Pentaerythritol, reaction + anhydrides

Alkyd resins are produced by reaction of a polybasic acid, such as phthaUc or maleic anhydride, with a polyhydric alcohol, such as glycerol, pentaerythritol, or glycol, in the presence of an oil or fatty acid. The resulting polymeric material can be further modified with other polymers and chemicals such as acryhcs, siUcones, and natural oils. On account of the broad selection of various polybasic acids, polyhydric alcohols, oils and fatty acids, and other modifying ingredients, many different types of alkyd resins can be produced that have a wide range of coating properties (see Alkyd resins). 

Soya oil, 88.6 g, 20.0 g of pentaerythritol, and 0.06 g of lithium hydroxide monohydrate are weighed into a 250-mL three-necked round-bottom flask fitted with a magnetic stirrer, a Dean-Stark separator, and nitrogen inlet and outlet. The reaction mixture is heated to 250°C for 30 min under nitrogen (note a below), then cooled to 200°C. Phthalic anhydride, 34.6 g, 0.70 g of maleic anhydride, and 8.0 g of xylene are added. The reaction mixture is heated to 230°C and the toluene-water azeotrope is removed by distillation. The reaction is stopped when the acid number of reaction medium is lower than 10 (note b below). After cooling to room temperature, 52 g of white spirit is added. 

By depolymerizing PET waste with a polyol and subsequently condensing the oligomeric product with a polycarboxylic acid or anhydride, polyester resins are produced which have wide industrial applications. Depending on the polyol and polycarboxylic acid or anhydride used, saturated resins, alkyd resins, or unsaturated resins are obtained. PET wastes have been used for the production of alkyd resins in water thinnable paints. The materials obtained from the reaction of PET with a mixture of fatty acids high in linoleic acid content and trimethylolethane have been used in the preparation of water-dispersible coatings. Products of the depolymerization of PET with trimethylolpropane and pentaerythritol are used in the manufacture of high-solids paints. In the first step, PET is depolymerized with trimethylopropane and pentaerythritol at temperatures of 230-240°C. The final paint compositions contain 30-50% of PET depolymerization products.12... 

Ethyl alcohol has been made by the hydration of ethylene (9) since 1930. Like isopropyl alcohol, part of the output is used as a solvent, but most is converted to other oxygenated chemicals. Its most important raw material use is conversion to acetaldehyde by catalytic air oxidation. Acetaldehyde, in turn, is the raw material source of acetic acid, acetic anhydride, pentaerythritol, synthetic n-butyl alcohol (via aldol condensation), butyraldehyde, and other products. Butyraldehyde is the source of butyric acid, polyvinyl butyral resin, and 2-ethylhexanol (octyl alcohol). The last-named eight-carbon alcohol is based on the aldol condensation of butyraldehyde and is used to make the important plasticizer di-2-ethylhexyl phthalate. A few examples of the important reactions of acetaldehyde are as follows ... 

Monobromopentaerythritol, BrCH2C(CH20H)3, and its Trinitrate, BrCH2.C(CH20N02)3, crysts, mp 91°, These derivs were prepd by reaction of pentaerythritol with hydrobromic acid in the presence of acetic anhydride, followed by nitration with HNOj. Elrick et al (Ref 2) earlier prepd lAonobromopentaerythritol trinitrate, wh crysts (from ale), mp 89-90°, by nitrating the dinitrodefiv with 100% white HNOj... 

The synthesis of alkyd resins using vegetable oils proceeds in two stages. For example, pentaerythritol, the tetraol of choice and mainly responsible for the degree of branching of the alkyd [64], and a vegetable oil are reacted to form an ester by transesterification. Then, a slight excess of phthalic anhydride is added to obtain a crosslinked alkyd resin (Fig. 3.21) [65]. Both reactions are monitored by acidity and viscosity measurements [66]. 

The deviation of the observed extent of reaction of the gel point (/ A)exp for a given initial monomer concentration from the value calculated from Equation (17-68) is a measure of the tendency to cyclize. According to Figure 17-8 this tendency to cyclize is greater for phthalic anhydride than for isophthalic acid, and greater for pentaerythritol than for trimethylol propane. 

