PMMA+acetone

PMMA bulk PMMA/ chloroform PMMA/ toluene PMMA/ acetone PMMA/ THF... 

Acrylics. Acetone is converted via the intermediate acetone cyanohydrin to the monomer methyl methacrylate (MMA) [80-62-6]. The MMA is polymerized to poly(methyl methacrylate) (PMMA) to make the familiar clear acryUc sheet. PMMA is also used in mol ding and extmsion powders. Hydrolysis of acetone cyanohydrin gives methacrylic acid (MAA), a monomer which goes direcdy into acryUc latexes, carboxylated styrene—butadiene polymers, or ethylene—MAA ionomers. As part of the methacrylic stmcture, acetone is found in the following major end use products acryUc sheet mol ding resins, impact modifiers and processing aids, acryUc film, ABS and polyester resin modifiers, surface coatings, acryUc lacquers, emulsion polymers, petroleum chemicals, and various copolymers (see METHACRYLIC ACID AND DERIVATIVES METHACRYLIC POLYMERS). 

Crystalline samples of syndiotactic poly(methyl methacrylate) (st-PMMA) may be obtained from chloroacetone 178). This guest could be completely replaced by a variety of other guest molecules such as acetone, 1,3-dichloroacetone, bromoacetone, pinacolone, cyclohexanone, acetophenone and benzene. The X-ray diffraction patterns for these inclusion compounds were similar. These data indicate that the st-PMMA chains adopt a helical conformation of radius about 8 A and pitch 8.85 A. The guest molecules are located both inside the helical canals and in interhelix interstitial sites. 

Reaction of K3Co(CN) with PMMA. A 1.0 g sample of PMMA and 1.0g of the cobalt compound were combined in a standard vessel and pyrolyzed for 2 hrs at 375°C. The tube was removed from the oven and the contents of the tube were observed to be solid (PMMA is liquid at this temperature). The tube was reattached to the vacuum line via the break-seal and opened. Gases were determined by pressure-volume-temperature measurements on the vacuum line and identified by infrared spectroscopy. Recovered were 0.22g of methyl methacrylate and 0.11 g of CO and C02. The tube was then removed from the vacuum line and acetone was added. Filtration gave two fractions, 1.27g of acetone insoluble material and 0.30g of acetone soluble (some soluble material is always lost in the recovery process). The acetone insoluble fraction was then slurried with water, 0.11 g of material was insoluble in water. Infrared analysis of this insoluble material show both C-H and C-0 vibrations and are classified as char based upon infrared spectroscopy. Reactions were also performed at lower temperature, even at 260°C some char is evident in the insoluble fraction. 

Reaction of HCofPfOPh), with PMMA. A 1.0g sample of PMMA and 1.0g of the cobalt compound were combined as above. After pyrolysis at 375°C for two hours the tube is noted to contain char extending over the length of the tube with a small amount of liquid present. The gases were found to contain CO, C02, hydrocarbon (probably methane), and 0.1 Og methyl methacrylate. Upon addition of acetone, 1.0g of soluble material and 0.19g of insoluble may be recovered. The infrared spectrum of the insoluble fraction is typical of char. 

There is a compelling reason to integrate PMMA and phenol-formaldehyde because the monomers phenol and acetone are both made from cumene oxidation (previous chapter). Therefore, one makes one mole of phenol for every mole of acetone, and a producer would have to sell one of these monomers if he did not have an integrated process to produce both polymers or some other products. 

Fig. 21 Topographic AFM images of PMMA/PS-mixed homopolymer brushes with different ratios of (Tpmma and aps but nearly equal opmma + <7ps 0-5 chains nm ) after treatment with acetone, where

Fig. 2. a. Intensity correlation of the scattered light from a PMMA sample in acetone recorded with a Malvern autocorrelator with 96 channels. At channel 80, a time shift device is introduced, by which the last 12 channels are shifted by 256 times the delay time of the first channel. These last channels were used for a determination of the base line, b Plot of In (G2 - 1 )m against the channel number (= time) for the same sample as in a. The deviation from the straight line arises from the internal flexibility of the PMMA chain... 

PMMA-PS-PMMA M = 316 Butanone, toluene (neutral) Acetone (selective for PMMA) Triethyl benzene (selective for PS)... 

