Unsaturated resins, high viscosity

Increase viscosity, e.g. magnesium oxide in unsaturated polyester resins increases the viscosity so much that a liquid resin becomes a tackfree solid, suitable for making sheet moulding compound (SMC). A relatively high viscosity is also desirable for latex compounds used to coat textiles. 

Epoxy vinyl ester resins are a special class of unsaturated resin. This resin is made by capping an epoxy resin with methacrylic acid and then dissolving in styrene monomer to the desired viscosity. This gives mechanical properties similar to epoxy resins, but the processibility (low viscosity allowing for resin infusion processes) of an unsaturated polyester resin. As with unsaturated vinyl esters, the most common fire retardant vinyl ester resin is based on a resin made from a halogenated system, tetrabromobisphenol A. The level of bromine in the resin and the presence of antimony will determine the fire performance of the resin. These resins are normally used for corrosion resistant equipment or when fire performance and high mechanical properties are required. It is very difficult to get a low smoke value with a brominated vinyl ester resin again due to the fact that bromine... 

The experimental unsaturated polyester resins used in this study were supplied by several chemical companies since the PET chemical conversion into unsaturated polyester could not be done at the University of Texas laboratories. These resins were prepolymers with high viscosity. They were therefore diluted with styrene to reduce their viscosity and allow their further cure to a solid (polymer) upon the addition of suitable free radical initiators and promoters. The typical styrene content varied between 30 to 40% of the total resin weight, and viscosities were in the range of 100 to 1000 cps. 

P.R.149 also lends color to cast resins made from materials such as unsaturated polyester or methacrylic acid methylester, which are polymerized with peroxide catalysts. P.R.149 is equally lightfast in these media. In polycarbonate, the pigment tolerates exposure to more than 320°C. This is an asset in view of the fact that polycarbonate shows high melt viscosity and is thus processed at up to 340°C. The list of applications also includes other media, such as PUR foams and elastomers, for which P.R.149 is recommended because of its good heat stability and its coloristic properties. 

Another resin application based on the same hyperbranched polyester structure described herein is low-VOC alkyds, which have very low viscosity and high reactivity compared to conventional high-solid alkyds. Other resin structures are unsaturated polyesters, polyurethane dispersions, and epoxides. ... 

Bellstein Handbook Reference) AI3-08678 BRN 0878263 CCRIS 876 DImethoxymethyl-phosphIne oxide Dimethyl methanephosphonate Di-methyl methylphosphonate DMMP EINECS 212-062-3 Fyrol DMMP HSDB 2590 Methyl phosphonic acid, dimethyl ester NCI-C54762 NSC 62240 Phosphonic add, methyl-, dimethyl ester Pyrol dmmp. Flame retardant for applications where high phosphorus content, good solvency, and low viscosity are desired lowers viscosity of epoxy resins and unsaturated polyesters filled with hydrated alumina oxide. Liquid bp = 181 , bp20 = 79.6" d ° = 1.4099 Am = 217 nm (e = 13, EtOH) soluble in H2O, Et20, EtOH LDsO (rat orl) > 5000 mg/kg. Akzo Chemie. 

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