The functions about Eudragit

Eudragit is a Methacrylate-based coating materials with a variety of functional properties.

Functionality  Anionic polymer of methacrylic acid and methacrylates with a -COOH group Eudragit L 100-55 - powder, spray dried L 30 D-55 which can be reconstituted for targeted delivery in the duodenum. Eudragit L 30 D-55 - aqueous dispersion, pH dependent polymer soluble above pH 5.5 for targeted delivery in the duodenum. Eudragit powder, pH dependent polymer soluble above pH 6.0 for targeted delivery in the jejunum. Eudragit powder, pH dependent polymer soluble above pH 7.0 for targeted delivery in the ileum. Eudragit FS 30 D - aqueous dispersion, pH dependent polymer soluble above pH 7.0, requires no plasticizer. Cationic polymer with a dimethylaminoethyl ammonium group Eudragit E 100 - granules, pH dependent, soluble in gastric fluid up to 5.0, swellable and permeable above pH 5.0.  Eudragit E PO - powder form of E-100, Copolymers of acrylate and methacrylates with quarternary ammonium group. Insoluble, High Permeability . Eudragit RL 30D - aqueous dispersion, pH independent polymer for sustained release formulations.

 Eudragit RL PO - powder, pH independent polymer for matrix formulations. Eudragit RL 100 - granules, pH independent. Eudragit is mainly used as tablets, pills, granules,film-forming agent for enteric-type coating material and enteric capsule shell, microcapsules film agent,it is also used for the coating materials and reinforcing materials of sustained-release formulations.

Readmore: Eudragit online

Reprint: http://www.chem-pharma.net/blog/view.asp?id=3

The medical uses about Methoxsalen

Methoxsalen  is used along with controlled ultraviolet light (UVA) to cause a return in skin color in patients with a certain skin condition (vitiligo). Methoxsalen works by making the skin more sensitive to UVA light. This combination helps to increase the number of pigment-producing cells (melanocytes) in the skin.

Methoxsalen  is a drug used to treat psoriasis, eczema, vitiligo, and some cutaneous Lymphomas in conjunction with exposing the skin to sunlight. Methoxsalen is extracted from Ammi majus, a plant of the family Apiaceae. Methoxsalen modifies the way skin cells receive the UVA radiation, allegedly clearing up the disease. The dosage comes in 10 mg tablets, which are taken in the amount of 30 mg 75 minutes before a PUVA (psoralen + UVA) light treatment. The substance is also present in other Apiaceae as well as Rutaceae, for example bergamot oil which is used in many perfumes and aromatherapy oils.

Methoxsalen  is a naturally occurring substance that is reactive to light. It works by enhancing the body's sensitivity to ultraviolet light A (UVA). Methoxsalen is used in combination with UVA light therapy to treat severe psoriasis. Methoxsalen is usually given after other psoriasis medications have been tried without successful treatment of symptoms.

However, Patients with high blood pressure or a history of liver problems are at risk for inflammation and irreparable damage to both liver and skin. The eyes must be protected from UVA radiation. Side effects include nausea, headaches, dizziness, and in rare cases insomnia. Methoxsalen has also been classified as an IARC Group 1 carcinogen (known to cause cancer) but is only cancerous when combined with Ultra Violet-A radiation.

Readmore: Methoxsalen  online

Reprint: http://www.biomedicine-pro.net/blog/view.asp?id=12

The basic properties about HONB

Name:HONB
CAS NO. 21715-90-2
EINECS NO. 244-538-6
FORMULA C9H9NO3
MOL WT. 179.18
SYNONYMS HONB; endo-n-Hydroxy-5-norbornene-2,3-dicarboximide;  n-Hydroxy-5-norbornene-2,3-dicarboximide;  N-Hydroxybicyclo[2.2.1]hept-5-ene- 2,3-dicarboximide; 4,7-Methano-1H-isoindole-1,3(2H)-dione, 3a,4,7,7a- tetrahydro-2-hydroxy-; N-Hydroxy-5-norbornene-2,3-dicarboximide; 
PHYSICAL STATE HONB is white crystals
MELTING POINT  165 - 170 C   
SOLUBILITY IN WATER Soluble
STABILITY Stable under ordinary conditions.
We can supply the best HONB, please contact us.
Readmore: HONB online
Reprint: http://www.chemical-chem.com/blog/view.asp?id=10

The homopolymer live hydrolysis

Homopolymer site hydrolysis process is divided into two parts, the first non-ionic PAM homopolymerization process to produce non-ionic PAM powder; then use the on-site construction hydrolysis device will produce dry powder dissolved, then add sodium hydroxide hydrolysis get the anionic PAM aqueous solution. Redispersible latex powder

Before adding alkali hydrolysis polymerization process

Before adding alkali hydrolysis process multiple complex low-temperature initiator system, and add a degree of polymerization of functional monomers and to improve the solubility of high molecular weight polymer cosolvent in the polymerization process. Polymerization, the polymerization of the polymer gel by cutting, granulation, drying, screening processing powdered poor child quality anionic polyacrylamide product in the kettle or tank reactor. The process is the production of PAM products, relative molecular mass of 19 million.

