Hybrid Graft Polymers and Plastics 



Basic studies on the free radical and other 

 chemical combinations of organic and inorganic 

 monomers with starch, leather, and other natural 

 polymeric agricultural products have provided 

 new classes of hybrid polymers, complex mole- 

 cules, and plastics with a wide range and diversity 

 of useful properties. Some of these unique materi- 

 als have found commercial application. One such 

 derivative, starch xanthate, can provide a means 

 for slow release of pesticides, can be used to 

 make powdered rubber by an energy-saving pro- 

 cess, and one form of the substance can be used 

 to reduce toxic levels of metals such as lead, zinc, 

 silver, copper, and cadmium in industrial waste 

 water. The combination of acrylonitrile and starch 

 has produced a material — the so-called "super 

 slurper" — that can fix large quantities of water in 

 fluid-control applications, ranging from diapers and 

 bandages to firefighting and sandy soils. Another 

 grafting reaction, the combination of leather with a 

 long chain amino acid, converts leather into a dry- 

 cleanable product. 



Gugliemelli. I,. A., C. 1.. Swanson, and W. M. Doane 197.^. 

 Kinetics of Grafting Acrylonitrile onto Starch. J. Polym. Sci. 

 I 1(10): 2461-67. 



Weaver, M. O.. G. K. Fanta, and W. M. Doane. 1974. Highly 

 Absorheni Starch-Base Polymer. Tech., Sym, Nonwoven 

 Prodiicl Tech.. INDA. March ."^-6, 1974, pp 169-177. 



Precombustion Pyrolysis 



Studies of precombustion pyrolysis have de- 

 fined the various chemical pathways by which 

 heated wood degrades into simpler flammable and 

 nonflammable substances before igniting. This 

 knowledge has enabled chemists to devise more 

 eflFective fire retardants by selecting chemicals 

 that shift precombustion pyrolysis reactions in the 

 direction of higher relative yields of nonflammable 

 products. 



Broido, A., Y. Houminer, and S. Patai. 1966. Pyroiitic reac- 

 tions of carbohydrates. Part I. Mularotation of molten d-glu- 

 cose. J. Amer. Chem. Soc.,41 1-414. 



Broido, A. 1966. Thermogravimetric and differential thermal 

 analysis of potassium bicarbonate contaminated cellulose 

 Western Stales Section Combustion Institute. Denver, Colo. 



Briodo, A. and M. Weinstein, 1970. Thermogravimetric Analy- 

 sis of Ammonia-Swelled Cellulose. Combustion Science and 

 Technology, l::79-2S.'5. 



Broido, A., A. C. Javier-Son, and E. M. Barrall. II. 1973 

 Molecular weight decrease in the early pyrolysis of crystalline 

 and amorphous cellulose. J. Polymer Science, I7:.'t627-36.1-'^. 



Shafizadeh, F., G. D. McGinnis, R. A. Susott, and C. W. Phil- 

 pot. 1970. Solidstate transition of 1,6-anhydro-B-D-glucopyra- 

 nose. Carbohydrate Research, 13:184-186. 



Shafizadeh, F., G. D. McGinnis, R. A. Susott, and C. W. Phil- 



pot. 1970. Thcrniodynaniic properties of 1 .6-anhydrohexo- 

 pyranose crystals. Carbohydrate Research. I.^i: I6.S-I78. 



Shafizadeh, F., C. W. Phllpot, and N. Ostojic, 1971. Thermal 

 analysis of 1 .6-anhydro-B-D-glucopyranose. Carbohydrate 

 Research. 16:279-287. 



Fire Spread 



Research on the mechanisms of fire spread in 

 finely divided forest fuels led to the development 

 of the first universally applicable prediction sys- 

 tem for the rate of fire spread based on first princi- 

 ples of heat transfer. This model forms the basic 

 framework for the National Fire Danger Rating 

 System to optimize the efl'ectiveness of the wild- 

 lands firefighting efforts of Federal and State agen- 

 cies, a $250 million annual cost to the public. 



Rothermel. R. C. 1972. A mathematical model for predicting 

 lirespread in wildland fuels. USDA, Forest Service Research 

 Paper. INT-ll.'i. 40p. 



Principles for Mechanically Harvesting Fruits 

 and Vegetables 



Basic to the development of mechanized har- 

 vest systems for fruits and vegetables has been 

 the study and understanding of such areas as the 

 biophysical properties of selected fruits and vege- 

 tables, forces effecting detachment from tree or 

 plant, detection of crop maturity, elTect of me- 

 chanical forces on product quality, and chemicals 

 to promote even ripening and reduce detachment 

 forces. Such research has already led to the de- 

 velopment of mechanical harvest systems for a 

 number of fruit and vegetable crops. 



Coppock. G. E., S. I.. Hedden and H. Lenker. 1969. 

 Biophysical properties of citrus fruit related to mechanical 

 harvesting. Transactions ASAE. 12:561-563. 



Diener. R. G., J. H. Levin, and B. R. Tennes. 1968. 

 Directional strength properties of cherry, apple and peach bark 

 and the influence of limb mass and diameter on bark damage. 

 Transactions ASAE. 12:788-791. 



Diener, R. G.. J. H. levin and W. A. Bradley. 1969. Seasonal 

 changes in creep, relaxation, elasticity and damping of live 

 apple-tree limbs (properties affecting mechanical harvesting). 

 Transactions ASAE. 12:137-140. 



Fridley, R. B.. R. A. Bradley, J. W. Rumsey and P. A. Adri- 

 an. 1968. Some aspects of elastic behavior of selected fruits. 

 Transactions of the ASAE. 1 1:46-49. 



Gillespie, B. A.. T. Liang and A. L. Myers. 1975. Multiple 

 spectral analysis for tree-shaker parameter optimization. 

 Transactions of the ASAE. 18:227-2.30, 1975. 



Lenker. D. H. and S. L. Hedden. 1968. IJmb properties of 

 citrus as criteria for tree-shaker design. Transactions ASAE. 

 11:129-131. 



Lenker. D. H, and P. A. Adrian. 1971. Use of X-rays for se- 

 lecting mature lettuce heads. Transactions of the ASAE. 

 14:894-898, 1971. 



Marshall. D. E.. J. H Levin and B. Cargill. 1971. Properties 



AGRICULTURE 17 



