Poly PMMA curve

PMMA, on the unmodified porous glass and silica gel, and the universal calibration curves for polystyrenes and poly(methyl methacrylates) did not coincide (10,12,19). 

Table IV compares the X-ray exposure characteristics (at 8.3 X, Al Kai,2 emission line) of the halogenated resists and of PMMA Elvacite 20U1. It can be seen that poly(2-ehloroethyl methacrylates) and poly(2-bromoethyl methacrylates) exhibit a low sensitivity unlike poly(2-fluoroethyl methacrylates) and poly(2-, 2-,2-trifluoroethyl methacrylates) which are more sensitive than PMMA as shown in Figures 2a, 2b, 2c, 2d where the dose-thickness curves of these resists are plotted. The low sensitivity of the PC1EMA and PBrEMA samples may be explained by some competing crosslinking reactions which could occur during exposure as a result of C-Cl and C-Br homolytic bond scissions as noted by Tada...

Upadhyay et al. [98] used primarily correlated XPS and water contact angle measurements to study the surface degradation and recovery of amorphous films of a PMMA and a poly (aryl ether ether ketone) (PEEK). Surface modification of the films was carried out in a dielectric barrier discharge (DBD) unit, samples being treated with different dose levels of dielectric discharge. The modified (treated) samples were then stored for one month and re-examined. Figure 35 shows C(ls) and 0(1 s) XPS envelopes and their curve-fitting deconvolutions,... 

Thus, we have chosen the alternating copolymer of DMBZMA with MST as our resist material for its high thermal stability (Tg=210°C). TGA curves of the DMBZMA-MST copolymers are compared with that of PDMBZMA in Figure 5. Although incorporation of MST does not affect the deprotection temperature, the copolymers exhibit lower main chain stability than PMAN (PDMBZMA becomes PMAN above 260°C) and behave like PMMA and poly(a-methylstyrene) in terms of their main chain stability. 

Interpretation of these curves show that Poly (vinyl chloride) (PVC) first loses HC1 later the mixture of unsaturated carbon-carbon backbone and unchanged poly (vinyl chloride) partly degrades to small fragments. Poly (methyl methacrylate) (PMMA), branched polyethylene (HPPE), and polytetrafluorethylene (PTFE) degrade completely to volatile fragments, while a polyimide (PI) partially decomposes, forming a char above 800°C. 

Needless to say, the rheological properties of polymer mixtures are complex and nearly impossible to predict. Figure 4.12 shows the viscosity of a natural rubber (NR)/poly(methyl methacrylate) (PMMA) blend (top curve) as a function of percentage NR [2]. For comparison, the predictions of four common equations are shown. The equations are as follows ... 

Figure 8. GPC curves of PMMA derived from poly(TrMA) (A = No. 21, and C = No. 19 in Table IV) obtained with Sp-BuLi in THF and toluene at —78°C.

Figure 7 illustrates the GPC curves of poly(TrMA) obtained by LiAn in toluene (A) and THF (B) Figure 8 is the GPC curves of the PMMA derived from the poly(TrMA) obtained with Sp-BuLi. Both polymers obtained in THF with LiAn and Sp-BuLi showed rather narrow distributions and initiator efficiency was about 100%. The polymerization in toluene was complicated and a large portion of the initiators was consumed for the formation of oligomers. 

Figure 2. Illustrative method for generating PMMA molecular weight and HDV calibration curves in TFE using a poly sty rene-HDV calibration curve in...

For compounds bearing acrylate or methacrylate groups, the copolymer compositions were almost the same as the monomer feed compositions, and the molecular weights were nearly identical to that of poly(methyl methacrylate) (PMMA) synthesized as a control under the same reaction conditions. In addition, the dye-bearing repeat units were present uniformly in all molecular weights, as seen by comparing GPC molecular weight distribution curves determined by differential refractometry and by visible absorbance detection at the X of the... 

Experimental cloud-point curves are fitted by Eq. (8.1), selecting an adequate function for /. Depending on their structures, thermoplastics are more or less soluble in epoxy monomers poly(methyl methacrylate), PMMA and poly(styrene-co-acrylonitrile), SAN are quite soluble in liquid DGEBA, but the other thermoplastics shown in Table 8.1 are only partially miscible (Pascault and Williams, 2000). 

Fig. 1.17 Comparison of theory and experiment for preferential adsorption coefficient, X, of poly(alkyl methacrylate)s in 1,4-dioxane-methanol. (pso = methanol volume fraction). Points Experimental results from ref. [6], (o) PMMA (alkyl = Me) (A) PEMA (Et) ( ) PiBM (iBu). Association equilibria theory. (2-A) Calculated with the parameter values shown in Table I and numbered as 4-6, Curves (a) PMMA (b) PEMA, (c) PiBMA. (2-B) Calculated with the parameter values shown in Table I and numbered as 10-12. Curves (a) PMMA (b) PEMMA (c) PiBMa. (From ref. [120])...

