Many different species of fungi 

 have been associated with defacement 

 of organic coatings. However, one 

 species, Aupeobasidi-vm Tpullulans 

 (formerly reported as Pultavta 

 pullulans) has been reported [1] to 

 predominate. This species (Figure 1) 

 is, thus, the one most frequently 

 used in laboratory studies. 



SYNTHESIS OF ORGANOTIN PRODUCTS 



Figure 1 . 



Hyphae and groups of 

 conidia (spores) on young 

 colony of Aureobasidium 

 pullulans. 



The synthesis of the organotin 

 products was a modification of the 

 method used by Dyckman and Montemar- 

 ano [5,6] in preparing tin- containing 

 acrylic resins. In this modification 

 bis (tri-n-butyltin) oxide, hence- 

 forth called TBT0, a was reacted with 

 the carboxyl groups in free acids or 

 in drying oil alkyd resins. 

 In order to study the basic reaction, experiments were first con- 

 ducted with phthalic acids. In separate experiments 0.1 mole of ortho- , 

 iso-, and terephthalic acid were dissolved (as far as possible) in hot, 

 dry benzene (200 ml) in a 1,000-ml, 3-necked flask, and 0.1 mole of TBTO 

 dissolved in dry benzene was then added through a separatory funnel. An 

 immediate reaction was noted by rapid boiling of the benzene, increased 

 solution of the phthalic acid, and collection of water distilled azeotrop- 

 ically from the reaction flask. The 0.1 mole of water removed by such 

 distillation was collected in a calibrated distillation receiver. 

 Removal of benzene by distillation allowed crystallization of the iso- 

 and tere- reaction product. The melting point of the tere- product was 

 near that (78°C) reported by Dunn and Norris [7], and the iso- product 

 was 50 C after recrystallization from benzene. These authors report 

 that the ortho- product was a liquid but did not report preparation of 

 the iso- product. 



Five alkyd resins with varying acid numbers and the free fatty 

 acids from linseed oil were reacted separately with TBTO using the above 

 procedure to yield the products listed in Table 1 . The acid numbers 

 were first determined by Federal Test Method 5072 [8] (ASTM D1639-70 

 [9]), and the total solids were determined by Federal Test Method 4041 

 [10] in order to determine the calculated amount of TBTO for complete 

 reaction. In all cases, the calculated amount of water formed in the 

 reaction was collected by azeotropic distillation. The total solids 

 content and the percent tin (determined by atomic absorption spectropho- 

 tometry) of each product were consistent with the calculated tin values 

 in Table 1. Also, analyses by M and T Chemicals, Inc. of reaction 



1 



TBTO is the registered name of M and T Chemicals, Inc., for this product. 



