Benzoxazine resin and their nanostructured composites cure kinetic by DSC

  • PDF / 213,580 Bytes
  • 6 Pages / 584.957 x 782.986 pts Page_size
  • 16 Downloads / 204 Views

DOWNLOAD

REPORT


ichelle Leali Costa Materials and Technology Department, São Paulo University (UNESP), Guaratinguetá, São Paulo, Brazil 12516-410; and Materials Division, Institute of Aeronautics and Space, São José dos Campos, São Paulo, Brazil 12228-904 (Received 28 July 2013; accepted 15 October 2013)

Benzoxazine resins are a new class of thermosetting phenolic resins that have emerged in recent decades, overcoming the traditional properties of epoxy and phenolic resins applied in the aerospace industry. The incorporation of low mass concentration of carbon nanotube (CNT) in polymer matrices can produce structural materials with superior properties. Thus, this work aims to prepare nanostructured composite benzoxazine resin/CNT and to evaluate the cure kinetic study by differential scanning calorimetry of neat benzoxazine resin and their nanostructured composites produced. Calculations of the activation energy, the reaction order, and kinetic constants are performed by a nonisothermal procedure. In general, it was observed that CNTs act as catalysts for curing the benzoxazine matrix without affecting the initial and final cure temperatures. I. INTRODUCTION

In recent years, high temperature resistant polymers have been developed with the purpose of being used in various applications such as microelectronic component insulator and internal aerospace structures. Among the many examples of high temperature resistant thermosetting polymers which are being marketed, epoxy resins, phenolic resins, bismaleimide, and polyimide may be mentioned.1–4 Benzoxazine resins are a new class of thermosetting phenolic resins that have emerged in recent decades, exceeding the properties of the traditional epoxy and phenolic resins that are applied in the aerospace industry. The benzoxazines combine the thermal properties and flame retardancy from phenolic and epoxy mechanical properties. They are considered high-performance polymers with high temperature resistance, dimensional stability, good electrical properties, high glass transition temperature, low moisture absorption, flame retardant, do not require catalysts, do not generate subproducts during the cure, and can be stored at ambient conditions.2–6 This polymer has been reported to present high glasstransition temperature (Tg) and high modulus. Some properties of polybenzoxazine exceed many epoxy resin, as well as conventional phenolics. Recently, several US patents have been issued on the applications of the benzoxazine compound a)

Address all correspondence to this author. e-mail: [email protected] DOI: 10.1557/jmr.2013.327 3094

J. Mater. Res., Vol. 28, No. 22, Nov 28, 2013

http://journals.cambridge.org

Downloaded: 20 Feb 2015

or resin that has utility especially for use within semiconductor fabrication industry. Moreover, the use of the resin as a matrix for highly filled composites has been achieved. Furthermore, the ability of benzoxazine resin to alloy with other polymers provides the resin with even broader range of applications.7 The benzoxazines were first synthesized in 19