環氧樹脂摻混磷酸鹽系難燃劑之熱裂解行為與耐燃性質研究

Abstract

本論文研究的目的在於探討epoxy / melamine phosphate ( MP )、epoxy / Imidazole / MP 及epoxy / DICY / MP三種摻混組合，配合四種不同的硬化時間及溫度所製作出的A、B、C、D及E五系統的熱裂及熱氧裂解機構，並討論氧氣對裂解的影響及其所扮演的角色。藉由的裂解曲線圖，可得知隨溫度的升高，難燃劑MP於260 ℃產生裂解，所釋放出的磷酸在與環氧樹脂產生化學反應，也因而導致環氧樹脂的安定性下降，進而促使環氧樹脂脫水裂解，形成致密的膨脹型焦炭層，此為其主要的難燃機構。因此，環氧樹脂在此扮演了焦炭層的主要生成者，這點與以往文獻中有關膨脹型難燃系統的作用機構不同。 為了進一步確認並比較各摻混系統間的難燃性質及機械強度，極限氧指數( LOI )及接著強度，皆於本研究中作一探討。結果顯示，不論在何系統，當摻混5 phr MP時，即可獲得良好的耐燃效果( LOI ＝ 29 )，而在模擬經歷惡劣環境後，測試各系統之接著強度，發現仍保有不錯的接著強度，顯見其耐候性良好。 綜合所有的研究結果，我們得知以MP作為此膨脹型難燃系統的難燃劑，確實可以大幅提升環氧樹脂的耐燃性質。比較各組的機械強度，epoxy / melamine phosphate ( MP )、epoxy / Imidazole / MP 摻混組合比epoxy / DICY / MP摻混組合好。且當MP添加的量達30 phr時，所獲得反應放熱焓最大且拉力強度最好，耐燃性質及耐候性質亦優，藉此結果，我們計算出MP上可與環氧樹脂產生反應的有效官能基數為3 ~ 4。

We have studied the thermo and thermooxidative degradation of epoxy ( BE 188 ) / melamine phosphate( MP ), epoxy / imidazole / MP and epoxy / DICY / MP blends with four curing schedual and shown the influence of oxygen in the degradation mode. It shows that a chemical interaction is shown to take place between melamine phosphate ( MP ) and epoxy( BE188 ) on heating , resulting in decreasing the stability of the virgin polymer and implies a protection mechanisms leading to the intumescence. To evaluate the flameability properties of the materials, limit oxygen index ( LOI )and tensile strength , were assessed in experiments. The results showed that the intumescent fire retardant filled epoxy has superior flameability properties and keeps good retention of adhesive strength after harsh environmenttal test . It is concluded that this intumescent system additive is an effective flame retardant on improving combustion properties for epoxy.By tensile strength we got epoxy ( BE 188 ) / melamine phosphate( MP ), epoxy / Imidazole / MP blends are stronger than epoxy / DICY / MP blend and in that case we also got the strongest tensile strength as epoxy filled 30 phr MP, by this result ,we calculate that MP has a functionality of 4 toward epoxy BE188 might be 3∼4 .