Reporter:Chen-Kun Lin

Adviser:Cheng-Chien Wang

2011.03.18

Epoxy resins are widely used as coatings,adhesives,primers, semiconductor encapsulation and as matrices for advanced fibre-reinforced composites.

Epoxy resin systems can be rendered fire retardant either by the incorporation of fire retardant additives (e.g. triphenyl phosphate ,decabromo diphenylether, aluminium ethyl phosphinate ) or by copolymerisation with reactive fire retardants (e.g. diglycidylether of tetrabromobisphenol A ).

Introduction

Among non-reactive compounds containing phosphorus, derivatives of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)were shown to induce especially excellent flame retardant properties in both neat epoxy systems and their fibre-reinforced counterparts.

Introduction

ExperimentalPreparation of neat epoxy formulations

DGEBA was placed in a glass flask and heated to 80–90 ℃using an oil bath connected to a temperature controller.DGEBA was placed in a glass flask and heated to 80–90 ℃using an oil bath connected to a temperature controller.

The desired amount of the given hardeners was added slowly to the resin and subsequently the suspension was mixed using a mechanical stirrer operating at 600–1300 rpm until the compounds were dissolved and the mixtures were clear again.

The desired amount of the given hardeners was added slowly to the resin and subsequently the suspension was mixed using a mechanical stirrer operating at 600–1300 rpm until the compounds were dissolved and the mixtures were clear again.

During mixing the temperature was kept constant at 80– 90 ℃.During mixing the temperature was kept constant at 80– 90 ℃.

60 vol.% of carbon fibres

Experimental

Experimental

Following the mixing procedure, the hot mixtures were poured into a preheated aluminiummould at 80 ℃.Following the mixing procedure, the hot mixtures were poured into a preheated aluminiummould at 80 ℃.

All epoxy formulations were cured as follows: the curing cycle started with a 2 ℃ min-1 rise from room temperature to 180 ℃.All epoxy formulations were cured as follows: the curing cycle started with a 2 ℃ min-1 rise from room temperature to 180 ℃.

This temperature was maintained for 2 h and curing was completed with a 2 ℃ min-1 climb from 180 ℃ to room temperature.This temperature was maintained for 2 h and curing was completed with a 2 ℃ min-1 climb from 180 ℃ to room temperature.

Evaluation of the decomposition behaviour& fire behaviourEvaluation of the decomposition behaviour& fire behaviour

Results and discussionDecomposition mechanism of the neat epoxy formulations

Results and discussionFire behaviour of the neat resin formulations andof the carbon fibre-reinforced composites

Results and discussionFire behaviour of the neat resin formulations andof the carbon fibre-reinforced composites

When 2 was substituted for DDS as a hardener for the neat epoxy resin system, the LOI was improved significantly; an increase of about 13% was achieved with a phosphorus content of 4.5 wt.%.

A similar impact on flammability was also achieved for the composite based on DGEBA/DDS/2 with 60 vol.% carbon fibres and an overall phosphorus content of only around 1 wt.%. The LOI of the composite DGEBA/DDS/2 was increased by 17% and the UL 94 improved to a V-1 classification from the HB for the analogous DGEBA/DDS composite.

Conclusions

Addition of 1 the PHRR and the THE were improved crucially due to flame inhibition,whereas the charring induced in the DGEBA/DDS/2 composites could not be exploited with respect to PHRR and THE.

The incomplete combustion led to an increase in total smoke release (TSR) and in CO production.

Conclusions

實驗報告

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