DMA curve

Tests of a graphite-reinforced polyimide composite (C6000/PMR15) did not show any effect of radiation exposure (1 MEV electrons 6x109 rad total dose) on the thermal expansion behavior (14). DMA curves for unirradiated and irradiated composites were essentially identical over the temperature range of the thermal expansion measurements. 

Thermal mechanical analysis (Dupont 990/942 IMA), and dynamic mechanical analysis (Dupont 1090/982 DMA) curves for a designed set of model formulations were evaluated for CTE and tensile storage modulus as a function of filler level and elastomer additive type and level. Fifteen formulations were prepared with 68-75% filler, 0-4% silicone elastomer A, 0-4% non-silicone elastomer B and the balance 17-32%. Both elastomers have Tg s below room temperature. An extreme vertices formulation design was generated by computer (Table I). 

Figure 11.15. DMA curves of styrene-buladiene rubber (SBR/PB in Table 11.6X37).

Figure 2.7 DMA curves of iPP/PBl blends. (From Reference 116 with permission from John Wiley...

Figure 22. DMA curves for a model cured bis-GMA/TEGDMA specimen for resin composites [59]. Reproduced with permission from Elsevier Science.

Figure 12 DMA curve of poly(caprolactone) obtained in single cantilever bending at 1 Hz. Heating rate 2°C min in air...

The following items should be included along with the recorded TMA or DMA curves when presenting the results ... 

Figure 4.136 Storage modulus vs. temperature (DMA curves) for Celanese Thermx PCT resins [12].

Shown in Eig. 3.1 and 3.2 are two example DMA curves obtained by us for two materials based on the single diisocyanates MDI or DBDI, with analogous structures consisting of the diol chain extender BDO and the polyether PTHF. 

Example selected DMA curves of selected materials listed in Table 1.1 are shown in Fig. 3.19-3.22. 

Figure 5.12 DMA curves for neat PET and PET/MMT hybrids. Reproduced from Ref [14] with permission.

Figure 7.58 DMA curves for polyepichlorohydrin (PECH)-poly(methyl methacrylate) (FMMA) interpenetrating f)olymer networks (IPNs) with different compositions [44. PECHrPMMA mass ratio I, 100 0 II, 75 25 III, 65 35 IV, 50 50 V, 35 65 VI, 0 100...

Characteristic parameters of PP nanocomposites calculated from DMA curves ... 

Starting from early publications [72] and in subsequent works, three relaxation regions have been observed in PE and similar flexible-chain polymers at low frequencies / (10 -1) Hz relaxation I at 150-200 K, relaxation II at 240-270 K, and relaxation III over the broad temperature range, for instance, of 300-370 K for PE or 300 20 K for POM. In addition, rather strong suppression of relaxation II may be observed in high-crystalline polymers (see, e.g., DMA curve presented for POMlnFig.il). 

Figure 23. DMA curves of 75% PE containing LDPE-PVC SWiplQS.(Reproducedfrom reference 26 with permission of J. Wiley and Sons Ltd.)...

Fig. 5.9 Comparative DMA curves of the virgin Copolymer XVII solid line) and the cross-linked polymer Copolymer XVIIcL dashed line). Reproduced from [24] with permission of the American Chemical Society...

Figure 5.22. DMA curves for polycarbonate at several frequencies. [From Chartoff...

Crystal crystal transitions sometimes can appear on the DMA curves. Figure 5.37 shows the storage modulus-temperature data for an as-spun monofilament and a drawn monofilament prepared frompoly(2-methylpenta-... 

Obviously, the autotension mode will influence the DMA curve, since it may lead to different levels of shrinkage, creep, and change in orientation. Almost all presently available commercial DMA instruments have special fiber and film fixtures sometimes the same fixture can be used for both types of measurements. 

The dynamic properties of polyurethane composites made with treated rubber particles can also be very similar to those of the unfilled polyurethane. Comparison of d5mamic mechanical analysis (DMA) curves for composites composed of surface-modified rubber particles in polyurethane and corresponding curves for the unfilled polyurethane show nearly identical hysteretic heating. End products, such as wheels and rollers, made in either unfilled pol5mrethane or in composites comprising treated rubber particles/pol)mrethane have essentially identical heat build-up in dynamic applications. 

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