Organic reinforcing agents

Lin et al. [194] found that reinforcement of polyurethane elastomer with wholly rigid aromatic m-phenylene isophthalamide block copolymers results in glass transition temperatures below 0%. Such block copolymers have improved the reinforcing effect, which is reflected in both their tensile strength and elongation when compared with virgin polyurethane. 

Evrard et al. [195] evaluated powdered polyamides of different types as sani-reinfoicing fillers in carboxylated nitrile rubber. They evaluated the filler vulcanizates for tensile properties, tear strength, coefficient of friction, filler matrix adhesion, and swelling in various fluids. 

Dynamic mechanical analysis has also been used to determine the mechanical and thermal properties of low-density polyethylene and ethylene-propylene-diene terpolymer containing jute filler, which had improved flexural and impact properties compared to those of the base polymer [198]. Jeong and coworkers [196] and others [195] investigated the dynamic mechanical properties of a series of polyhexamethyl-ene lerephthalale, poly(l,4-cyclohexylenedimethylene terephthalate), and random copolymers thereof in the amorphous state as a function of temperature and frequency. The effect of copolymer composition on dynamic mechanical properties was examined and the dynamic mechanical properties interpreted in terms of the cooperativity of segmental motions. 

---

Resins resulting from the polymerisation of one of the fractions of coal tar. Used as processing aids, tackifiers and as non-black organic reinforcing agents in mbber compounding. 

Reinforcing agents (CB, talc, silica, and other organic and fibrous filler)... 

An activator in rubber compounds containing organic accelerators. In polychloroprene, zinc oxide is considered to be the accelerator rather than the activator. The use of zinc oxide as a reinforcing agent and as a white colouring agent is obsolescent. Zinc oxide is manufactured by either the French (or indirect) process or by the American (or direct) process. It can be used as a filler to impart high thermal conductivity. 

Basically a plastic composite is the assembly of two or more materials made to behave as a single product. Examples include vinyl-coated fabric used in air mattresses or laminated metal bonded together with a plastic adhesive used in helicopter blades. The RP type of composite combines a plastic with a reinforcing agent that can be fibrous, powdered, spherical, crystalline, or whisker, made of organic, inorganic, metallic, or ceramic material. To be structurally effective, there must be a strong adhesive bond between the resin and reinforcement. 

Use Glass, ceramics, iron-free aluminum and aluminum salts, manufacture of activated alumina, base for organic lakes, flame retardants, mattress batting. Finely divided form (0.1-0.6 microns) used for rubber reinforcing agent, paper coating, filler, cosmetics. 

Reinforcing agents mineral or organic filler particles, glass microspherea mica flake , whiskers composites... 

Kevlar is another important fibre which is largely used as a reinforcing agent for many polymer-based composites. It is obtained by the condensation polymerisation of terephthalic acid with p-phenylenediamine. It exhibits lyotopic liquid crystalline behaviour and therefore has high strength, stiffness, modulus and thermostability. As it is also an organic polymer, its compatibility with other polar polymeric matrices is very good. 

The composites can be classified on the basis of the form of their structural components fibrous (composed of fibers in a matrix), laminar (composed of layers of materials), and particulate (composed of particles in a matrix). The particulate class can be further subdivided into flake (flat flakes in a matrix) or skeletal (composed of a continuous skeletal matrix filled by a second material). In general, the reinforcing agent can be either fibrous, powdered, spherical, crystalline, or whiskered and either an organic, inorganic, metallic, or ceramic material. 

---