X-ray i n v c s t i g a t i o n s have bccn c a r r i c d o u t o n c r y s t a ll i n e and smectic p o l y m e r s w i t h p o l y s i l o x a n e backbones and mesog e n i c s i d e g r o u p s at.tached t o t h e main c h a i n by f l e x i b l e d l k y l s p a c e r s . F i b e r s s u i t d o l e f o r o b t a i n i n g h i g h -q u a l i t y X-ray p a t t e r n s o f c r y s t a i l i n e and s m e c t i c p h d s e s wcre produced by s t r e t c h i n g s a m p l e s , i n which case t h e mdin c h a i n s were o r i e n t c d o r , w i t h c v e n b e t t e r s u c c e s s , by aligriment o f t h c polymer s i d e c h a i n s i n a m a g n e t i c f i e l d . O r d e r e d domains w c r c d e t e c t e d f o r t h c c r y s t a ll i n e and s m e c t i c s t a t e which were d i f f c r c n t l y o r i c n t e d d e p e n d i n g o n t.he f i b e r p r o d u c i n g p r o c e d u r e . However, t h c p a c k i n g o f t h e c h a i n s w i t h i n t h e domains is u n a f f e c t e d by t h e a l i g n m e n t p r o c ed u r e . The p a c k i n g of t h e c r y s t d l l i n e p h a s e d i f f e r s l i t t l e from commonly known p o l y m e r i c s y s t e m s , dnd t h e smcctic p h a s e c a n be d e s c r i b e d w i t h t h e same k i n d o f p a c k i n g i n d less o r d e r e d s t a t e .