Thermal Dimensional Stability

An important part of this study was to recognize and address difficulties resulting from processing on polymeric substrates. Problems encountered included substrate handling, stability of the substrate, surface smoothness of the substrates, and effects of chemical exposure. Effective encapsulation of an OLED on a flexible polymeric substrate is a challenge but not one we will address in detail here. 

Thermal and dimensional stability are critical in enabling a film to withstand the process temperatures, to ensure precision registration of the different layers in the 

Although pre-annealing the substrate can greatly reduce shrinkage, and careful process design can reduce the swelling effects of solvents and water, additional measures are still required for the dimensional stability. 

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Factors that influence thermal dimensional stability also affect fatigue strength. This is a result of the substantial heating that is often encountered with fatigue, particularly in TPs. 

PEN films provide specifications that meet the requirements. PEN shows high mechanical properties, low fogging during manufacture and storage, and excellent thermal dimensional stability, and can be made photo-reactive with the gelatin being reactive. Consequently, it is a good support material for advanced photosystems [55, 56],... 

Fig. 8 Thermal dimensional stability of lignin/synthetic plastic in the thermo stabilization process.

Thermal dimensional stability, being better for the solid polymer than for the gas. 

Immiscible, but transparent, are blends of PPE with a copolymer of cyclohexanedimethanol, ethylene glycol, and terephthalic acid (PCTG) — the clarity was achieved by closely matching the refractive indices at the use temperature. The alloys also show good processability, thermal dimensional stability, and economy [Stewart and Massa, 1993]. 

Polyvinyl chloride fibers with improved thermal dimensional stability in boiling water can be attained by the use of a PVC, rich in syndiotacticity, and by blending with postchlorinated PVC. Further, it is possible to prepare fiber from PVC grafted with polyacrylonitrile, which shows a softening temperature much higher than 100°C. 

Glass matrix composites, in particular with carbon fibre reinforcement, have been also proposed for a variety of applications which require thermal dimensional stability, i.e. materials with multidimensional near zero thermal expansion coefficients such as support structures for laser mirrors [21, 22]. 

The thermally stable plastics are correspondingly classified in two classes heat stable and high-temperature-stable plastics. The emphasis in heat stable plastics is on the resistance to mechanical deformation at higher temperatures. Such plastics can be applied at temperatures up to 250-300°C, whereas conventional plastics can only be used up to about 100°C. Many engineering plastics belong to the heat stable plastics (see also Section 36.4). Thermal dimensional stabilities of at least 180°C, tensile strengths of at least 45 MPa and flexural moduli of at least 2 200 MPa at this temperature with retention of at least 50% of the mechanical property values at 115° C in air for at least 11.5 years (100 000 h) are required of these polymers. In addition, the polymers should be resistant to as many chemicals as possible at temperatures of 80°C and higher. 

In comparison with thermoplasts, thermosets usually have much higher thermal dimensional stabilities (Table 36-9). They are also very resistant to creep because of the strong cross-linking. These advantages are opposed by the disadvantages of relatively low speeds of manufacture and the irreversibility of the cross-linking process. 

Glass mat rubber Rubber/ glass mat Made by mixing polymeric emulsion, precipitated silica, and rubber. This is then coated on a fiberglass mat and finally cured and dried. Finer pore diameter (<0.2 pm average), high porosity, excellent thermal dimensional stability... 

It was reported that styrenic copolymer/poIyacetal/TPU systems also have good processability and a beneficial combination of physical and chemical properties, including thermal/dimensional stability, impact resistance, chemical resistance, and creep resistance. The polymer blends are suitable for use in the preparation of a variety of molded utilitarian articles having good appearance and printability [39]. TPU/PS blends have found suitable applications as adhesive [40]. 

Chemical-binder bonding is used less frequently than thermal bonding in the production of spunbonded fabrics, and in a shift over the past decade the same is also true for staple flber nonwovens. Resin binders are occasionally used with spunbonded webs to achieve special characteristics that are unattainable thermally (38). In a typical case, acrylic resin(s) are applied to saturate the web, excess resin is removed by nip rolls, and the wet web is passed through a drying oven to remove excess water and cure the resin which tends to concentrate at flber-flber junctions. By curing the resin, a thermoset binder conveys high thermal dimensional stability to the web for applications such as rooflng. 

AutomotlV6 Applications. Aliphatic polyketones (PK-EP-6) are characterized by the following performance attributes good thermal dimensional stability, good low temperature impact behavior, and excellent resistance to fuels... 

Of the GRTP s, polycarbonate, nylon 6/10 and 6/12, polyesters, modified PPO, polyphylene sulfide, and polysulfone have superior thermal dimensional stability. 

After completion of polymerization, 0.01% (based on monomer) of Bisphenol A is added Dioctyl phthalate absorption 40% PVC has good thermal dimensional stability and color stability... 

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