Normalized DSC thermogram

Figure 4.12 Normalized DSC thermograms of PET films annealed at 180 °C for the indicated times [47]. From Lin, S. and Koenig, J., J. Polym. Sci., Polym. Symp. Ed., 71, 121-135 (1984), Copyright John Wiley Sons, Inc., 1984. Reprinted by permission of John Wiley Sons, Inc...

Fig. 7 DSC thermogram of coalesced PET. First (upper), second (middle) heating and (lower) interim cooling scans. (Note that the heat flow units on the ordinate are only appropriate for the cooling scan and that the magnitudes of the melting endotherms and crystallization exotherm obtained from them are actually nearly identical.) PETs normally processed from their solutions and melts, on the other hand, do not evidence recrystallization upon rapid cooling (—200° C min-1) from their melts [33]...

DSC thermograms obtained during thawing of starch pastes (sucrose not included) (a) without hydrocolloid, (b) with xanthan gum, (c) with guar gum, and (d) with sodium alginate. Upper curves not-annealed samples numbers indicate Tg onset. Lower curves samples annealed at - 4.5°C numbers indicate onset. Curves were not normalized and correspond to different mass samples. 

For both cases, when the Ay-value (see Sect. 3.2.S.2) between these newly formed crystals and the melt of the minor phase is smaller than that of all other heterogeneities present in the minor phase (except probably the nuclei of type 1 normally nucleating arormd the bulk Tc i r), its associated specific undercooling must be so small that the crystals can induce the crystallization of that minor phase from the instant of their own creation (Frensch et al. 1989). Consequently, a single coincident crystaHizatiOTi peak will be registered in DSC thermograms. 

Figure 2. Normalized relative H NMR intensity of methylene groups of Sil-to-ODA increase distinctly around 38 °C, which is just around the peak-top temperature of its DSC thermogram.

For thermally initiated reactions, is a function of time. Its course can be determined experimentally by measuring the thermal conversion as a function of time, while the reaction proceeds under normal operating conditions. These experiments can be carried out with DSC or, preferably with a Reaction Calorimeter. The Tcf curves can be obtained in the evaluation of the thermogram by using Equation 5.24. Its maximum (MTSR) can be searched from the TCf curve. 

The expansion capacity up to low foam densities can be influenced by the concentration of the pentane in the beads. Normally, 6-7 wt % pentane is used in standard EPS types and less than 3.5 % in so-called low-pentane types [28]. The thermogram from the differential scanning calorimetry (DSC) of EPS beads shows only one glass transition temperatures ( Tg), indicating the state of chemical solution of polystyrene in pentane. Tg falls by around 7 °C per wt % pentane [29]. 

The influence of HPAM composition on Tg was determined for the acid form of the polymer. For some HPAM and AM-co-AA copolymers, it was found that the intensity of the Tg region of the thermogram was very strongly influenced by heatiHig rate, sample size or DSC sample type/mode. These effects may be related to the physical form of the sample (i.e., dense polymer vs. freeze dried polymer vs. thin films). In order to normalize the data for such effects, each of the T values shown for HPAM (Table 2) and AM-co-AA copolymers (Table f) is an average of at least six determinations as indicated. 

Figure 10.32 DSC heating thermograms of PBHA/PAA blends at various compositions crystallized from the isotropic meit (second run, heating rate 10 K/min).The traces are normalized to 1 mg samples. Reprinted from Praceiia and Bresci [131], Copyright 1995, with permission from Taylor Francis.

Under TG and DSC, TPF resin showed good thermal stability together with curing characteristics similar to those of the original PF adhesive. Similar DSC experiments were performed on a commercial phenol-formaldehyde adhesive plus Southern pine Pirns sp.) sap wood treated with a chromated copper arsenate (CCA) preservative [63], The thermograms indicated that curing can be accelerated at lower temperatures than normal depending upon the state of CCA in the wood. 

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