화학공학소재연구정보센터
Polymer(Korea), Vol.26, No.4, 452-461, July, 2002
폴리아미드 6의 열 산화반응에 의한 황변 현상과 산화방지제의 효과
Discoloration and the Effect of Antioxidants on Thermo-Oxidative Degradation of Polyamide 6
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초록
본 연구에서는 폴리아미드 6 (PA 6)을 70∼160 ℃에서 장시간 사용하였을 때 산화방지제의 사용유무 및 농도에 따른 열 안정성을 조사하였다. 70∼160 ℃의 온도범위내의 열 산화반응 시 모든 시료는 100시간 내에 황변 현상이 일어났다. 기계적 물성, 황변 지수, 점도측정으로 가장 적정한 산화방지제의 농도를 조사하였다. 일, 이차 산화방지제의 조성변화에 의한 산화방지효과는 미미하였다. 황변 현상의 분석은 NMR, IR, 그리고 element analysis (EA)를 사용하였다. 13C NMR에 의해 서로 다른 카르보닐기의 존재를 확인하였으며, 산소의 소모량 측정은 EA를 사용하였다. Arrhenius식을 이용하여 산화방지제를 첨가한 시료와 그렇지 않은 시료의 lifetime을 예측하였다.
In this study, the effect of various concentrations of antioxidants on thermo- oxidative degradation of polyamide 6 was investigated. Unstabilized and stabilized polyamides 6 were subjected to long-term oven aging in ambient atmosphere at 70∼160 ℃. All of specimens were discolored within 100 hr at temperature range of 70∼160 ℃. Optimum antioxidant concentration was determined from the data of mechanical properties, yellowness index and relative viscosity. The synergistic effect of each primary and secondary antioxidant concentrations was not observed. Yellowing phenomenon was explained by using NMR, IR and EA. Different carbonyl groups were detected by 13C NMR. During thermooxidative degradation, oxygen consumptions were determined by EA. The lifetime after long-term aging was predicted using Arrhenius equation.
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