For demonstration, the SEC behavior of different polymethacrylates is given in Fig. 6. On silica gel as the stationary phase and methyl ethyl ketone as the eluent, all polymethacrylates elute in the SEC mode. The calibration curves of elution volume vs. molar mass for poly(methyl methacrylate) (PMMA), poly(ferf-butyl methacrylate) (PtBMA), poly( -butyl methacrylate) (PnBMA) and po-ly(decyl methacrylate) (PDMA) reflect the inability of the system to separate dif-... 

Besides the overall composition of blends and random copolymers, valuable information can be obtained in the case of block copolymers. If a block copolymer contains a homopolymer fraction, a shoulder or second maximum in the MMD curve can be obtained that should have a different chemical composition. Figure 9 shows the MMD of a block copolymer of methyl methacrylate and decyl methacrylate, in which a second lower molar mass maximum can be identified as poly(decyl methacrylate) (PDMA) by dual detection [37]. The increase in the PDMA content with molar mass in the main fraction is reasonable and corresponds well with what is expected from the synthesis. It is worth noticing that this type of information can only be obtained by the D-RI detector combination, because both PDMA and PMMA have a similar low response in UV. 

Fig. 2a. Precrosslinked poly(organosiloxane) particles (5 mol% T units) before grafting of PMMA (degree of grafting 50 %) transmission electron micrographs, volume distributions, cumulative curves...

Films of PMMA with 20 to 30% poly(epi-chlorohydrin) require only 1/2 to 1/4 the exposure to produce patterns compared to PNNA alone. Thinning-exposure curves also suggest a sensitivity increase of 3 or 4 times. Contrast suffers somewhat, but patterns are producible when a nitride-supported gold mask is used. 

Figure 14.25 Stress-strain curves for poly(methyl methacrylate) (PMMA) in...

Figures 3.7 and 3.8 shows the frequency dependencies of Ti and NOE measured for the CH2 (rrr) carbon of poly(methyl methacrylate) (PMMA) in a deuterated chloroform solution at 55°C [10]. Different curves indicate the simulated results obtained by using the box-type distribution, log- distribution, 2r and 3t models described above. As is clearly seen in Fig.

Figure 6.3. The metastable phase diagram for the polyure-thane-poly(methyl methacrylate) SIN at 60°C. The PMMA gels at and above the plane Gj- U -PU. The intersection of the PMMA gelation plane and the surface along the curve A represents the condition of simultaneous phase separation and PMMA gelation.

In many studies of wettability Zisman and coworkers have used the contact angles of a series of n-alkanes as a convenient means for determining for low energy solid surfaces [5,6,13,20]. In Figure 2 are plotted the cos 9 vs. 7lv° curves for the n-aUtanes on PMMA surfaces containing 0.5% additive I and 1.0% additive II. The critical surface tensions with additives I and n were 19 and 20 dynes per cm., respectively, representing a decrease of about 20 dynes per cm. from the value of obtained with the additive-free surface. Since the y values of 19 and 20 dynes per cm. are very close to that of 18 dynes per cm. reported by Fox and Zisman [l3] for the n-alkanes on poly-tetrafluoroethylene surfaces, it is apparent that a number of perfluoro-alkane groups are present in the outermost part of the surface phase with the principal axis of each carbon-carbon chain parallel to the surface. 

Themodynamically induced shear degradation also has been investigated using solutions of anionically polymerized poly(n-alkyl methacrylate)s in poor solvents Three different lengths of the alkyl substituents (methyl PMMA n-butyl PBMA -decyl PDMA) were used in the course of the study. As an example for the thermodynamic characterization of these systems, Fig. 6 shows the cloud point curves of PDMA dissolved in -butanol... 

Figure 2.6 shows the calibration curves for poly(n-butyl methacrylate) (PnBMA), poly(decyl methacrylate) (PDMA), poly(methyl methacrylate) (PMMA), poly(ferfbutyl methacrylate) (PtBMA). It can be seen that the lines are almost parallel to each other, which implies that the slope hi is approximately constant, whereas bo varies. The changes in bo correspond to a change in the molar mass, and they may be quite large. For instance, when tetrahy-drofuran (TUF) is used as a solvent, polystyrene (at a given elution volume) has a mass tirat is about two times the mass of polycarbonate. It can be concluded that every polymer has its own calibration line, corresponding to a specific set of values for bo and b in Eq. 2.25. 

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