압출성형을 통한 core/shell 구조를 갖는 폴리부틸렌테레프탈레이트(PBT)/Nylon6,12 미세모를 제조함에 있어 최적의 압출조건을 규명하기 위하여, 압출온도와 배합비를 다르게 하여 제조한 블렌드 미세모의 상용성을 SEM 모폴로지와 DSC 분석을 통해 확인하고 UTM을 통해 압출속도에 따른 기계적 물성의 변화를 측정하였다. SEM 모폴로지 분석결과 압출온도가 증가할수록 분산상인 Nylon6,12 비드의 크기가 감소하였으며, Nylon6,12의 함량이 증가할수록 PBT 매트릭스 내 Nylon6,12의 상분리 현상이 감소하였다. DSC 분석 결과도 같은 경향을 나타냈는데, 압출온도가 상승함에 따라 녹는점에 해당하는 피크들의 경계가 사라지고, Nylon6,12의 비율이 증가할수록 두 피크의 간격이 좁아지는 것을 확인할 수 있었다. 한편 PBT/Nylon6,12 블렌드 미세모의 인장강도와 연신율 및 굴곡강도와 굴곡탄성률 모두 압출온도_x000D_ 가 260 ℃ 일 때까지 증가하였으나 그 이상의 온도에서는 오히려 감소하였다. 260 ℃에서의 인장강도와 연신율, 굴곡강도, 굴곡탄성률은 각각 560 kgf/cm2와 220%, 807 kgf/cm2, 22,146 kgf/cm2였는데 이는 PBT와 Nylon6,12의 중간 값을 상회하는 수치로 두 물질이 압출성형에 의한 블렌드 효과가 있다는 것을 확인할 수 있었다. 이처럼 우수한 상용성을 보일 때의 블렌드 압출 조건들을 토대로 하여 core/shell 구조의 이중구조 미세모를 제조하였다.

Poly(butylene terephthalate) (PBT)/Nylon6,12 core/shell micro fiber were prepared by extrusion molding. To investigate their optimum extrusion conditions, compatibility of PBT/Nylon6,12 blend micro fiber in conformity to their weight ratio and manufacture temperature was explored with SEM morphology and DSC. The alterations in their mechanical properties by extrusion speed were compared and analyzed through a UTM. In comparison with SEM figures, the domain sizes of Nylon6,12 were gradually declined by increasing the extrusion temperature of blends. Furthermore, according to these SEM images, the phase separation between Nylon6,12 domain and PBT matrix became indistinct with increasing of weight percentage of Nylon6,12. In case of DSC, the boundaries of two peaks were almost disappeared when increasing the extrusion temperature and also intervals of each two melting peaks became narrow as increasing the Nylon6,12 ratio. The mechanical properties including tensile strength, elongation, flexural strength and flexural modulus were increased as the increase in the extrusion temperature until 260 ℃. However, the mechanical properties were actually deteriorated over 260 ℃. The tensile strength, elongation, flexural strength and flexural modulus at 260 ℃ were 560 kgf/cm2, 220%, 807 kgf/cm2 and 22,146 kgf/cm2, respectively. These values are more than intermediate values of mechanical properties of PBT and Nylon6,12. These results mean that there is compatibility between PBT and Nylon6,12. Based on the extrusion conditions that produced optimum compatibility of blend, as a result, our group obtained micro fibers with the core/shell structure.

PBT/Nylon6,12 Core/shell Blend Extrusion Compatibility Mechanical Properties

Mahfuz H, Hasan MM, Rangari VK, Jeelani S, Macromol. Mater. Eng., 292(4), 437 (2007)
Lyu MY, Choi DH, Kim YH, Nah C, Polym.(Korea), 34(3), 237 (2010)
Mallick S, Khatua BB, J. Appl. Polym. Sci., 121(1), 359 (2011)
Araujo EM, Hage E, Carvalho AJF, J. Mater. Sci., 39(4), 1173 (2004)
Hasan MM, Zhou Y, Mahfuz H, Jeelani S, Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process., 429(1-2), 181 (2006)
Penning JP, van Ruiten J, Brouwer R, Gabrielse W, Polymer, 44(19), 5869 (2003)
Lee YK, Kim JM, Kim WN, Korean Chem. Eng. Res., 49(4), 438 (2011)
Kim D, Kim SW, Korean J. Chem. Eng., 20(4), 776 (2003)
Jordhamo GR, Manson JA, Sperling LH, Polym. Eng. Sci., 26(8), 517 (1986)
Wu S, Polym. Eng.Sci., 27(5), 335 (1987)
Elmendorf JJ, van der Vegt AK, Polym. Eng. Sci., 26(19), 13332 (1986)
Willis JM, Favis BD, Lavallee C, J. Mater. Sci., 28(7), 1749 (1993)
Vainio T, Hu GH, Lambla M, Seppala JV, J. Appl. Polym. Sci., 61(5), 843 (1996)
Huang CC, Chang FC, Polymer, 38(9), 2135 (1997)
Huang CC, Chang FC, Polymer, 38(17), 4287 (1997)
Kang TK, Kim Y, Cho WJ, Ha CS, Polym. Eng. Sci., 36(20), 2525 (1996)
Kim SJ, Kim DK, Cho WJ, Ha CS, Polym. Eng. Sci., 43(6), 1298 (2003)
Scaffaro R, Botta L, La Manita FP, Gleria M, Bertani R, Samperi F, Scaltro G, Polym. Degrad. Stab., 91(10), 2265 (2006)
Tsi HY, Tsen WC, Shu YC, Chuang FS, Chen CC, Polym. Test., 28(8), 875 (2009)
Elmqvist C, Svanson SE, Eur. Polym. J., 12(8), 559 (1976)
Paci M, Liu M, Magagnini PL, La Manita FP, Valenza A, Thermochim.Acta., 137(1), 105 (1988)
Lee JG, Park SH, Kim SH, Polym.(Korea), 34(6), 579 (2010)
Kim BS, Sang YJ, Polym.(Korea), 20(2), 297 (1996)