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Reinforcing materials and fillers In many plastics, reinforcing materials and fillers occupy a considerable proportion. In order to improve the strength and rigidity of plastic products or reduce production costs, various fiber materials or inorganic substances are added. The most commonly used reinforcement materials are: glass fiber, asbestos, quartz, carbon black, silicate, calcium carbonate, metal oxides, etc. Coupling agent Coupling agent refers to a class of substances that can improve the interface properties between fillers and polymer materials. Usually there are two functional groups in the molecular structure of the coupling agent: one can chemically react with the polymer matrix or have good compatibility; the other can form chemical bonds with the inorganic filler. For example, silane coupling agent, the general formula of which can be written as RSiX3, where R is an active functional group that has affinity and reactivity with polymer molecules, such as vinyl, chloropropyl, epoxy, methacryloyl, amine and mercapto, and X is an alkoxy group that can be hydrolyzed, such as methoxy, ethoxy, etc. At present, organosilane is the most widely used coupling agent, and organotitanate is a more efficient coupling agent. Cross-linking agent Crosslinking agents are mainly used in polymer materials (rubber and thermosetting resins). Because the molecular structure of the polymer material is a linear structure, the strength is low when it is not cross-linked and it’s easy to break. A network structure is formed, which improves the strength and elasticity of the rubber. The crosslinking agent used in the rubber is mainly sulfur, and an accelerator is added. The general cross-linking agent mostly refers to organic peroxide. For instance, dicumyl peroxide can be used as the cross-linking agent for polyethylene. Foaming agent Foaming agent is a kind of substance that can make rubber and plastic in a liquid or plastic state to form a microporous structure. According to the mechanism of action, foaming agents can be divided into physical foaming agents and chemical foaming agents. Physical foaming agent is a type of compound that relies on the change of its physical state during the foaming process to achieve the purpose of foaming; while chemical foaming agent will thermally decompose at a certain temperature to generate one or more gases to foam the polymer. Nucleating agent Nucleating agent is suitable for incomplete crystalline plastics such as polyethylene and polypropylene. By changing the crystallization behavior of the resin, it can speed up the crystallization rate, increase the crystallization density and promote the miniaturization of the grain size, so as to shorten the molding cycle, improve the transparency and surface of the product. Colorant Colorants are insoluble in common solvent chemicals. To obtain ideal coloring properties, the pigments need to be uniformly dispersed in the plastic by mechanical methods. Inorganic pigments have excellent thermal stability and light stability, low price, but relatively poor tinting strength and high relative density. In contrast, organic pigments have high tinting strength, bright color, complete color spectrum, and low relative density. Colorants mainly include masterbatches and optical brighteners. Masterbatch is a kind of aggregate prepared by uniformly loading super-constant pigments or dyes in resin. Its basic composition includes: pigments or dyes, carriers, dispersants, additives. Fluorescent whitening agent is a fluorescent dye, and can be classified into several sub-categories, including carbocyclics, triazinylaminostilbene, stilbene-triazoles, benzoxazoles, furans, benzofurans and benzimidazoles, 1,3-diphenyl Base-pyrazoline, coumarin, naphthalimide and others. Antibacterial agents With the continuous enhancement of people's safety awareness, more and more people begin to buy antibacterial plastic products. Antibacterial agents are used in antibacterial plastics. Antibacterial agents refer to chemical substances that can keep the growth or reproduction of certain microorganisms, such as bacteria, fungi, yeast, algae and viruses, etc., below a necessary level for a certain period of time. Antibacterial agents are substances with bacteriostatic and bactericidal properties. Flame retardant The additives that slow down the combustion performance of plastics are called flame retardants. Most of the plastics containing flame retardants are self-extinguishing or have the effect of slowing down the burning rate Antistatic agent Any object has its own electrostatic charge, which can be negative or positive. The accumulation of electrostatic charges affects or even harms life or industrial production. Chemical substances that guide/eliminate the accumulated harmful charges so that they do not cause inconvenience or harm to production or life are called antistatic agents. Antistatic agents generally have the characteristics of surfactants, and have both polar groups and non-polar groups in structure. The commonly used polar groups are: anions of carboxylic acid, sulfonic acid, sulfuric acid, phosphoric acid, cations of amine salts, quaternary ammonium salts, and -OH, -O- and other groups. The commonly used non-polar groups, namely, lipophilic groups or hydrophobic groups, include alkyl groups, alkaryl groups, and the like. Antistatic agents can be of five basic types: derivatives of amines, quaternary ammonium salts, sulfates, phosphates, and derivatives of polyethylene glycols. Alfa Chemistry  is chemical supplier that provides a comprehensive range of stabilizers, including antioxidant, flame retardant, heat stabilizer, light stabilizer, mould inhibitor, optical brightener, plasticizer, and synthetic auxiliary. All can be used as additives for plastics. ... View more

