Matrix molecular weight

To date, the melt state linear dynamic oscillatory shear properties of various kinds of nanocomposites have been examined for a wide range of polymer matrices including Nylon 6 with various matrix molecular weights [34], polystyrene (PS) [35], PS-polyisoprene (PI) block copolymers [36,37], poly(e-caprolactone) (PCL) [38], PLA [39,40], PBS [30,41], and so on [42],... 

J. F. Tassin and L. Monnerie, A fluorescence polarization study of matrix molecular weight on the relaxation of a labeled molecule in a stretched polymer melt, J. Polym. Sci. Polym. Phys. Ed., 21,1981 (1983). 

Figure 11.4. Typical stress-strain curve of a PVA/nanotube composite. The material is a fiber containing 25wt% of MWNTs in a PVA matrix (molecular weight 195 000,99% hydrolized).

The formation of polymer-polymer complexes as a rule is observed in aqueous media5,33. The viscosity of complexes in water is about 0.05-0.10 dl/g and close to that of globular proteins. Aqueous solutions have some features low intrinsic viscosity values are independent of the matrix molecular weight, the absence both of the concentration dependence of the reduced viscosity and the polyelectrolyte anomaly, and high values (about 30 s) of the sedimentation constant. 

The PAA-PVP system in methanol and the PMAA-PVP system in DMF display the typical properties of polycomplexes, namely low values of intrinsic viscosity independent of the matrix molecular weight (for PVP with molecular weight of 50 MO and 560000, the intrinsic viscosity [ /], of PA A-PVP complexes in methanol is equal to 0.07 dl/g), the absence both of the concentration dependence of the reduced viscosity, and of the polyelectrolyte anomaly. 

T Vispersions of acrylic polymer beads in rapidly polymerizable liquids are important biomaterials (I, 2). The biocompatibility and functionality of dental restoratives, dental prostheses, and surgical prostheses depend on the mechanical properties of these biopolymers as well as on their physical and chemical constitution. This investigation was part of a continuing program to determine the influence of microstructural parameters on the mechanical properties of these multiphase systems. The effects of the volume fractions of dispersed phase and matrix, molecular weight of the matrix, chain length and concentration of crosslinkers, impact modifiers, and filler were studied in terms of microstructure, hard-... 

Now we compare the variation of the brush thickness L with P, as predicted by Eq. (59), with the available data. The first experimental study of this problem [265], performed by SIMS for a series of very short (as compared to a standard depth resolution of this technique) (COOH)dPS (N=125-413) end-anchored chains annealed at different temperatures and with different matrices used (T= 108 °C for P=63, and 160 °C for P=4460), revealed identical unswollen brush conformation for both used matrix molecular weights. The variation of the brush height L with P, at a constant coverage other groups in experiments performed later [241,243]. On the basis of the cumulative data for the Pl-dPS (N=893) brush in the PS host matrix (P=88,495, and 3173), presented in Fig. 37, we were able to achieve an equi-o situation (o=3.7.10 3, see arrow in Fig. 37 and corresponding symbols (A, ) in Fig. 38 as described in... 

The ductile-to-brittle transition in PA has been studied as a function of (1) materials parameters, including matrix molecular weight (4), type of polyamide (5, 6), and type of rubber (7), and interface (3), and (2) morphological parameters, including rubber concentration (9), particle size (9), ligament thickness (9, 10), use of very small particles (5, 11), and particle distribution (2). When one of these variables is studied, other variables are often changed too. Only in experiments with large series can some idea of the effect of a variable be obtained. 

Mariani, P.D.S.C., Allganer, K., Oliveira, F.B., Cardoso, E.J.B.N., Irmocentini-Mei, L.H. Effect of soy protein isolate on the thermal, mechanical and morphological properties of poly (epsilon-caprolactone) and com starch blends. Polym. Testing 28(8), 824—829 (2009) Fornes, T.D., Yoon, P.J., Keskkula, H., Paul, D.R. Nylon 6 nanocomposites the effect of matrix molecular weight Polymer 42(25), 09929-09940 (2001)... 

Kes Oshinski, A. J., Keskkula, H., Paul, D. R. The role of matrix molecular weight in rubber toughened nylon 6 blends 2. Room temperature Izod impact toughness. Polymer Vol. 37 (1996) 22, 4909 918. 

DIFFUSION OF POLYSTYRENE IN POLYSTYRENE. EFFECT OF MATRIX MOLECULAR WEIGHT. 

Clarke, C.J., Jones, R.A.L., Clough, A.S. The effect of matrix molecular weight on the kinetics of formation of end-adsorbed polystyrene layers from the melt. Polymer 37, 3813-3817 (1996)... 

Here Do is the limiting diffusion coefficient, a is a scaling prefactor, and i/ is a scaling exponent. If the probe and matrix molecular weights P and M differ, an elaborated form... 

Brown and Rymden [100] used QELSS to study diflfusion of linear polystyrenes and silica spheres through polymethylmethacrylate-.toluene. Toluene and PMMA are almost exactly index-matched, so scattering arises from the dilute probe chains. The matrix molecular weight M spanned 110 kDa- 1.43 MDa. Probe polystyrenes had P of 2.95, 8, and 15 MDa, with M /M of 1.06, 1.08, and 1.30, respectively. Figure 21 shows Dp/Dpo... 

Lodge and collaborators have reported an extensive series of studies of probe diffusion in polymer solutions, using QELSS to measure Dp of dilute probe polystyrenes in polyvinylmethylether orthofluorotoluene. Variables studied include the probe and matrix molecular weights, the matrix concentration, and the topology (linear and star) of... 

Molecular weight dependence of the self and probe diffusion coefficients ) and Dp for molecular weight P probes in solutions of matrix polymers at a fixed concentration c. The fits are to stretched exponentials Z oexp(—aM ) in matrix molecular weight M. The Table gives the best-fit parameters, the percent root-mean-squaxe fractional fit error %RMS, the system, and the reference. Square brackets [ ] denote paxameters that were fixed rather than floated. Abbreviations as per previous Tables, and DBP-dibutylphthalate. 

For two samples with the same Dp/Do but very different matrix molecular weights (44, 8420 kDa), Nemoto, et al. [115] also measured the shear viscosity, finding that r] differed by more than two orders of magnitude between the two samples. Nemoto, et al. thus showed that Dp is not governed by the shear viscosity of the matrix solution. (The original paper did not specify which solution was the more viscous. Note that the comparison is being made at fixed Dp/Do, not at fixed c, where the correspondence would be self-evident.)... 

The above sections summarize a detjuled examination [1] of nearly the entirety of the published literature on polymer self-diffusion and probe diffusion in polymer solutions. Dependences of D, and Dp on polymer concentration, probe molecular weight, and matrix molecular weight were determined. We now attempt to extract systematic behaviors from the above particular results, asking What features are common to self- and probe-diffusion of all polymers in solution ... 

Fig. 11.24 Brittle-to-ductile transition temperature as a function of matrix molecular weight, 30 wt.% PP-CaC03 composites (From Zuiderduin et al. (2003) reproduced with permission of Elsevier)...

Effects of MMT and Matrix Molecular Weight on Dispersed Phase Particle Size... 

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