Styrene ethyl acrylate

A number of thermosetting acrylic resins for use as surface coatings have appeared during recent years. These are generally complex copolymers and terpolymers such as a styrene-ethyl acrylate-alkoxy methyl acrylamide... 

Applications Radiotracer measurements, which combine high sensitivity and specificity with poor spatial resolution, have been used for migration testing. For example, studies have been made on HDPE, PP and HIPS to determine effects of manufacturing conditions on migration of AOs from plastic products into a test fat [443]. Labelled antioxidant was determined radio-analytically after 10 days at 40 °C. Acosta and Sas-tre [444] have used radioactive tracer methods for the determination of styrene ethyl acrylate in a styrene ethyl acrylate copolymer. 

The alkenylation protocol between styrene, ethyl acrylate or acrylonitrile, and 5-bromo- and 5-iodo-pyrimidine gives the coupling product (882) (79CPB193, 81H(16)965>. Formation of 4,4 -bipyrimidines (884) is a major pathway from 4-iodopyrimidines (883) under the relatively vigorous conditions... 

This study of the chemical composition of styrene-ethyl acrylate copolymers as a function of their molecular weight fractions show a broader molecular weight distribution for ethyl acrylate-rich copolymers than for styrene-rich copolymers. 

Figure 12. Monomer feed profile using a linear power feed. Overall polymer composition 47.5/47.5/5—styrene/ethyl acrylate/methacrylic acid.

Styrene/ethyl acrylate random copolymers were prepared with ethyl acrylate..contents of 10,25,50,75 and 90% by weight. Examination of the 3C NMR spectra of the copolymers reveals that the carbonyl carbon of the acrylate ester is a sensitive probe of the sequence distribution in these copolymers. Figure 2 shows the carbonyl carbon resonance region for a sample containing 50%... 

Figure 2. The 13C NMR spectrum of a 50/50—styrene/ethyl acrylate copolymer prepared using a conventional uniform monomer feed process...

Figure 5. Linear power feed profile for a 50/50—styrene/ethyl acrylate copolymer in which ethyl acrylate decreases 1.0 -> 0 and styrene increases 0 -> 1.0 with...

A method for calculating apparent reactivity ratios based on run number theory has been applied to "starved-feed" styrene/ ethyl acrylate systems. The reactivity ratios found are in agreement with those determined from solution polymerization data. The further confirmation of the observed agreement between reactivity ratios determined at low conversions and those determined by run number theory in "starved-feed" high conversion copolymerization requires the analysis of other comonomer pairs. 

Figure 9. Correlation of calculated and measured triad fractions for a model 50/50—styrene/ethyl acrylate copolymer prepared with a linear power feed profile in which ethyl acrylate increases 0—> 1.0 and styrene decreases 1.0 — 0 with time (n = 0.16 r2 = 0.82 (A) EA-EA-EA EA-EA-STY = STY-EA-EA ...

Styrene, ethyl acrylate and fumaronitrile have been used to mask (3S)-pentacyclic nitrone 77. After a suitable elaboration of isoxazolidines 78 affording 79, the nitrone moiety was restored by thermally induced cycloreversion (145-180 °C), and the tricyclic intermediate 80 was obtained directly through intramolecular 1,3-DC (31-84% yield). This approach was applied to the synthesis of stereodifferentiated polyhydroxyindolizidines such as 81 <02EJO1941>. 

The freeze/thaw (F/T) stability of a polymer emulsion serves as a macroscopic probe for investigating the properties of the average particle in a polymer emulsion. A review of the factors which contribute to this stability is included. A study of styrene-ethyl acrylate-methacrylic acid polymers shows the existence of a minimum in the plot of minimum weight percent acid required for F/T stability vs. the minimum film formation temperature (MFT) of the polymer. This is considered to be a function of both the amount of associated surfactant and the minimum acid content. Thus, both the type of surfactant and the copolymer ratio—i.e., MFT—play major roles. Chain transfer between radicals and polyether surfactant resulting in covalently bonded surfactant-polymer combinations is important in interpreting the results. 

Styrene—Ethyl Acrylate (S—EA) Copolymers. At the inception of the research on F/T stability, it was evident that more than one polymer system would require investigation before adequate conclusions could be drawn regarding the various pertinent parameters. These include, in addition to the previous considerations, surfactant type and amount as a function of polymer type. 

To this end, work has been initiated on a series of somewhat less polar styrene-ethyl acrylate-methacrylic acid emulsion polymers. The first major difference encountered in changing from the MMA-EA-MAA to the S-EA-MAA polymers was the need for at least a 50% increase in surfactant to obtain a coagulate-free emulsion for the 100% styrene vs. 100% methyl methacrylate. The determination of the minimum weight percent of MAA required to yield a F/T stable emulsion for various copolymers gave the results listed in Table III. 

In another set of carboxylated emulsions prepared with similar Tg, styrene-ethyl acrylate (S-EA) copolymers showed no expansion, but MMA-EA copolymers did. This finding strongly suggested that monomer polarity is also an important factor. The more polar MM A copolymer apparently was able to interact with the highly polar aqueous phase and was thereby plasticized. 

Acyclic Reagents. The alkenylation protocol between styrene, ethyl acrylate, or acrylonitrile and a 5-bromo- and 5-iodopyrimidine leads to coupling products 275 (Scheme 98) [143] Methoxy-, methylthio-, and amino groups are tolerated. i A triflyloxy substituent may replace the iodo substituent. 1-Methyl- and l,3-dimethyluracil-5-yl triflate... 

Figure 3. HPLC-chromatogram of styrene-ethyl acrylate copolymers at different compositions and high conversion. Also shown is the styrene content obtained by HPLC calibration -) and on-line HPLC- H NMR experiments (o). (Reprinted from MacromolChem.Phys, Vol.201, LKramer, W.HiUer, H. On-line coupling of gradient-HPLC and NMR for the analysis of random poly[(styrene)-co-(ethyl acrylate)]s , 1662-1666, 2001, with permission from Wiley-VCH)...

Figure 3, i.e., 50/50-styrene/ethyl acrylate copolymer made by uniform (random), staged, or power feed processes (24). Using the carbonyl carbon of the acrylate ester as a probe of the sequence distributions in a series of random styrene/ethyl acrylate copolymer, assignments were made for the three major resonance regions in terms of triad sequences. Figure 6 illustrates the differences observed. In the... 

Figure 5. Effect of monomer feed profile on the dynamic mechanical properties of model 50/50-styrene/ethyl acrylate latexes. A. Uniform feed B. Two-stage process with stage I-EA, stage II-STY C.

Figure 7. Development of triad fractions as observed by carbon-13 NMR for a model 25/75-styrene/ethyl acrylate latex prepared by a linear power feed profile. (Johnston, Bassett, MacRury, Ref. 24)...

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