Benefits of forced degradation test The degradation pathway of the drug is closely related to the molecular structure of the drug. The ester group or amide bond in the molecular structure may be hydrolyzed under acid-base catalysis conditions. Provide support for drug safety. When toxicologically relevant impurities are not readily available, toxicological evaluation of samples degraded to a certain extent can provide a supportive basis for drug safety and impurity limit determination. It is helpful for metabolite research. Some degradation products are also metabolites, and the metabolites produced by degrading test samples can be used for confirmatory studies and analysis. Contribute to the development of active pharmaceutical ingredient (API) technology, formulation process, and the screening of drug salt and crystal forms. When the degradation impurities have toxic structures, the production of impurities can be avoided by changing the process route. The process parameters can also be controlled to ensure that the impurities are at an acceptable level. The forced degradation results of different crystalline and salt forms of drugs can indicate their stability. Guide the development of drug packaging systems and determine storage conditions. Degradation test results can suggest drug susceptibility factors. The results of forced degradation testing, influencing factor testing, accelerated testing, and long-term testing together support drug packaging and storage conditions. Purpose of forced degradation test The purpose of the forced degradation study  is to understand the degradation products and degradation pathways of drugs under different destruction conditions. The forced degradation test can provide a useful reference for the establishment of analytical methods, the formulation of instructions and the determination of formulation design. Degradation pathways Aggregation Non-covalent aggregates are usually the result of mechanical stress (like shaking, stirring, rotating, pumping), and aggregation can also occur after repeated freezing and thawing, heating, or exposure to acidic pH environments. Aggregation can also be covalent in nature, such as chemical bonding between molecules, which are not dissociable during buffer exchange. These chemical bonds are usually formed by rearranged disulfide bonds or other altered intramolecular chemical linkages. They are usually the result of amino acid residues reacting with trace metals (copper or iron) or incomplete protein reduction. Oxidation The side chains of methionine, cysteine, histidine, tryptophan or tyrosine residues are prone to oxidation, with methionine being the most reactive residue. Oxidation can alter the physicochemical properties of proteins, such as folding and subunit association. Oxidative conditions are formed primarily by exposure to atmospheric oxygen, in the presence of light, heat, moisture, agitation or exposure to oxidants. Deamidation is the hydrolysis of asparagine or glutamine into free carboxylic acid residues, usually due to changes in pH, ionic strength, temperature and humidity of lyophilized proteins. The overall effect of chemical modifications to a single amino acid residue depends on its location in the protein and the specific role of the residue in the protein's functional and active site. Illumination photolysis by exposure to light involves and affects free radicals of many functional groups, such as carbonyl groups, which can lead to oxidation, aggregation, or cleavage of peptide bonds. Photolysis is caused by exposure to a certain amount of photoradiation, usually in the form of ultraviolet radiation. Hydrolysis Hydrolysis (cleavage) is the breaking of peptide bonds between amino acid residues, releasing smaller peptide chains. The peptide bonds of Asp-Pro and Asp-Gly are the most easily hydrolyzed. Hydrolysis is mainly caused by exposure to acidic or basic pH. CD Formulation  is a leading manufacturer of a large variety of excipients. Driven by the latest science and technology, it has grown to be a reliable source for the pharmaceutical industry, offering not only rich collection excipients but also a wide range of preformulation, formulation, analytical and custom pharmaceutical excipients services. Always at the forefront of innovation, CD Formulation aims to address the challenges arising from pharmaceutical formulation, and in a much broader sense, hopes to advance the global medical business. ... View more

The OLED inkjet printing uses solvents to melt OLED organic materials and subsequently prints materials on the surface of substrates to form R (red), G (green), and B (blue) organic light-emitting layers. ... View more

Photochromic materials will change color after being excited by a light source. Due to their unique physical, chemical properties and abundant types, they have a broad range of applications in many types of devices, including optical switches, optical data storage devices, energy-conserving coatings, eye-protection glasses, and privacy shields. ... View more

What would you say if someone told you that one of the best things you could eat with a nice glass of certain red wines would be a fatty burger? It wouldn’t hurt to try it with filet mignon, either, but there is something special about that burger that will probably surprise you. According to a report in ACS’ journal Langmuir, lipids (fats) in certain foods match up well with wines high in tannins (polyphenols, or antioxidants) to produce a smooth-tasting beverage. Such wines are Cabernet Sauvignon, Petite Sirah, Montepulciano, Tempranillo, Petit Verdot and Nebbiolo, all reds. This interaction is critical to the taste of the wine because the fats interfere with the tannins’ ability to mix with saliva and create a bitter taste, says Julie Géan, Ph.D., who is the study team leader. So any foods with a significant amount of lipids would work well with these high-tannin red wines. Studies have shown that tannins from red grape seeds and skins are known to play an important part in taste since they contribute to red wine astringency, a dry and rough sensation in the mouth. “Based on our study, we can assume that fats present in meat, fish and cheese could interact with tannins when you drink wine,” said Géan, who is with Université Bordeaux, Pessac, France. This study is unique because of its close examination of interactions between the tannins and the lipids and their effect on the wine taste and “feel,” she said. Researchers had studied astringency and the tannin-saliva interaction widely, but little was known about interactions between tannins and lipids and their implications for tasting wine. In addition, the influence of food on the flavor and dryness of wine is well known by consumers, but has not been examined at the molecular level, according to Géan. That is, we know that cheese goes well with a nice Petite Sirah, but we just haven’t known why –– until this study. So with what you now know, how about trying a glass of red with a double cheeseburger? Red Wine Tannins Fluidify and Precipitate Lipid Liposomes and Bicelles. A Role for Lipids in Wine Tasting? Click here for the abstract. *Journalists can request a PDF of the journal article by emailing newsroom@acs.org ... View more