Polyme coating

Ling X, Pritzker M D, Byerley J J and Burns C M 1998 Confocal scanning laser microscopy of polymer coatings J. Appl. Polym. Sc/. 67 149-58... 

FLUORINECOMPOUNDS,ORGANIC - TETRAFLUOROETHYLENE-PERFLUOROVINYLETTiERCOPOLYTffiRS] (Vol 11) PFC. See Polymer-coated fertilizers... 

To an experienced operator trained in the handling of industrial chemicals, the dimers present Httle cause for concern in handling or storage. The finished polymer coating presents even less of a health problem contact with the reactive monomer is unlikely. In the ancillary operations, such as cleaning or adhesion promotion, the operator must observe suitable precautions. Before using the process chemicals, operators must read and understand the current Material Safety Data Sheets, which are available from the manufacturers. 

J. J. Licari, Handbook of Polymer Coatings forElectronics, Noyes Pubbcations, Park Ridge, N.J., 1990, pp. 250—277. 

The author wishes to dedicate this work to Mr. T. H. Shen of Yungkoo Paint Varnish Mfg. Co., Taipei, who gave him the rare opportunity of starting a new alkyd plant as the first job assignment for a fresh college graduate, and to the memory of the late chairman of the Department of Polymers Coatings, North Dakota State University, Dr. Alfred E. Rheineck, teacher, mentor, and friend. 

Fig. 1. United States agricultural crop markets for manufactured controlled release fertilizers, 1990. (a) Total percentage ( 14 million) of market value by crop and (b) total percentage (6,800 t) of consumption by product type. IBDU is isobutyUdene diurea PCF, polymer-coated fertilizer UF,...

Fig. 6. Response of Kentucky bluegrass to polymer-coated fertilisers of select manufacturers. AppHcation of 2 lbs N/1000 ft (9.76 g/m ). A is Multicote 4...

Exxon products appear to release via a unique mechanism. Like other polymer-coated technologies, the penetration of water iato the granule is purely by diffusion. However, as water enters the particle, an osmotic pressure is created as the fertilizer is solubilized. This pressure causes an expansion of the elastomeric coating and the particle swells to many times its original diameter. As the particle swells, the coating becomes increasingly thinner to the point where it caimot contain the internal pressure and the nutrient is released. 

Nutrients are released from POLYON-coated fertilizers by osmotic diffusion. The RLC process permits appHcation of ultrathin, hence lower cost, membrane coatings which distinguishes this technology from many other polymer-coated fertilizers. The coating thickness determines the diffusion rate and the duration of release. POLYON-coated urea at a 4% coating (44% N) will release at twice the rate and will have half the duration as an 8% coating... 

Other Polymer- Coated Technologies. A number of other polymer-coated fertilizer technologies have been developed and are being ... 

Table 8. Japanese Polymer-Coated Fertilizer Technologies ...

In addition, the combination coating renders the nutrient release much less temperature sensitive than most polymer-coated fertilizers. 

The changes in the optical absorption spectra of conducting polymers can be monitored using optoelectrochemical techniques. The optical spectmm of a thin polymer film, mounted on a transparent electrode, such as indium tin oxide (ITO) coated glass, is recorded. The cell is fitted with a counter and reference electrode so that the potential at the polymer-coated electrode can be controlled electrochemically. The absorption spectmm is recorded as a function of electrode potential, and the evolution of the polymer s band stmcture can be observed as it changes from insulating to conducting (11). 

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