Acrylic Acid and Acrylates

Acrylic Acid and Acrylates. Acrylic acid and acrylates may be produced commercially by the Reppe reaction of acetylene.76,184-187 However, the industrial significance of these processes has diminished since acetylene is no longer a viable source and was replaced by ethylene. Acrylic acid and acrylates are now produced by propylene oxidation (see Section 9.5.2). 

The industrial catalytic Reppe process is usually applied in the production of acrylic acid. The catalyst is NiBr2 promoted by copper halides used under forcing conditions. The BASF process, for example, is operated at 225°C and 100 atm in tetrahydrofuran solvent.188 Careful control of reaction conditions is required to avoid the formation of propionic acid, the main byproduct, which is difficult to separate. Small amounts of acetaldehyde are also formed. Acrylates can be produced by the stoichiometric process [Eq. (7.20)], which is run under milder conditions (30-50°C, 1-7 atm). The byproduct NiCl2 is recycled  

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COLUMN SELECTION AND RELATED ISSUES FOR ACRYLIC ACID AND ACRYLATE ESTER POLYMERS... 

Acrylonitrile, acrylic acid, and acrylates...they all sound alike the, molecules in Figure 19—1 look similar, they are all...covered in this same chapter. So they must be well connected. Right ... 

The syntheses of carboxylic acids and esters are widely studied processes. Since the first examples of carboxylation in the presence of metal carbonyls were reported by Reppe, these reactions are sometimes referred to as the Reppe reactions. In his pioneering work125-127 stoichiometric or catalytic amounts of [Ni(CO)4] and ethylene or acetylene were reacted in the presence of water or alcohols to form saturated and unsaturated acids and esters. Commercial processes are practiced in the manufacture of propionic acid, acrylic acid and acrylates (see Section 7.2.4). 

A solution contains 63 different conjugate acid-base pairs. Among them is acrylic acid and acrylate ion, with the equilibrium ratio [acrylate]/[acrylic acid] = 0.75. What is the pH of the solution ... 

Hydroxybenzaldehydes and 2-hydroxy-l-naphthaldehydes react under Baylis-Hillman conditions with various activated alkenes to yield 3-substituted 2//-chromene derivatives (Equation 35) <2002J(P1)1318>. 2-Hydroxybenzaldehyde also reacts with acrylic acid and acrylic esters under Baylis-Hillman conditions to afford 3-carboxylatc-2//-chromenes in high yield <2001SC1233>. 

South Africa. Sasol produces many products from coal-derived syngas, including ethylene, propylene, a-olefins, alcohols, and ketones. They have also increased their production of methanol, synthetic lubricants, detergent alcohols, acrylic acid and acrylates, oxo-alcohols, styrene and polystyrene, propylene oxide, and propylene glycol. 

Many monomers can be grafted by redox polymerization to the magnetic core [magnetic material embedded in poly(vinyl alcohol) matrix nominally 100% cross-linked with glutaraldehyde] to get whisker-type resins " . Acrylic acid and acryl-... 

In ASA terpolymer acrylic acid brings more flexibility and the material has very good mechanical properties and weather resistance. For these reasons ASA is extensively used in automotive industry and in the fabrication of various appliances. Even more frequently than acrylic acid itself, various acrylates are used in copolymers. Among these can be mentioned the copolymers of acrylic acid esters with methacrylic acid esters such as poly(methyl methacrylate-co-methyl acrylate), poly(methyl methacrylate-co-ethyl acrylate), poly(methyl methacrylate-co-butyl acrylate), poly(ethyl methacrylate-co-ethyl acrylate), poly(acrylonitrile-co-methyl acrylate), poly(alkyl acrylate-co-methyl methacrylates), and poly(alkyl acrylate-co-hydroxyethyl methacrylates) where alkyl can be methyl, ethyl, butyl, etc. Some literature information regarding thermal decomposition of copolymers including acrylic acid and acrylic acid esters is given in Table 6.7.8 [6],... 

Table 6.7.8. Summary regarding literature information on thermal decomposition of copolymers including acrylic acid and acrylic acid esters.

Growth in the traditional coating and textile applications of acrylic acid and acrylates is being extended by the use of polyacrylic acid as an absorbent (in diapers ) demand now exceeds 500 kilotonnes per annum in the U.S. and 250 kilotonnes per annum in western Europe. 

Some related reactions of commercial importance, alkyne carbonylation to acrylic acid and acrylic esters, are discussed in Chapter 12. 

Figure 13.1 Typical monomers of acrylic acid and acrylic esters.

The necessary temperatures and pressures of the carbonylation reactions are largely determined by the unsaturated starting material and the catalysts applied. In the pressureless stoichiometric carbonylation of acetylenes with Ni(CO)4, temperatures of 35 to 80 are sufficient. In the catalytic procedure with Ni(CO)4 temperatures of 120 to 220 °C and pressures around 30 atm are normally applied. In special cases lower temperatures may be used, e. g. in the acrylic acid and acrylic acid ester syntheses, which... 

The block copolymer of acrylic acid and acrylic acid stearyl is an example of crosslink formation via van der Waals forces. The side chain stearic... 

A first detailed investigation of a spray polymerization process is done by Kruger in 2003 [8]. He polymerizes acrylic acid and acrylates in drops falling through a heated tower. Due to the low residence time in a spray dryer the process requires a very intensive reaction with fast reaction kinetics, see Fig. 20.2. Acrylic acid and its acrylates polymerize in a free-radical reaction and is chosen by Kruger and in this... 

In Fig. 20.14 (left) it is shown that the curves of acrylic acid start with a short plateau, where the viscosity stays constant, which is due to the induction period r. After the plateau the viscosity is increasing drastically. The first result that is analyzed is the induction period or time of the plateau. A procedure is used that compares the relative deviations of viscosity between the following data and if a threshold of 2 % is exceeded the inhibition will be completed and an induction period r of acrylic acid and acrylate is determined. 

Based on this concept, various combinations of M and Me monomers were explored. As Me monomers, various lactones, (meth)acrylic acid, and acrylates were often employed. Oxazolines were widely used as reactive M monomers. An... 

Another factor which can affect the soluble fraction is the relative reactivities of acrylic acid or sodium acrylate with the crosslinkers. As evidenced by reactivity ratios of various monomer pairs, methacrylate esters tend to be more reactive with acrylic acid and acrylate esters less reactive with acrylic acid. In a crosslinking copolymerization therefore, a methacrylate crosslinker will tend to be used up earlier in the reaction than will an acrylate crosslinker. As a result, use of methacrylate crosslinkers tends to give crosslinked polyacrylates with higher extractable fraction. 

Acetylene once was the raw material for commercial production of acrylic acid and esters, but in 1970 production of acrylic acid by oxidation of propylene was first practiced commercially. In a few years, the new process had essentially replaced the old. In 1988 about 3 percent (600 million lb) of the propylene used as a raw material for chemicals was converted to acrylic acid and acrylates. 

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