Synthesis of Polyimides derived from 2 , 6-diamino-4-methyl-1 , 3 , 5-triazine

This work included synthesis of several new polymers of polyacryloyl chloride in two steps . The first step the included the reaction of N-( sub. or un sub. benzoyl and sub. or un sub. acetyl ) amidyl sub. 2,6diamino -4-methyl-1,3,5-triazine (1-5) by condensation of many substituted acid chlorides with 2,6diamino -4methyl-1,3,5-triazine . While the second step included the reaction of polyacryloyl chloride with the produced compounds (1-5) in step (1) in the presence amount triethyl amine (Et3N) to obtain new polyimides (6-10). The prepared compounds were characterized by UV. , FT-IR, and some of them by 1 H-NMR and 13 CNMR spectroscopy.


Introduction:
Triazine derivatives are used in pharmaceutical industry as coupling agents for the synthesis of peptides and as side chain of antibiotics , as well as in formulating bactericides and fungicides [1][2].
1,3,5-triazine are amongst the oldest known organic molecules ; originally they were called the symmetric triazines usually abbreviated as s. or syn-triazines [3].Som of the substituted 1,3,5-triazine have reported to possess interested biological activities [4].wide range of 1,3,5-triazines exhibit selective their bicidal properties , such as anticancer, antiviral [5], bactericidal , fungicidal [6], antimalariol agents and antituberculosis [7].One of the most important derivatives of 1,3,5-triazine is 2,4-diamino-6-methyl-1,3,5-triazine that has played an important role in organic chemistry [8].It is used as an intermediate for pharmaceuticals and as a modifier and flexibizer of for maldehyde resins [9], which reacted with sub. or unsub.benzoyl and sub.or unsub.acetyl to give N-( sub. or unsub.benzoyl and sub.or unsub.acetylamidyl sub. 2,4-diamino-6-methyl-1,3,5triazine , which reacted with poly acryloyl chloride to give new poly imides derivatives for 2,4-diamino-6methyl-1,3,5-triazine.Polyimides (PIS) are classifided as a group of superenginecring plastics owing to their excellent thermal stability [10], and they are a class of highperformance representative and involving aromatic and hetero cyclic rings in the main chains that are well known as heetresistant organic materials.Polymers have been widely used in flexible displays [11].Like Polymer electronic memories, prevaporation, biofuels speparation and many other fields of microelectronics [12], optics , a erospace industries and biomedical engineering [13].However polyimide materials are usally difficult to be processed because of their infusibility at high temperature and insolubility in most organis solvent [14].inorder to improve the solubility and melting ability of polyimides, many studies have been focused on introducing the fluorocontaining groups, or flexible group into the polymer backbone [15].

Materials and Methods:
All chemicals used in this work from BDH , Merk and Fluka were used without further determination .

Table (3): FT-IR spectral data for all product compounds
Comp. No.

Results and Discussion:
The present work involved two steps, The first step includes the preparation of new five amides (1-5)that were prepared by the reaction of 2,4-diamino-6methyl-1,3,5-triazine with different substituted acid chlorides.The synthesis of these compounds was carried out lined in scheme (1).The starting material for the synthetic polyimides is 2,4-diamino-6methyl-1,3,5-triazine which condensed with different substituted acid chlorides through nucleophilic substitution of chloride with amino group lead to amides (1-5) (Scheme 2) .
The second step: included the of preparation new five polyimides (6-10) that were prepared by the reaction of amides (1)(2)(3)(4)(5) in the first step with polyacryloyl chloride subjected to another nucleophili substitution by treating with poly acryloyl chloride using triethyl amine (Et 3 N) as catalyst.The mechanism of reaction involves a nucleophilic attach on the carbonyl as shown in Schemes (3) [14].The FT-IR spectrum showed the disappearance of amide bands υ(N-H) , υ(C=O) , with appearance bands at (1716) cm -1 attributed to (C=O) amide as shown in Table (3) Figure (6) Another evidence for compounds (7) and ( 9) its , 1 H-NMR spectrum that showed different signals , two multiplet at (1.799-1.976)ppm and (2.753-2.792)ppm as signals for ethylene ( acryl ) protons as shown in Figure (13) and (15).