Homopolymer hydrolysis process

Are poly Hydrolysis process is the first non-ionic PAM homopolymer into the granulation after sodium hydroxide hydrolysis, and finally by drying powdered PAM products. Redispersible latex powder

The composite catalyst system in the process, ie oxidation of the reductant and the thermal decomposition catalyst compound, oxidation of the reducing agent from the role of polymerization reaction, the reaction is essentially an adiabatic process. Colloid by the end of the polymerization after cutting anyone to hydrolysis, high temperature alkali spray to rubber or directly adding alkali particles, and maintain the hydrolysis temperature at 80 ℃. After the hydrolysis process to produce polymer relative molecular mass of about 20 million, but the molecular weight distribution of a wide, high production costs.

Read  More:PAM powder (non-ion) sales

The Origin of Neutral polyester sizing agent

Sizing papermaking process, the degree of sizing is an important physical indicators indicate the quality of paper or paperboard, and the sizing process is to use the strong hydrophobic material covering the surface of the paper fibers to form a layer of hydrophobic filmreduces the fiber surface free energy, in order to resist the diffusion of water or other liquids on the fiber surface, wetting or penetration, and with this performance material called sizing agent.

The earliest material as a sizing agent is a natural rosin, since the discovery in 1807, it was used nearly 200 years, is still used, just through a variety of methods were modified, conventional sizing acidic sizing, sizing process must make use of aluminum sulfate as a retention agent, rosin acid with negative charge retention in the fiber, to achieve the purpose of sizing, though later on the rosin was modified, prepared maleic rosin saponification gum, fumaric acid rosin, acrylic rosin sizing effect greatly improved, but still must be carried out under acidic conditions sizing.

Many shortcomings due to the acidic sizing, so attention has turned to neutral sizing, 1956, the successful development of synthetic sizing agent of AKD, invented in 1968, ASA synthetic sizing agent, because of the sizing agent of the class applied for reactive glue, can and fiber reaction, keep their own, and thus do not need the help of aluminum sulfate, sizing in high PH value, neutral or alkaline sizing.

Read More：Neutral Sizing Agent Sales

Cationic rosin sizing agent Review（一）

Domestic cationic rosin sizing agent there are three kinds of methods: cationic method, the cationic emulsion method and the transformation method.

Cationic law

Itself cationic use the reaction of the carboxyl or small monomer rosin and unsaturated cationic copolymer introduced in the rosin molecule cationic achieve cationic, namely through the rosin itself to the formation of the cation, then add the cationic or non-ionic surfactant agent rosin emulsified and dispersed, some cationic rosin itself is a surface active agent can be directly on the rosin emulsified and dispersed to obtain high dispersion glue. The formation of cation resin such as rosin and unsaturated quaternary ammonium salts by the Diels-Alder reaction. Unsaturated monomer and rosin acid copolymer ene Class C trimethyl ammonium chloride, allyl butyl trimethyl ammonium chloride, dimethyl (dimethylamino) ethyl acrylate and so on. The cationic rosin, synthetic methods:  abietic acid with epichlorohydrin reaction and generate intermediates and then further reacted with amines to the formation of quaternary ammonium salts can also be as rosin Mr. glycidyl, and then amination quarter post-ammonium quaternary ammonium salt; rosin acid is first formed with diethylene triamine  amide, and then dimethyl sulfate quaternized; rosin amine reaction with ethylene oxide generated rosin acid polyoxyethylene ether, quaternary ammonium salt with chlorine methylamines .
Cationic rosin sizing material is generally difficult to emulsify, to select the appropriate emulsifier, emulsifying temperature and time conditions. Studies have shown that certain amount according to the method  the synthesis of their own cationic rosin material, respectively, under mechanical stirring the water with the temperature, mass fraction of 0.1% peregal -15 aqueous solution, 0.1% OP-10 aqueous solution 0.1% TX-10 solution dubbed a certain concentration of latex, rubber latex interface migration rate determined by electrophoresis, the calculation of the zeta potential of 30 mV, more than the product of the U.S. Hercules .

Read More:Cation-Rosin-Sizing-Agent sales

Effects of Fatty Acid Components Present in AKD Wax on Emulsion Stability and Paper Sizing Performance

abstract

  Commercial alkyl ketene dimer (AKD) waxes generally contain 80-90% AKD and the rest of the components are by-products, such as fatty acids, acid anhydrides, and AKD oligomers. 

In this paper the effects of fatty acid components present in AKD waxes

 on AKD emulsion stability and paper sizing performance were using AKD 

emulsions prepared from a mixed AKD wax with 0-12% stearic acid and palmitic acid. Repeated thermal-shock treatments revealed that the fatty acids-containing AKD emulsions unstable at 3% fatty acid content was, while those

 with 12% fatty acids were quite stable. When the addition of fatty acids was increased 

up to 12%, increased zeta potentials of the AKD emulsion particles of 1.4 mV to 4.4 mV 

with increasing fatty acids. This increase of the zeta potential can be one of the factors that 

will lead to a decrease in AKD retention ratios in broadsheets. Thus reducing fatty acid

 components in AKD waxes not only the pure AKD content present in the growth, 

but also have negative effects on the emulsion stability and paper sizing performance. 

These results indicate that fatty acids in AKD waxes are regulated sufficiently kept 

as low as possible to a standard level of AKD wax to maintain quality.

Read More:AKD Wax  sales