RIGID AND TOUGH

FIGURE 4-28 Stress-strain graph of a rigid and strong material 

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Resistance to deformation and degradation at temperatures of the order of 250°C unmatched by any other polymer of comparable rigidity and toughness. 

Properties These polymers are transparent and white. They have outstanding rigidity and toughness at low and high temperatures and also possess outstanding dimensional stability in humid atmosphere. They tend to crack under strain or on ageing. It yellows due to impurities. It dissolves in organic solvents and alkalis. 

No acetone soluble extractives were detected in completely cured resins. The films cured at 130°C for 1 hour had good rigidities and toughness as well as high transparencies. On the other hand, the resins obtained... 

Therefore, in order to increase the separation performance towards to metal ions, ABS can be introduced to a PES membrane. Among the constituent components, styrene, and 1,3-butadiene are hydrophobic, but acrylonitrile is hydrophilic. In addition, ABS contributes to the strength, rigidity and toughness of the membrane (89). 

Disulfide bridges are commonly manipulated in the process of giving hair a permanent wave. Hair is composed of protein, which is made rigid and tough partly by disulfide bonds. When hair is treated with a solution of a thiol such as 2-mercaptoethanol (HS — CH2—CH2—OH), the disulfide bridges are reduced and cleaved. The hair is wrapped around curlers, and the disulfide bonds are allowed to re-form, either by air oxidation or by application of a neutralizer. The disulfide bonds re-form in new positions, holding the hair in the bent conformation enforced by the curlers. 

PET and PBT are characterized by high strength, rigidity, and toughness low creep at elevated temperatures excellent dimensional stability low coefficient of friction good chemical, grease, oil, and solvent resistance minimal moisture absorption and excellent electrical properties. Reinforcement of these polymers with glass fibers enhances many of their properties (Table 15.16). 

Polyethersulfone Thermoplastic aromatic polymer has good heat and fire resistance, transparency, dielectric properties, dimensional stability, rigidity, and toughness, but poor solvent and stress cracking resistance, processibility, and weatherability. Processed by injection, blow, and compression molding and extrusion. Used in high temperature applications, electrical devices, medical devices, housings, and aircraft and auto parts. Also called PES. 

As seen in Table 1, DMPC/DDPC liposome could extract more proteins than egg PC/DDPC liposome. Opposite to this, however, recovery of liposome determined as lipid concentration was less in the former liposome compared with the latter one. These results are not inconsistent with those of our preliminary study [3] and suggest that efficiency of transfer of membrane proteins is deeply correlated with rigidity and toughness of liposomal membrane. 

Nylon, beside its important utility as premium fiber in the textile industry, also serves as an engineering polymer due to its unique properties of rigidity and toughness, low friction coefficient (including self lubrication), high resistance to abrasion and fatigue, supreme chemical resistance (including fire retardancy), as well as excellent thermal and electrical performance. 

Phenoxy is amorphous and transparent. It resembles, both in stmcture and properties, polycarbonate, except for the existence of the fimctional and reactive radical, OH, which may also react with di-isocyanate. Phenoxy excels in low permeability to oxygen and dimensional stability, however, it softens at 85 C. It may also crack under load, and absorb water. On the other hand, it is rigid and tough, easily processed via extrusion, injection, and blow molding at moderate temperature (200 C-270 C). Phenoxy is used in coatings and glues, as well as in some engineering applications, in spite of competition with polycarbonate. 

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