Thermoset polymers Alkyd resins

Thermo set polymers Alkyd resins Amino resins Epoxy resins Phenolic resins Poly(bis maleimide) Polyesters, unsaturated Thermoset resin Tohprene TOR Torelina Torlon TP 301 TPX... 

This is a very broad class of compounds commonly used in coatings. Over 400-500 different alkyd resins are commercially available. They are polyesters containing unsaturation that can be cross-linked in the presence of an initiator known traditionally as a drier. A common example is the alkyd formed from phthalic anhydride and a glyceride of linolenic acid obtained from various plants. Cross-linking of the multiple bonds in the long unsaturated chain R produces the thermoset polymer by linking R groups of separate molecules with each other. 

Adipic acid [124-04-9] - [ALKYD RESINS] (Vol 2) - [DICARBOXYLIC ACIDS] (Vol 8) - [FOOD ADDITIVES] (Vol 11) - (ELECTROCHEMICALPROCESSDTG - ORGANIC] (Vol 9) -barrier polymers from [BARRIERPOLYMERS] (Vol 3) -from cyclohexane [HYDROCARBONS - C1-C6] (Vol 13) -from cyclohexane [HYDROCARBON OXIDATION] (Vol 13) -from cyclohexanol [CYCLOHEXANOL AND CYCLOHEXANONE] (Vol 7) -as food additive [FOOD ADDITIVES] (Vol 11) -nylon from [POLYAMIDES - FIBERS] (Vol 19) -nylon-6,6 from [POLYAMIDES - GENERAL] (Vol 19) -nylon-6,6 from [POLYAMIDES - PLASTICS] (Vol 19) -m polyester production [COMPOSITE MATERIALS - POLYMER-MATRIX - THERMOSETS] (Vol 7) -m polyester resins [POLYESTERS, UNSATURATED] (Vol 19) -soda preservatives [CARBONATED BEVERAGES] (Vol 5)... 

Phthalide (241) has been used as an additive used to prepare polyesters with low molten viscosity <91JAP(K)03200859>. Phthalic anhydride (242), prepared by the oxidation of o-xylene, is of major importance to the chemical industry with 1992 production over 400000 tonnes <93CEN38>. It is used as a monomer in the preparation of alkyd resins (a polyester with glycerol and other polyols) and thermosetting polymers (with maleic anhydride and polyols). Another important application is in the production of dioctyl phthalate (243), which is used as a plasticizer for PVC (1991 production, 123000 tonnes). Over 400 references pertaining to the use of phthalic anhydride in polymer compositions have appeared since 1982. Tetrabromophthalic anhydride (244) has been used to prepare flame-retardant bisphthalimides as polymer additives <90JAP(K)02145568>. 

Polyesters A broad class of polymers usually made by condensation of a diol with dicarboxylic acid or anhydride. Polyesters consist of chains with repeating carbonyloxy group and can be aliphatic or aromatic. There are thermosetting polyesters, such as alkyd resins and unsaturated polyesters, and thermoplastic polyesters such as PET. The properties, processing methods, and applications of polyesters vary widely. Also called Polyester Resins. 

This book focuses on bio-based plastics. It emphasizes materials that are presently in use or that show a significant potential for future applications. It presents a broad, up-to-date but concise overview of basic and applied aspects of bioplastics. The main focus is on thermoplastic polymers for material use. Elastomers, thermosets and coating applications, Uke, for example, natural rubber or alkyd resins, will be covered in other volumes of the series. 

The condensation reaction between carboxylic acid and alcohol to form an ester and water is a fundamental chemical reaction, and has been known at least from when the term organic chemistry was coined in the early nineteenth century. From the mid- to late-nineteenth century, studies were carried out on the reactions of compounds containing more than one acid group with compounds containing more than one hydroxyl group. These studies produced the first polyester resins, and lead to the development in the early twentieth century of various thermoset polymers such as the alkyd resins. 

The first fully synthetic polymer to be introduced (1909) was a phenol-formaldehyde resin known as bakelite. Although the reaction had been discovered some twenty years previously, it was only after a careful and systematic study of it that it was properly controlled to give a useful thermosetting resin. In the late 1920s two other types of thermosetting resins followed, namely urea-formaldehyde, and alkyd resins. 

Thermoset materials are produced by the direct formation of network polymers from monomers, or by crosslinking linear prepolymers. Important thermosets include alkyds, amino and phenolic resins, epoxies, unsaturated polyesters and polyurethanes. Thermosetting polymers consist of two liquid components, one containing a resin and the other a hardener [1]. 

Unsaturated low molecular weight (M between 1000 and 10000), often branched, used as macromonomers for synthesis of thermosets (polyester resins), or thermosetting materials by themselves (alkyd resins). They are prepared from several monomers, namely phthalic and maleic anhydrides, adipic acid, iso-phthalic acid, natural fatty acids or triglycerides, and a great variety of multifunctional alcohols. In a few special cases, they may be saturated and/or linear for use as macromonomers in the production of polyurethanes or other polymers. 

The most important alkyds are obtained from glycerol and phthalic anhydride. A linear polymer can be obtained by heating them at 180°C in ratio 2 3 (i.e., excess of acid). This polymer when heated forms cross-links and yields a thermosetting insoluble resin. 

Thermoset resins covers an extremely wide range, including phenol formaldehyde polymers, aminopolymers, PUs, epoxies, and thermoset polyesters, which include the alkyd and unsaturated vinyl ester resins. Of special interest at the present time are those that comprise the resin component of liber-reinforced composites that are finding increasing use in commercial and defense sectors, where fire resistance is of paramount importance. Typical resins used are those listed in Table 2.4 along with typical, respective LOI values in descending order of increased inherent fire resistance. 

Very little is known about the structure of the cured polyester resin. The products definitely belong in the thermoset class. There is some correlation between maximum physical properties a nd a molar ratio of 1 1 between double bonds in the alkyd and monomer. However, this is not critical and simple cross-linking does not tell the full story. The styrene monomer can be present in twice the molar amount needed, and yet complete copolymerization takes place without apparent formation of styrene polymer. 

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