There has been no report of oriented crystalline syndiotactic PMMA so far as the author knows. The author and his coworkers (39) found that oriented crystalline samples of syndiotactic PMMA can be obtained by adsorption of various solvents such as chloro-acetone and diethyl ketone. Figure 8 shows the x-ray diagrams. When the polymer is cast from chloroform solution and is stretched in hot water at 80°C, the sample is noncrystalline as shown in Figure 8. By adsorption of the solvent the fiber diagram can be... 

Poly (methyl methacrylate) (PMMA) CDC13, CD2CI2, CD3CN, acetone, C6D6, EtOAc 104... 

In the case of PMMA dissolved in acetone, the change of LSI could be correlated both with the separation of fragments and, to some extent, with the lifetime of the intermediates which contribute to the main-chain scission [71]. The LSI decreased in two modes, probably due to the two pathways for the main-chain scission. The fast mode with a lifetime of about 20 ps was influenced neither in its extent nor in its rate by the addition of 02 or mercaptane. Therefore the first mode was ascribed to the diffusional separation of fragments which are generated by the main-chain scission through the direct decomposition of electronically excited or ionic intermediates. The slow mode with a lifetime of 6 ms was suppressed, to an extent, depending on the ( -concentration it was attributed to long-lived polymer radicals. The added 02 reacts with lateral polymer radicals to prevent their decomposition. 

More recently, this method has been successfully extended by us18 to form the inverse systems, i.e. water core/polymer shell particles dispersed, initially in oil, but then transferred to an aqueous continuous phase. Clearly, whether one needs an oil or a water core depends on the nature of the active material to be released. Now one starts with a water/oil emulsion, rather than an oil/water emulsion, but the basic principles are very similar. A variety of shell polymer systems were prepared, including PMMA and poly(tetrahydrofuran) [PTHF]. The high vapor pressure liquid used in this case was in general, acetone. It turned out, however, that these water core systems are intrinsically more difficult to make than the equivalent oil core systems, because large amounts of acetone were required to dissolve the polymers initially in the water-acetone mixtures. An oil was then required which did not mix too well with acetone. In general, mineral oil worked reasonably well. In order to transfer the water core capsules into an aqueous continuous phase, the particles were centrifuged in... 

Fig. 9. Correlation plots of (the time corresponding to the inflection point on the differential two-stage curve) and Ct° (the initial concentration of each differential absorption) O PMMA-methyl acetate (30° C). APSt-benzene (25° C). IPSt-LC-benzene (35° C). IPSt-HC-benzene (35° C). cellulose acetate-methyl acetate (20° C). g cellulose nitrate-acetone (25° C). A regenerated cellulose-water (15° C). PMMA = polymethyl methacrylate. APSt = atactic polystyrene. IPSt-LC = isotactic polystyrene of low crystallinity. IPSt-HC = isotactic polystyrene of high crystallinity. Taken from Fujita, Kishimoto and Odani...

Fig. 33a-d. Solvent effect on the formation of the stereocomplex of isotactic polyfmethyl methacrylate) (iso-PMMA) with syndiotactic PMMA (synd-PMMA)300. (a) In chloroform, (b) in benzene, (c) in dimethylformamide, (d) in acetone... 

In another study Slobodian et al. (57) found that the percolation threshold for electrical conductivity of MWCNT-PMMA composites depends on the solvent used. The lowest percolation threshold was achieved for toluene where percolation was found to be at 4 wt% of MWCNT, for chloroform at 7 wt% and for acetone at 10 wt%. The highest conductivity was obtained at 20 wt% of MWCNT at values around 4x 10 5 Sc nr1 for composite prepared from toluene solution. They observed that the Hansen solubility parameters of individual solvent play an important role in the dispersion of MWCNT in PMMA. 

Shang et al. 2009 (61) MWCNT Purified Microemulsion polymerization CNT Loading levels 1 tol5wt% MWCNT-PMMA composites prepared by microemulsion polymerization at 8 wt% loading showed high sensor responses to different organic vapors such as acetone, toluene, THF, choloroform, acetonitrile, benzene They suggested the use of these composites for gas sensor applications ... 

---