높은 용융강도가 요구되는 용도로 사용하기 위하여, 기능성 단량체인 glycidyl methacrylate(GMA)가 첨가된 poly(lactic acid)(PLA)를 전자선 조사로 개질하였다. GMA의 양과 전자선량을 조절하여 다양하게 개질된 PLA를 제조한 후 열적 특성, 용융 점탄성 성질 및 겔화도를 조사하였다. GMA를 첨가하지 않고 전자선 조사로만 개질한 PLA의 복합점도와 저장 탄성률은 원래의 PLA의 값보다 더 낮았고 조사량이 증가하면 더욱 낮아졌다. GMA을 0.1 phr 또는 0.3 phr로 첨가하여 개질한 PLA의 물성의 조사량에 따른 변화 경향은 GMA를 첨가하지 않고 개질한 PLA와 비슷하지만, 0.5 phr GMA를 함유하며 전자선 조사량 5 kGy로 개질된 PLA는 원래의 PLA보다 낮은 주파수 영역에서 3배나 큰 복합점도와 10배나 큰 저장탄성률을 보였다.

In order to fabricate a modified poly (lactic acid) (PLA) for applications requiring high melt strength, a PLA has been irradiated in the presence of functional monomer of glycidyl methacrylate (GMA). Samples were prepared with various contents of GMA and irradiation dosages, and were characterized by observing their thermal and melt viscoelastic properties and gel faction. The complex viscosity and storage modulus of the modified PLA without GMA were lower than those of the original PLA. Those of the modified PLA decreased with increasing dosage. In the case of the modified PLA containing 0.1 phr or 0.3 phr of GMA, their changing tendency with dosage was similar to the irradiated PLA without GMA. However, the 5 kGy irradiated PLA containing 0.5 phr of GMA showed the greatly enhanced complex viscosity and storage modulus, which were about 3 and 10 times higher than those of the original PLA at a frequency of 0.1 rad/s, respectively.

Poly (lactic acid) Electron Beam Irradiation Glycidyl Methacrylate Complex Viscosity Modified Cole-Cole Plot

Narayan R, in K. C. Khemmani and C. Scholz(Eds.), Rationale, Drivers, and Technology Examples: Biobased & Biodegradable Polymer Materials, ACS, Washington DC (2006)
Lee JR, Chun SW, Kang HJ, Polym.(Korea), 27(4), 285 (2003)
Carlson D, Dubois P, Nie L, Narayan R, Polym. Eng. Sci., 38(2), 311 (1998)
Hogt AH, Meijer J, Jelenic J, in S. Al-Malaik(Ed.), Modification of Polypropylene by Organic Peroxides: Reactive Modifiers for Polymers, 84-132 (1996)
Meister JJ, Polymer Modification: Principles, Techniques, and Applications, Marcell Dekker, INC, New York (2000)
Kim DJ, Kang HJ, Seo KH, J. Appl. Polym. Sci., 81(3), 637 (2001)
Kim DJ, Kim WS, Lee DH, Min KE, Park LS, Kang IK, Jeon IR, Seo KH, J. Appl. Polym. Sci., 81(5), 1115 (2001)
Sodergard A, Niemi M, Selin JF, Nasman JH, Ind. Eng. Chem. Res., 34(4), 1203 (1995)
Di Y, Iannace S, Maio ED, Nicolais L, Macromol. Mater. Eng., 290(11), 1083 (2005)
Sugimoto M, Tanaka T, Masubuchi Y, Takimoto J, Koyama K, J. Appl. Polym. Sci., 73(8), 1493 (1999)
Han DH, Jang JH, Kim HY, Kim BN, Shin BY, Polym. Eng. Sci., 46(4), 431 (2006)
Han DH, Shin SH, Petrov S, Radiat. Phys. Chem., 69(3), 239 (2004)
Darwis D, Nishimura K, Mitomo H, Yoshii F, J. Appl. Polym. Sci., 74(7), 1815 (1999)
Yoshii F, Darwis D, Mitimo H, Makuuchi K, Radiat. Phys. Chem., 57, 417 (2000)
Yoshii F, Suhartini M, Nagasawa N, Mitomo H, Kime T, Nuclear Instruments and Methods in Physics Research B, 208, 370 (2003)
Gupta MC, Deshmukh VG, Polymer, 24(7), 827 (1983)
Van Krevelen DW, Properties of Polymers, Elsevier Sci. Pub. Com. INC, New York (1990)
Jamshidi K, Hyon SH, Ikada Y, Polymer, 29(12), 2229 (1988)
Auras R, Harte B, Selke S, Macromol. Biosci., 4(9), 835 (2004)
Yilmazer U, Xanthos M, Bayram G, Tan V, J. Appl. Polym. Sci., 75(11), 1371 (2000)
Kim ES, Kim BC, Kim SH, J. Polym. Sci. B: Polym. Phys., 42(6), 939 (2004)
Yang HH, Han CD, Kim JK, Polymer, 35(7), 1503 (1994)
Harrell ER, Nakajima N, J. Polym. Sci., 29(3), 995 (1984)
Park JW, Im SS, Kim SH, Kim YH, Polym. Eng. Sci., 40(12), 2539 (2000)
Chae HG, Kim BC, Im SS, Han YK, Polym. Eng. Sci., 41(7), 1133 (2001)
Jiao C, Wang Z, Liang X, Hu Y, Polym. Test, 24, 71 (2005)
Cleland MR, Park LA, Cheng S, Nuclear Instrument and Methods in Physics Research, B208(7), 66 (2003)
Barroso VC, Maia JM, Polym. Eng. Sci., 45(7), 984 (2005)