Anionic polymerization of 2-pyrrolidone and ε-caprolactam via CO₂/KOH catalysis was attempted in order to find reaction condition and physical properties of polymers.
In case of polymerization of 2-pyrrolidone, the yield of conversion was increased when the concentration of potassium hydroxide was reached above 8 mole percent. The optimum of CO₂/ KOH mole ratio was 0.45. It was also found that the polymerization was taking place at moderate temperature which was around 50℃.
With regard to polymerization of ε-caprolactam, the yield of conversion was relatively low at low temperature and higher yield of conversion was obtained at higher temperature between 150℃ to 180℃ with regardless of CO₂/KOH mole ratio.
The inherent viscosity of nylon 4 and nylon 6 which was made via CO₂/KOH catalysis was measured. The observed inherent viscosity was between 2.0 to 5.0.
Copolymerization of 2-pyrrolidone and ε-caprolactam was also attempted at 65℃ to 80℃.
Pysical properties of nylon 4, nylon 8 and copolymer synthesized via CO₂/KOH catalysis was investigated and compared with nylon 6 made by hydrolytic polymerization.
According to D.T.A measurement, the melting point of nylon 4 and copolymer which made via CO₂/KOH catalysis was 262℃ and 182℃, which indicating that the melting point of copolymer was lowered than that of pure nylon 6.
CO₂/KOH catalysis 에 의해 2-pyrrolidone 과 ε-caprolactam 의 음온 중합을 시도 하였으며 이 polymer 의 물리적 성질을 조사하였다.
2-pyrrolidone 중합의 경우에는, KOH 의 농도가 8 mole% 이상 이고 CO₂/KOH mole ratio 가 0.45 일때 percent conversion 이 가장 높았으며 50℃가 최적의 온도임을 알았다.
ε-caprolactam 의 중합에 있어서는, 낮은 온도에서는 percent conversion 이 낮았고, 150℃ - 180℃ 의 온도에서는 CO₂/KOH mole ratio에 관계없이 높은 percent conversion 을 얻었다.
CO₂/KOH catalysis 에 의해 합성한 nylon 4 와 nylon 6 의 고유점도는 대략 2.0 - 5.0 dl/gr 의 높은 값이었다. 65℃ - 80℃ 의 온도범위에서 2-pyrrolidone 과 ε-caprolactam 의 공중합도 시도하였다.
CO₂/KOH catalysis 에 의한 nylon 4 와 nylon 6, 그리고 공중합체의 물리적인 성질을 조사하여 hydrolytic polymerization 에 의한 nylon 6와 비교하였다.
D.T.A.측정 결과 CO₂/KOH catalysis 에 의해 합성한 nylon 4 와 공중합체의 융점은 각각 262℃, 182℃ 이었으며 공중합체의 융점은 nylon 6 의 융점 (215℃) 보다 낮음을 알 수 있었다.