The dicarboxylic acids normally employed are phthalic acid or its anhydride, or mixtures of them with, for example, adipic acid or unsaturated acids. The polyhydroxy compounds generally used are glycerol, trimethylolpropane, or pentaerythritol. In the preparation and crosslinking of alkyd resins (with the exception of some unsaturated alkyd resins) the reaction is practically always carried out in the melt, taking the precautions discussed in Sect. 4.1. 

Another early material, still in wide use, that formed polymer networks, was the alkyd resins. The alkyds are a group of resins which can be called oil-modified polyesters. These polymers are formed through the condensation and exchange reactions among polybasic acids, polyhydric alcohols, and fatty monobasic acids. Typical polybasic acids are phthalic acid anhydride, maleic anhydride, etc. The polyhydric alcohol may be glycerin, pentaerythritol, etc., while the fatty acids may originate in soy bean or linseed oil. A typical alkyd has the following structure ... 

UVA 2-hydroxy-4-octyloxybenzophenone 2-hydroxy-4-methoxybenzophenone 2-(2H-benzotriazol-2-yl)-p-cresol 2-(2H-benzotriazole-2-yl)-4,6-di-tert-pentylphenol 2-(2H-benzotriazole-2-yl)-4-(1,1,3,3-tetraethylbutyl)phenol 2,4-di-tert-butyl-6-(5-chloro-2H-benzotriazole-2-yl)-phenol 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl]-5-(octyloxy) phenol ethyl-2-cyano-3,3-diphenylacrylate HAS 1,3,5-tri-azine-2,4,6-triamine, N,N [1,2-ethane-diyl-bis[[[4,6-bis[butyl-(1,2,6,6-pentamethyl-4-piperidinyl)amino]-1,3,5-triazine-2-yl] imino]-3,1 -propanediyi] bis[N ,N -dibutyl-N ,N -bis(1,2,2,6,6-pentamethyl-4-piperidinyl)- bis(2,2,6,6-tetramethyl-4-piper-idyl) sebacate 2,2,6,6-tetramethyl-4-piperidinyl stearate N,N -bisformyl-N,N -bis-(2,2,6,6-tetramethyl-4-piperidinyl)-hexamethylendiamine alkenes, C20-24-.alpha.-, polymers with maleic anhydride, reaction products with 2,2,6,6-tet-ramethyl-4-piperidinamine 1,6-hexanediamine, N, N -bis(2,2,6,6-tetramethyl-4-piperidinyl)-, polymers with 2,4-di-ohloro-6-(4-morpholinyl)-1,3,5-triazine 1,6-hexanediamine, N,N -bis(2,2,6,6-tetramethyl-4-piperidinyl)-, polymers with morpholine-2,4,6-trichloro-1,3,5-triazine reaction products, methylated Phenolic antioxidants ethylene-bis(oxyethylene)-bis(3-(5-tert-butyl-4-hydroxy-m-tolyl)-propionate) 2,6,-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5,-triazine-2-ylamino) phenol pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate) 2-(1,1 -dimethylethyl)-6-[[3-(1,1 -dimethylethyl)-2-hydroxy-5-methylphenyl] methyl-4-methylphenyl acrylate isotridecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate 2,2 -ethylidenebis (4,6-di-tert-butylphenol) 2,2 -methylenebis(4-ethyl-6-tertbutylphenol) 3,5-bis(1,1-dimethyethyl)-4-hydroxy-benzenepropanoic acid, C13-15 alkyl esters phenol, 4-methyl-, reaction products with dicyclopen-tadiene and isobutene Phosphite trinonylphenol phosphite isodecyl diphenyl phosphite... 

A molar ratio of pentaerythritol to acetic anhydride from 1 1.37 to 1 3.5 and a temperature in the range of 100-150 °C were found to be the best reaction conditions for the synthesis of pentaerythritol diacetate. UP resins based on acetylated derivatives of pentaerythritol diacetate were obtained in the presence of a small amount of o-xylene at 140-150 °C with p-toluenesulfonic acid as the catalyst, under dry conditions. It was found that pentaerythritol diacetate also contained free pentaerythritol and pentaerythritol monoacetate, which caused a premature crossUnking of the synthesized resin. Thus, ethylene glycol and diethylene glycol were used in the synthesis of the UPR together with pentaerythritol diacetate. 

---