Organic polymers, factors affecting

A surface is that part of an object which is in direct contact with its environment and hence, is most affected by it. The surface properties of solid organic polymers have a strong impact on many, if not most, of their apphcations. The properties and structure of these surfaces are, therefore, of utmost importance. The chemical stmcture and thermodynamic state of polymer surfaces are important factors that determine many of their practical characteristics. Examples of properties affected by polymer surface stmcture include adhesion, wettability, friction, coatability, permeability, dyeabil-ity, gloss, corrosion, surface electrostatic charging, cellular recognition, and biocompatibility. Interfacial characteristics of polymer systems control the domain size and the stability of polymer-polymer dispersions, adhesive strength of laminates and composites, cohesive strength of polymer blends, mechanical properties of adhesive joints, etc. 

Coacervation Is a very complicated physical phenomenon. And, many factors affect the properties of the resulting microcapsules. Coacervation and phase separation from organic and aqueous media Involve many properties, materials and processes such as phase Inducing agents, stirring rates, core to wall ratios, polymer characteristics, core characteristics (wettability, solubility), cooling rates and rates of addition. 

The combustion is an extremely complex process including many chemical and physical phenomena of transformation of matter. The need and desire to know and control this process urges man to study its various aspects. Organic polymers are but one example of the multitude of materials used by man. They possess peculiar features and properties which individually affect the material behavior in a critical fire situation. It is, therefore, important to study the flammability characteristics of polymeric materials and the factors affecting them. 

The control of EOF is critical to the migration time precision of the separation. Among the factors affecting the EOF are buffer pH, buffer concentration, buffer viscosity, temperature, organic modifiers, cationic surfactants or protonated amines, polymer additives, field strength, and the nature of the capillary surface. 

The physical behavior of an antioxidant is a major factor affecting its permanency, efficiency, and acceptability, especially when the polymer (e.g., fibers, films) artifact is placed directly in contact with aggressive environments, e.g., organic solvents including dry cleaning solvents, hot water and detergents, hot oils, acids, fatty food, hot air, and intense solar radiation. Physical factors, which control the permanence and efficacy of an antioxidant include distribution, solubility, diffusivity, volatility, and leachability. 

It has been recognized for some time that the kinetics of sorption of solvents into glassy polymers vary in form with the penetrant activity Fickian, anomalous, and Case II kinetics may be observed as activity is increased in a given solvent/polymer system (13). The recent study of several organic liquid and vapor penetrants in rigid PVC indicates that the the interaction parameter and plasticizing efficiency of the penetrant, as well as its activity, are factors affecting the form of the sorption kinetics (4). 

Latex-modified mortar and concrete are made by using a composite binder of inorganic cements and organic polymer latexes, and have a network structure which consists of cement gels and microfilms of polymers. Consequently, the properties of the latex-modified mortar and concrete are markedly improved over conventional cement mortar and concrete. The properties of the fresh and hardened mortar and concrete are affected by a multiplicity of factors such as polymer type, polymer-cement ratio, water-cement ratio, air content, and curing conditions. 

The ability to exfoliate and disperse the layered silicate into a polymer matrix is related to a number of factors such as the exchange capacity of the sihcate, the polarity of polymer and the chemical nature of the organic modifier. Processing conditions are one of the factors affecting the dispersion of the sihcate layers. The disappearance of the peak in the XRD patterns and the decrease of agglomerated particles in the SEM images indicate that the... 

---