14 Use of the Graded Gel Block in Evaluating PVC Plastisols S . W . CRITCHLEY, A. HILL, a n d C. P A T O N
Downloaded by UNIV OF LIVERPOOL on December 5, 2015 | http://pubs.acs.org Publication Date: January 1, 1965 | doi: 10.1021/ba-1965-0048.ch014
The Geigy Co., Ltd., Simonsway, Manchester, England
Following a review o f past w o r k , this article d e s c r i b e s the "Graded G e l B l o c k , " a new c o m mercially available instrument designed t o e v a l u a t e t h e s e l l i n g c h a r a c t e r i s t i c s of p o l y v i n y l c h l o r i d e p l a s t i s o l s . This i n s t r u m e n t a l l o w s t h e v a r i o u s s t a g e s of p l a s t i s o l g e l a t i o n t o b e f o l l o w e d a t and b e y o n d t h e l i q u i d - s o l i d transit i o n a n d f a c i l i t a t e s the p r e d i c t i o n of the m i n i mum t e m p e r a t u r e n e c e s s a r y t o a t t a i n a d e quate physical properties. Plasticizers studied a n d r e p o r t e d b y way of e x a m p l e s of the t y p e s of i n v e s t i g a t i o n p o s s i b l e w i t h t h e i n s t r u m e n t include dialkyl p h t h a l a t e s , a triaryl p h o s p h a t e a n d t h e d i i s o o c t y l e s t e r s of a s e r i e s of a l i p h a t i c dicarboxylic adds.
yhe first commercial use of a polyvinyl chloride (PVC) plastisol in the United Kingdom was in 1941 when ICI (Hyde), Ltd. made its first sale of leather c'oth to the London Passenger Transport Board for the reupholstering of London bus seats. By the end of World War II, the Distillers Co. had developed a paste grade PVC process which contributed to an agreement with B. F. Goodrich Chemical Co. ard the formation in 1946 of British Geon, Ltd., whereby production of Goodrich developed suspension polymers and the Distillers' paste polymer Geon 121 was started in 1948. It is surprising therefore that after such a lapse of time, we should consider it interesting to discuss laboratory techniques for the study of the effect of temperature on the properties of PVC plastisols. Although this article is mainly concerned with the liquid/solid transition temperature and the effect of increasing temperature on the tensile properties of the solid state, we recognize the importance of studies on the effect of increasing temperature on the viscosity of the liquid plastisol. The latter studies, which indicate the well known initial lowering of viscosity followed by a rapid rise in viscosity, have an important bearing on the use of PVC pastes for such applications as rota146
In Plasticization and Plasticizer Processes; Platzer, N.; Advances in Chemistry; American Chemical Society: Washington, DC, 1965.
Downloaded by UNIV OF LIVERPOOL on December 5, 2015 | http://pubs.acs.org Publication Date: January 1, 1965 | doi: 10.1021/ba-1965-0048.ch014
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CRITCHLEY ET A L
Graded Oml Block
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tional casting and the coating of heated articles by dipping. Furthermore, it is recognized that the temperature at which the viscosity/temperature curve approaches the vertical bears some relation to the liquid/solid transition temperature. Such studies have been made by Todd, Esarove, and Smith (0), Alter (/), Bauer (£), Newton and Cronin (
