PEO/PMMA

The alcoholate was alternatively reacted with tin octoate to initiate the polymerization of L-lactide (LL) and produce (PS)(PEO)(PLL) star terpolymer. In another application of the method, the 1,1-diphenyl -alkylpotassium intermediate (I) was used to initiate the polymerization of MM A at —78 °C. After de-protecting and activating the hydroxyl group, the polymerization of ethylene oxide was initiated, leading to the formation of the (PS)(PMMA)(PEO) star terpolymer. If e-CL is polymerized instead of EO, then (PS)(PMMA)(Pe-CL) stars are produced. Limited characterization data were given for these stars. In all cases two of the arms grow from the star center and thus cannot be isolated and characterized. However, interesting amphiphilic structures were obtained. 

Chang et al. reported the miscibility of poly(vinylphenol) (PVPh) with poly(methyl methacrylate) (I MMA) Figure 1 shows the C CP/MAS spectra of pure PVPh, PMMA, PVPh-co-PMMA, PEG, and PVPh-co-PMMA/ poly(ethylene oxide) (PEO) blends of various compositions with peak assignments. VPh contents of PVPh-co-PMMA is 51 mol% and Mn of PEO is 20,000. The spin lattice relaxation time in the rotating frame (Tip ) was measured to examine the homogeneity of PVPh-co-PMMA/PEO blends on the molecular scale. 

Table 1. Tip (ms) values of pure PVPh and various PVPh-co-PMMA/PEO blend compositions...

Table 1 also shows that both pure PVP and PVPh-co-PMMA/PEO blends exhibit only single-exponential relaxation through out all of the blends at... 

A typical value of D is 10 m" s . For Ti of 5 ms, the dimensions of these PVPh-co-PMMA/PEO blends are below 2-3 nm in the amorphous phase. Interestingly, the has a minimum value for the PVPh-cu-PMMA = 40/60 blend showing that the overall chain mobility is maximal at this composition. This observation agrees with the earlier result concerning hydroxyl group association obtained by FTIR and solid-state NMR. In addition, all of the blends show a shorter Ti,/ than that of the pure PVPh-co-PMMA implying that the PVPh-co-PMMA mobility also increases with the increase of PEO content. 

Table 17.3 Effect of total molecular weight of the PMMA-PEO diblock. ...

The chemical nature of the monomer also plays an important role. For example, stable latexes could be produced using a PMSt(PEO) graft but not with a PMMA(PEO) graft. 

Miklesova, K., Szocs, R, Free-radical decay in a polymer blend PMMA/PEO studied by the EPR method. European Polymer Journal 1992, 28, 553-554. 

With this technique the possibility of the production of different morphologies was suggested, that is, smooth and porous fibers as well as beaded fibers. Moreover, pol5miers such as PLA, PMMA, PEO, PS, and PVC have been used to produce micro- and nanosized fibers with diameters as low as 40 nm. 

Figure 10.31. Ionic conductivity of PMMA/PEO system containing LiC104 versus molecular weight of poly(ethylene oxide) in the range of molecular weight from 200 to 6000. [Adapted, by permission, from Qi Wang Jun Gao Yuqin Qian, Mr. Polym. J., 32, No.3, March 1996, p.299-302.]...

Fig. 10.10 ATR-IR images of PMMA/PEO system. The top row shows images based on the spectral band of PMMA, the middle row shows images based on the spectral bands of PEO, and the bottom row shows images based on CO2 dissolved in the...

PMMA(iPMMA aPMMA PMMA) / PEO (oligomers = 400-20,000 g mol ) Thermal properties Hamon et al., 2001... 

The earliest example of block copolymers made using CuAAC was from Opsteen and van Hest in 2005, when they coupled alkyne-terminated polymer with azide-terminated polymer in excellent yields to make several diblocks (see Scheme 4). While this example was an excellent proof of concept, the polymers formed (PS-PMMA, PS-poly(ethylene oxide (PEO), PMMA-PEO) can easily be synthesized by sequential CFR polymerizations, or by the use of PEO-based macroinitiators. It has, though, served as a template for researchers to use CuAAC to make block copolymers that might be prohibitively difficult or impossible to synthesize with only previously existing polymerization techniques. For... 

Radhakrishnan and Venkatachalapathy (Radhakrishnan et al. 1996) used the X-ray diffraction to study the crystallization, the PMMA/PEO blends cast from three solvents. The solvent effect is demonstrated from the large differences in the crystallinity values. 

Fig. 12.22 Temperature dependence of the relaxation times of the segmental dynamics (a-relaxation) for the blend system PMMA/PEO at the indicated concentrations solid squares, PMMA solid circles, PEO. The solid lines correspond to fits of the VFT equation to the data of the pure polymers. The dashed lines are due to fits of the LM model with the Kuhn lengths for PMMA as adjustable parameter (1 = 1.62 nm, theoretical value 1.38 run) (Data were taken from reference Mpoukouvalas and Floudas (2008). The concentration dependence of the whole blend was described by the Fox/Flory equations. For details see also reference Mpoukouvalas and Floudas (2008))...

Similar results have been also reported by Adachi et al. (Urakawa et al. 2002) for PVME/PS, for the blend PMMA/PEO (Maranas 2007), or for blends of PVDF/ PMMA (Sy and Mijovic 2000). Besides dielectric spectroscopy quasielastic neutron scattering is found to be quite useful to investigate the molecular dynamics of dynamic asymmetric polymer blends because spatial information is provided by this technique (see, for instance, Tyagi et al. 2006, 2007). For a more detailed discussion, the reader is referred to the literature (Colmenero and Arbe 2007). 

Fig. 13.10 Relaxed enthalpy versus relaxed volume for blends PMMA (O) and PMMA/PEO blends with (a)...

One of the blends whose aging properties have been extensively studied is PMMA/ PEO (Shimada and Isogai 1996 Vemeletal. 1999 Slobodian etal.2(X)6a,b Rihaetal. 2007). The blend consists of a fuUy amorphous polymer (PMMA) and a ciystallizable component (PEO). Miscibility in the melt state occurs when the PMMA content is above 70-80 %, but phase separation in the glassy state has been reported as indicated by the appearance of heterogeneous structures with domain sizes of 20-70 nm. 

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