Dynamic mechanical analysis and

Other PDMS—sihca-based hybrids have been reported (16,17) and related to the ceramer hybrids (10—12,17). Using differential scanning calorimetry, dynamic mechanical analysis, and saxs, the microstmcture of these PDMS hybrids was determined to be microphase-separated, in that the polysiUcate domains (of ca 3 nm in diameter) behave as network cross-link junctions dispersed within the PDMS oligomer-rich phase. The distance between these... 

It was concluded that the filler partition and the contribution of the interphase thickness in mbber blends can be quantitatively estimated by dynamic mechanical analysis and good fitting results can be obtained by using modified spline fit functions. The volume fraction and thickness of the interphase decrease in accordance with the intensity of intermolecular interaction. 

Gel time values of the three systems measured as abrupt change in the slope of G (t) under isothermal curing conditions show that gelation occurs earlier in PWE system at all temperatures considered as shown in Table 11.27. ETPI behaves like a catalyst for the primary epoxy-amino reaction which dominates the cure until vitrihcation occurs. Dynamic mechanical analysis and dielectric spectroscopic analysis carried out by the authors also confirm the above conclusions. 

A series of poly(cycloalkyl methacrylates) has been investigated by dynamic mechanical analysis and solid-state 13 C NMR in order to characterise the... 

Dynamic mechanical analysis and the 13C NMR experiments performed on pure aryl-aliphatic epoxy networks, as well as on antiplasticised systems, have led to a deeper insight into the molecular motions involved in the glassy state of these epoxy resins. 

The estimation was made by putting different data together, which included thermal transition data obtained by dynamic mechanical analysis and spectroscopic data quantified mainly by solid-state NMR techniques [43-48], The binary compositions situated in an enclosed area, denoted by connection of dotted lines in the scale list, can be assumed to be a highly compatible state of mixing. a Obtained by hydrolysis treatment of MC/P4VPy... 

In conclusion, it has been shown that the predicted order of miscibility in composite latex particle systems is not necessarily bourne out when the extent of miscibility is guaged by dynamic mechanical analysis, and, very recently, by the same authors using solid-state NMR spectroscopy. Control over particle morphology, and, hence, over damping behaviour can be exercised by the differences in hydrophilicity between the polymer pair in question, by the degree of crosslinking in the first network and by whether or not the first-formed polymer is above or below its Tg when the second monomer is polymerised. 

To extend the basic property profile of the bulk polymer and help better understand the high temperature mesomorphic state, high molecular weight PDPhS and its low molecular weight oligomers have been examined by X-ray diffraction analysis, DSC, dynamic mechanical analysis and high temperature optical microscopy. The results of this examination and interpretation of the results are presented. 

The book opens with the first three chapters devoted to differential scanning calorimetry (DSC), the most commonly used thermal method. These chapters cover the principles, optimal use, and pharmaceutical applications of the method. Subsequent chapters explore modulated temperature DSC, thermogravimetric analysis, thermal microscopy, microcalorimetry, high sensitivity DSC, dynamic mechanical analysis, and thermally stimulated current, all of which have attracted great interest within the pharmaceutical field. Each chapter includes theoretical background, measurement optimization, and pharmaceutical applications. 

Miscibility of PI blends of different structures was reported by Hasegawa et al. [1991] using charge-transfer fluorescence spectra, dynamic mechanical analysis, and phase-contrast microscopy. These blends were BPDA/PDA PI with PMDA/PDA and PMDA/ODA PFs (BPDA = biphenyltetracarboxylic dianhydride PDA = p-phenylene diamine ODA = oxydianUine PMDA = pyromellitic dianhydride). Two patents issued virtually simultaneously noting the utility of miscible PI blends for gas separating membranes [Burgoyne et al., 1991 Kohn et al., 1991]. 

Several experimental approaches have been applied for determining the fiber Tg under hot wet conditions [199-203]. Aiken et al. [199] compared the Tg of a commercial acrylic yarn in the dry state and in water using dynamic-mechanical analysis, and observed a reduction from 92 to 72°C. Bell and Murayama [200] observed that the Tg of a commercial AN-NA copolymer decreased from 128°C when dry to 80°C in a 100% relative humidity atmosphere. Gur-Arieh and Ingamells [201] related the extension in length of Acrilan filaments to a Tg reduction and showed a shift from a 90°C in air to 57°C in water. Finally, Hori et al. [202] used DSC to show that the Tg of four kinds of acryhc fibers decreased with increasing water content and approached an almost constant value for all four fibers. 

This study compared methacrylate and acrylate polymers to structural analogs with fluorinated ester groups. Two types of relaxations were characterized, the primary relaxation associated with the glass transition and secondary relaxations associated with side group motion and localized segmental motion. Dielectric analysis was used to characterize the response of dipoles to an electric field as a fimction of temperature. Mechanical properties were analyzed via dynamic mechanical analysis and stress relaxation measurements. Relaxation behavior was interpreted in terms of intermolecular and intramolecular mechanisms. 

Dynamic Mechanical Analysis and Stress Relaxation Behavior. Samples were compression molded into bars of the dimensions 38.xl2.5x0.78 0.007 mm and 65.x9.7xl.7 0.007 mm in a Carver laboratory hot press model C. A TA Instruments 983 DMA, which was operated in the fixed frequency mode, was used to characterize the storage and loss moduli as a function of temperature. Samples were scanned at fi-equencies from 0.05 to 10.0 Hz over a temperature range from -150 C to above the glass transition temperature. The displacement was 0.4 - 0.6 mm. Stress relaxation curves were determined for the same size samples at a constant strain. The sample was displaced for 10.0 minutes and then allowed to recover for 10.0 minutes. The stress data were taken in five degree increments. A microprocessor controlled Liquid Nitrogen Cooling Accessory (LNCA) was used for sub-ambient operations. 

A much broader variety of topics are covered than in previous volumes, due to the growth in the field of Thermal Analysis. Specific topics covering such techniques as differential scanning calorimetry, combined thermogravimetric procedures, dynamic mechanical analysis and a variety of novel kinetic analyses are covered. 

Gelation of plasticized polymers can be conveniently observed by a dynamic mechanical analysis and microscopy (see more on this subject in Chapter 9). Aggregation and formation of clnsters in solntion can be followed by a dynamic light scattering experi-... 

Costa, M. L.,Ahnida, S. R, and Rezende, M. C. Hygrothermal effects on dynamic mechanical analysis and fracture behavior of polymeric composites. Materials Research, 8(3), 335-340 (2005). 

Wang and co-workers [4] have discussed the thermal stability of PDMS-urethane copolymers using a combination of differential scanning calorimetry, dynamic mechanical analysis and cone calorimetry. 

Thermal analysis is well suited for characterizing and identifying plastics, as their properties are temperature dependent. It involves methods in which the substance is subjected to a controlled temperature program and the changes in the physical and chemical properties are measured as a function of temperature or time. The ambient atmosphere also influences the properties of plastic. Thermal analysis comprises traditional techniques differential scanning calorimetry (DSC), differential thermal analysis, thermogravimetric analysis, thermomechanical analysis, and more recent methods pressure differential scanning calorimetry, dynamic mechanical analysis, and differential photocalorimetry. 

Information on dynamic mechanical analysis and properties is found in Chap. 3, Properties, and Chap. 4, Processes. ... 

Rheology, Dynamic Mechanical Analysis, and Dielectric Analysis. 

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