystallize,melting and degradation Amorphous: PLA is clear, very hard at this statue; Soft: when temperature higher than 60 deg, PLA will be soft, but still very strong that extruder can’t process ; Crystallize: when PLA on a temperature higher than 60 deg, and lower than melting point, retain for a while, PLA will crystal, crystal PLA is harder than amouphous; Melting(this temperature point is just the materials start to melt, can't process in extruder at this point): PLA is biomass materials, it is bad heat transfer, so on a same filament, some place close to nozzle are melting, other that a little far away from nozzle are not melting; Degradation: PLA is bad on heat stable, when retain on high temperature(>230 deg) for a while ,it will be degraded, flow like water . New formulation modify PLA Conclusion,

Ring-opening polymerization IUPAC definition for ring-opening polymerization A polymerization in which a cyclic monomer yields a monomeric unit which is acyclic or contains fewer cycles than the monomer. Note: If the monomer is polycyclic, the opening of a single ring is sufficient to classify the reaction as ring-opening polymerization. Modified from the earlier definition[1] .[2] General scheme ionic propagation. The driving force for the ring-opening of cyclic monomers is via the relief of bond-angle strain or steric repulsions between atoms at the center of a ring. Cyclic monomers that are polymerized using ROP encompass a variety of structures, such as: History[edit] Ring-opening polymerization (ROP) has been used since the beginning of 1900s in order to synthesize polymers. Nowadays, ROP plays an important role in industry such as production of nylon-6. Mechanisms of ROP[edit] Radical ring-opening polymerization[edit] Mechanism[edit] Radical ring-opening polymerization of vinyl cyclopropane Initiation[edit]

Make Cornstarch Plastic | Sail On! Experiment 2 Materials: 7 tablespoons of water 1 tablespoon of starch 2.5 teaspoon of vinegar 1.5 teaspoon of glycerin .5 teaspoon of baking soda Procedure l First, add one-half teaspoon of baking soda, then two tablespoons of water into a separate, small container, then set it aside for later. l Add seven tablespoons of cold water into a pan, then about one tablespoon of starch. Turn the burner to low heat, and then stir the mixture. Add the baking soda and water mixture, then let everything in the pan boil for 10 minutes. Get a sheet of aluminum foil so that you can carefully pour the gooey substance onto it for drying. Let the potato substance dry for one day in a sunny room, or place it into the oven for faster results. Mold or shape your newly created plastic. (from Like this: Like Loading...

PLA 4043D - Granulate - 500gr - natural - Plastic granulate - Plastic filament - Catalog Welcome to the ORCABOT website Since 2009 ORCABOT is selling 3D printers all over the world. One of our printers is the Orca, which is well known on the market. Since 2014 Orcabot has become part of Prodim International BV. Check out our BLOG for the latest news. All our prices are excl. For shipping & VAT estimations click "My Cart" in the upper right corner. Dialysis (biochemistry) In biochemistry, dialysis is the process of separating molecules in solution by the difference in their rates of diffusion through a semipermeable membrane, such as dialysis tubing.[1] Dialysis is a common laboratory technique that operates on the same principle as medical dialysis. In the context of life science research, the most common application of dialysis is for the removal of unwanted small molecules such as salts, reducing agents, or dyes from larger macromolecules such as proteins, DNA, or polysaccharides.[2] Dialysis is also commonly used for buffer exchange and drug binding studies. Diffusion is the random, thermal movement of molecules in solution (Brownian motion) that leads to the net movement of molecules from an area of higher concentration to a lower concentration until equilibrium is reached. Due to the pore size of the membrane, large molecules in the sample cannot pass through the membrane, thereby restricting their diffusion from the sample chamber.

Bioplastics – the quest for Open Source material production « Mindflip Chris, Mendel and myself have been involved in a bit of bioplastics experimentation over the past few days, which appears to be generating some interest. We’re doing the research/experimentation for a couple of reasons 1. It’s fun 2. Now to the meat, what everyone wants to know. The original recipe we used was but using cornstarch instead of potato starch. Our recipe then became: 7 parts water 1 part vinegar 1/2 part glycerine 1 1/2 parts starch With respect to the microwave, the mix was accidental (very unscientific I know), Chris was trying to replicate it on Sunday but without joy. From what I can remember the original microwave success came from the following approximate recipe: 1 part water 1 part starch splash glycerine bigger splash vinegar Microwave for too long until you have a gel rather than a liquid. Like I said, not very scientific.

Why are filament spools so expensive compared to pellets? ElectricMucus Wrote: ------------------------------------------------------- > What bugs me is as said before that the process > isn't that different, both come from cylindrical > extrusion. > How I understand it a machine used to make pellets > could also make filament (heck it even does, you > just have to roll it up). > The cooling process could be a little different or > will likely to be more complicated but I don't see > how that would affect prices to that extent. > The power needed to make pellets or filaments is > likely to be exactly the same. Since you seem to be completely unaware, most of the cost in extruding filament comes from the labor in spooling the filament and watching over the machine. Large spools are quite a bit cheaper than small spools since they don't need to be changed nearly as often. The diameter is also controlled by cool (and expensive) things like lasers, which are unnecessary when extruding pellets. Maybe you aren't looking at enough total volume?

Adhesion Adhesion of a frog on a wet vertical glass surface. Process of attachment of a substance to the surface of another substance. Note 1: Adhesion requires energy that can come from chemical and/or physical linkages, the latter being reversible when enough energy is applied. Note 2: In biology, adhesion reflects the behavior of cells shortly after contact to the surface. Note 3: In surgery, adhesion is used when two tissues fuse unexpectedly.[1] Surface energy[edit] Diagram of various cases of cleavage, with each unique species labeled.A: γ = (1/2)W11B: W12 = γ1 + γ2 – γ12C: γ12 = (1/2)W121 = (1/2)W212D: W12 + W33 – W13 – W23 = W132. If the surfaces are unequal, the Young-Dupré equation applies: W12 = γ1 + γ2 – γ12, where γ1 and γ2 are the surface energies of the two new surfaces, and γ12 is the interfacial tension. This methodology can also be used to discuss cleavage[disambiguation needed] that happens in another medium: γ12 = (1/2)W121 = (1/2)W212. Mechanisms of adhesion[edit] Strength[edit]

materials auger drill sizing for pellet extrusion Adsorption Brunauer, Emmett and Teller's model of multilayer adsorption is a random distribution of molecules on the material surface. Increase in the concentration of a substance at the interface of a condensed and a liquid or gaseous layer owing to the operation of surface forces. Note 1: Adsorption of proteins is of great importance when a material is in contact with blood or body fluids. Note 2: Adsorbed molecules are those that are resistant to washing with the same solvent medium in the case of adsorption from solutions. Similar to surface tension, adsorption is a consequence of surface energy. Adsorption is present in many natural, physical, biological, and chemical systems, and is widely used in industrial applications such as activated charcoal, capturing and using waste heat to provide cold water for air conditioning and other process requirements (adsorption chillers), synthetic resins, increase storage capacity of carbide-derived carbons, and water purification. Isotherms[edit] where and

Bioplastic - the plastic wrap that's good enough to eat | Video | Reuters.com video transcript PLEASE NOTE: THIS EDIT CONTAINS CONVERTED 4:3 MATERIAL According to the U.S. Environmental Protection Agency hundreds of millions of tons-worth of plastic bags are discarded every year. And this is where most of that plastic ends up. Sept. 25 - Argentine researchers have developed an edible, biodegradable alternative to conventional plastic for use in bags and as food wrappings.

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