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# United States Patent (!9J 

# D’Alelio 

# (54] POLY\IERIZING BIS-MALEIMIDES 

(75] Inventor: Gaetano F. D’Alelio, South Bend, Ind. 

(73] Assignee: University of Notre Dame du Lac, Notre Dame, Ind. 

[21] Appl. No.: 497,490 

(22] Filed: Aug. 14, 1974 

[44] Published under second Trial Voluntary Protest Program on Mar. 23, 1976 as document No. B 497,490 

(63] Continuation-in-part of Ser. No. 363,799, May 25, 1973. Pat. No. 3,890.272. 

(51] Int. Cl.2 .............................................. C08G 73/12 

(52] U.S. Cl . .................................... 526/236; 526/258; 526/270; 526/89; 526/234; 526/256; 526/262 

(58] Field of Search .................. 526/258; 260/78 UA, 260/47 UA, 47 CZ, 47 CP, 65, 326 R, 326 S, 326 NS, 329 AM, 333, 79.7, 88.5 A, 88.3 A 

## [56] References Cited 

<img src='content_image/946048.jpg'>

## Related U.S. Application Data 

## U.S. PATENT DOCUMENTS 

<img src='content_image/946049.jpg'>

Lubowitz, New Polyimides Polymers and Composites Conference on High Temperature Polymers, Rein› forcements and Composites, University of Utah, Jun. 8 to 13, 1970. 

Primary Examiner-Lester L. Lee 

Attorney, Agent, or Firm-Michael, Best & Friedrich 

## [57] ABSTRACT 

Processes for increasing the molecular weight of bis› maleimides are provided. The bis-maleimides are re› acted with certain cyclic dienes to form reversible ad› ducts. These adducts, upon elimination of the cyclic diene, yield an extension of the bis-maleimides to higher molecular weight polymers, ultimately to thermally stable, infusible polymers. The process can be inter› rupted to yield tractable polymers which are also con› vertible to cross-linked, infusible products. Modifica› tions of the process include preparing the adducts in the presence of aprotic solvents as well as Bronsted acid salt catalysts, and the isolation of intermediate solid prod› ucts. 

## OTHER PUBLICATIONS 

## 15 Claims, No Drawings 

# (11] B 4,118,377 

# (45] Oct. 3, 1978 

