Low-melt Viscosity Polyimide Resins for Resin Transfer Molding (rtm) Ii

Content Provider	Semantic Scholar
Author	Chuang, Kathy C. Criss, Jim McRae Mintz, Eric A. Scheiman, Daniel A. Nguyen, Baochau N. McCorkle, Linda
Copyright Year	2007
Abstract	ABSTRACT A series of polyimide resins with low-melt viscosities in the range of 10-30 poise and high glass transition temperatures (T g ’s) of 330-370 °C were developed for resin transfer molding (RTM) applications. These polyimide resins were formulated from 2,3,3’,4’-biphenyltetracarboxylic dianhydride (a-BPDA) with 4-phenylethynylphthalic anhydride endcaps along with either 3,4’-oxyaniline (3,4’-ODA), 3,4’-methylenedianiline, (3,4’-MDA) or 3,3’-methylenedianiline (3,3’-MDA). These polyimides had pot lives of 30-60 minutes at 260-280 °C, enabling the successful fabrication of T650-35 carbon fiber reinforced composites via RTM process. The viscosity profiles of the polyimide resins and the mechanical properties of the polyimide carbon fiber composites will be discussed. KEY WORDS: Polyimide, Low-melt Viscosity, High Temperature Composite, RTM370, Resin Transfer Molding, RTM, Biphenyl Dianhydride, a-BPDA 1. INTRODUCTION High temperature polymers have been used as lightweight composite materials for aerospace applications for decades. Polyimides, especially, play an important role for higher temperature applications beyond the capability of epoxies (177 °C) and bismaleimides, BMI, (232 °C) [1]. Most notably, PMR-15 [2] polyimide was successfully fabricated into a composite outer bypass duct for F-404 engine as a replacement for the titanium duct, leading to 30% cost savings and 12% weight savings. Under NASA’s High Speed Civil Transport (HSCT) program, PETI-5 [3] was investigated extensively for airframe application during the1980s [4]. However, both PMR-15 and PETI-5 polyimide composites require the use of prepregs or tow-pregs as well as labor intensive hand lay-up for fabrication of complicated geometries and structures. In addition, the use of organic solvents, such as methanol or N-methyl-2-pyrrolidinone (NMP), can be difficult to remove and have adverse health and safety issues during processing. In recent years, efforts have concentrated on the development of solvent-free, low-melt viscosity (10-30 poise) polyimide resins that can be adapted to low-cost resin transfer molding (RTM) or resin infusion (RI) processes. ______________________________________________________________________________ * This paper is declared a work of the U.S. government and is not subjected to copy right protection in the United States.
File Format	PDF HTM / HTML
Alternate Webpage(s)	https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070011454.pdf
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article