N Butyl methacrylate

Polystyrene-PDMS block copolymers4l2), and poly(n-butyl methacrylate-acrylic acid)-PDMS graft copolymers 308) have been used as pressure sensitive adhesives. Hot melt adhesives based on polycarbonate-PDMS segmented copolymers 413) showed very good adhesion to substrates with low surface energies without the need for surface preparation, such as etching. 

Two free radical-initiated polymerizations are used in turn as examples the homopolymerization of methyl methaK rylate and the copolymerization of styrene n-butyl methacrylate. 

With regards to the copolymerization, a recent kineuc study by Gruber and KneU (10 has indicated that styrene n-butyl methacrylate obeys the cla ical kinetic theory with regards to composition and sequence length to complete conversion. This theory is applied to high conversion to charau terize copolymer samples for GPC analysis. 

Polystyrene standards used were narrow molecular weight distribution sample produced by anionic polymerization and available from Pressure Chemical Co. Also sample NBS7C from the National Bureau of Standards was used. The sample of poly n-butyl methacrylate was obtained from Aldrich Chemical. It was produced by free radici polymerization with an Mw of 320,(XK) and an Mn of 73,500 (Cat. No. 18,153-6). 

Figure 8. Typical polystyrene n-butyl methacrylate chromatogram (low to intermediate conversions) showing monomer peaks at times 46.2 and 49.2 min resolved...

Figure 9 shows the result of injecting 10 gA of the total low molecular weight fraction from GPC 1 (Column Code A2) into GPC 2 (Column Code Bl). With this column code, GPC 2 is performing as a High Performance Liquid Chromatograph (HPLC). Separation is based upon solubility (i.e. composition differences) rather than upon molecular size. Methyl methacrylate monomer was used as a reference and added to the solution injected into GPC 1. Concentrations of n-butyl methacrylate, styrene and conversion are readily calculated from the peak areas and initial concentrations. 

Figure 10. Conversion vs. time, styrene n-butyl methacrylate (Wio = 0.767, 1.45...

Figure 11. Conversion vs. weight fraction styrene in monomer, styrene n-butyl methacrylate (samples as for Figure 10) ((------) ti = 0.68, r == 0.45 (------)...

Figure 21 shows the result of sampling a 50 50 blend of NBS706 and poly n-butyl methacrylate using Column Codes A4 and B4 (Table I) injecting a total of 1.5 mg into GPC 1. 

Figure 22. Separation of polystyrene n-butyl methacrylate (peak retention time ...

To study the bulk copolymerization of styrene n-butyl methacrylate both conventional and unconventional GPC analyses were used. The normally obtained chromatograms, (from dual U.V. detectors) primarily provided area ratios intficative of composition as a function of retention volume. However, even this information was only obtainable after average compositions had been otherwise determined. Furthermore, in general, since the GPC normally separates on the basis of hydrodynamic volume, the polydispersity of aU polymer molecular properties at e h retention time is of serious concern. 

Methyl and ethyl methacrylate polymers, although extensively used in Industry, do not possess the solubility characteristics (low polarity) that would make them appropriate for use over traditional oil paintings and other organic-based museum objects that might be sensitive to polar solvents such as alcohols, ketones and esters. Poly(n-butyl methacrylate), offered as an artists varnish in the late 1930 s, did not become widely accepted in the war-disrupted decade that followed. Accordingly, early in 1951, our laboratory began a detailed study of the higher alkyl methacrylate polymers for potential use as picture varnishes (1). 

Fig. 1 Chemical structure of water-soluble poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate-co-p-vinylphenylboronic acid (PMBV)...

C Spin-Lattice Relaxation-Times and n.O.e. Values of Resonance of Poly(n-butyl methacrylate) as 50% (w/w) Solution in Toluene-2H8... 

Fig. 57. Gladstone - Dale plots [Eq. (110)] for solutions of (a) polystyrene, (b) poly-n-butyl methacrylate, (c) polymethyl methacrylate165 = 436 nm)...

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