| 학회 | 한국고분자학회 |
| 학술대회 | 2005년 봄 (04/14 ~ 04/15, 전경련회관) |
| 권호 | 30권 1호, p.529 |
| 발표분야 | 고분자 구조 및 물성 |
| 제목 | Studies on glycolysis degradation and crack generation mechanism of glass fiber reinforced nylon 6,6 |
| 초록 | Nylon 6,6 is a crystalline polymer with good mechanical and thermal properties and chemical stability. It is an important material used in tire cords and various types of automobile parts such as radiator end tank, intake manifold, engine cover, and timing belt cover1,2. Degradation of nylon 6,6 directly deteriorates its mechanical properties and hence, the chemical and physical mechanisms of degradation have been studied extensively for decades3,4. The objective of this work is to study the degradation mechanism of glass fiber reinforced nylon 6,6 (GFNY 6,6) in which nylon 6,6 component is (a) chemically degraded by ethylene glycol (used as a cooling liquid in automobiles) and (b) physically degraded by calcium chloride (used for melting ice on road during winter). Nylon 6,6 was treated with ethylene glycol in the mol ratio 1:2 at 275oC in an autoclave under high pressure. The glycolyzed samples were collected at various intervals of time and characterized using FT-IR, DSC, and GC-MS. From FT-IR spectra shown in Fig.1(a), the increase of ester band at 1733 cm-1 with reduction of amide band at 1632 cm-1 is observed as the glycolysis reaction time is increased. The increase in ester:amide absorbance ratio with increasing glycolysis reaction time is shown quantitatively in Fig. 1(b). GC-MS data reveal the presence of unreacted nylon 6,6 and also the presence of compounds having β-hydroxyethyl ester group, bis(β-hydroxyethyl)hexanoate and δ-valerolactone. Treatment of 15wt% CaCl2 aqueous solution with GFNY 6,6 over a period of time is expected to deteriorate its mechanical properties from being ductile to brittle. The shift in i.r. amide-I band to lower frequency as shown in Fig. 1(c) indicates that carbonyl oxygen-Ca+2 bond is formed and thereby, disrupting inter-chain hydrogen bonding3. Shift in i.r. amide–II band to higher frequency is due to complexation of hydrogen of N-H with Cl- and decrease of peak intensity of free amide-II band is associated with decrease of concentration of free amide-II bond. Also, the DSC data reveal a small decrease in the Tm and Tcm during heating and cooling respectively. The effect of different combinations of EG/CaCl2/H2O/MeOH mixture at different temperatures on the mechanical properties of GFRN 6,6 are also reported in our study. Figure 1. (a) FT-IR spectra for glycolyzed nylon 6,6 in the range 2000-600 cm-1, (b) changes in A1733/A1632 (ester/amide) as a function of glycolysis time and (c) ATR spectra for nylon 6,6 samples treated with 15 wt% CaCl2 aqueous solution. References: 1. M.I. Kohan, Nylon plastics handbook. New York: Hanser/Gardner, 1995. 2. P.L. Lann, T.S. Derevjanik, J.W. Snyder, W.C. Ward Jr., Thermochimica Acta, 357, 225 (2000). 3. P. Dunn and G.F. Sansom, J. Appl. Polym. Sci., 3, 1657 (1969). 4. B. Hommez and E.J. Goethals, JMSPAC, 35, 1489 (1998). Acknowledgement: One of the authors(KJK) greatly appreciates financial support from Hyundai Motor Company. |
| 저자 | D. Manjula Dhevi1, 이종순1, 조영달2, 최은경2, 김갑진1 |
| 소속 | 1경희대, 2한국생산기술천안(연) |
| 키워드 | Glycolysis; degradation; crack generation mechanism; nylon 66 |
