Industrial Polyblends

Cellulose is an old polymer with new industrial applications. The derivatization of cellulose has opened up tremendous production and marketing possibilities for the adhesives industry. Various important adhesives have been derived from cellulose ethers. The structure and molecular size of cellulose and their influence on swelling and solubility are important considerations in the preparation of cellulose derivatives for adhesive applications. Modern cellulosic adhesives derived from grafted copolymers and polyblends are also proving very useful. 

The impact resistance of polypropylene at low temperature has been improved by polyblending with EPDM or E-P rubber to make possible the application of this material in the automotive industry. The low-temperature properties of polyamides such as nylon 6 and nylon 66 have been improved by polyblending with ethylene copolymers or specially grafted polybutadiene (45). 

This year s U.S. production of thermoplastics, thermosets, and synthetic rubber is expected to be 29 billion pounds. About 80% of this is based on only a few common monomers. To improve performance, the polymer industry rarely changes to a new, probably more expensive polymer, but instead it shifts from mere homopolymers to copolymers, polyblends, or composites. These three types of multicomponent polymer systems are closely inter-related. They are intended to toughen brittle polymers with elastomers, to reinforce rubbers with active fillers, or to strengthen or stiffen plastics with fibers or minerals. 

Many industrial developments regarding polyblends, as well as a great deal of fundamental research, concern the so-called "rubber toughened plastics" In fact, most thermoplastic polymers widely... 

Lanco Gidd 5118 Lanco Glidd 5618 MkroKlear 418 SIwet L-7622 lubricait, industrial finishes Aqua Poly 225 GP-218 Slcone Polycl Copolymer Microspersion 120- Mkrospersion 190-50 Mkrosperskm 214-50 Polyblend 100XF Polyfluo 120 Polylluo 150 Polyfluo 190 Polyfluo 200 Polylluo 302 Po uo 400 Polyfluo 523XF Polylluo 540 Polysik 14 Polysik 600 Polysit 750 lubricant, industrial ol ... 

Modem technical data also include many dynamic properties obtained by measurements over a wide spectrum of frequencies and temperatures, in addition to data on mechanical properties in a wide range of times and rates. Quite often the data may be described by a master curve providing extremely widely applicable information with some sacrifice of accuracy. On the other hand in most cases, the material consists not only of a single polymer but of a host of additives and modifications. At present there is much use of copolymers in a variety of compositions (including blocks and grafts), polyblends, composite systems and many stabilizers and additives. In practice, a giant additives industry has been developed along with the resin industry. 

Polyblends and alloys (compatible systems) introduced a new dimension to the world of polymers, leading to a significant saving by avoiding the manufacture of new polymers or copolymers. These are industrial mixtures that combine certain properties and thus often reduce the cost of the product. When compatibility is reached, division into separate phases is eliminated (which may reduce mechanical properties). Therefore the use of compatibiliz-ers as coupling agents has been increased. In the ideal case of compatibility... 

Equation-5, X and Phi denote the molar and volume fiaetion of the components, respectively. Eor two polymers to be miscible, the free energy of mixing must be negative. If the solubility parameters of the polymer pairs are too far apart, the free energy of mixing becomes positive, and compatibilizers are often needed to reduce the interfacial tension between incompatible components in a blend. In industry, both miscible and immiscible polyblends are important materials because they fill (filFerent market needs. 

Polybutadiene based polyblends (Table 3.19) are very important plastics with industrial applications, e.g. impact resistance polymers and impact modifiers for rigid poly(vinyl chloride). These polyblends are very susceptible to photo-oxidative degradation, because of the presence of polybutadiene. Intensive studies of the photo-oxidation of the rubber modified polyblends lead to the following conclusions [761-764, 1936] ... 

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