3기능성 모노머인 트리메틸로프로판트리아크릴레이트(TMPTA)와 트리아릴 시아네이트(TAC)이 가교제로 첨가된 호모폴리프로필렌(homo-polypropylene: HPP)과 랜덤 터폴리프로필렌(random ter-polypropylene: RTPP)의 전자빔 조사는 비교적 높은 가교도를 보였다. 여기서 TMPTA가 첨가된 HPP와 RTPP의 최대가교도는 5 kGy에서 각각 67%와 52%인 반면에, TAC가 첨가된 HPP의 가교도는 방사선량에 따라 연속적으로 증가하여서 240 kGy에서 65%에 도달하였다. 젤함량, 용융지수, 팽윤율, 평균분자량 분포와 같은 여러 실험 데이터로부터, TAC가 첨가된 HPP와 TMPTA가 첨가된 RTPP는 TMPTA가 첨가된 HPP보다 높은 조사선량에서 훨씬 높은 방사안정성이 있음을 밝혔다. 용융열 데이터로부터 방사가교는 조사된 폴리프로필렌에서 결정도 변화에 거의 영향을 주지 않으며 가교는 결정영역과 무정형영역의 경계면에서 주로 일어남을 보였다. 2 mmol%이상의 TMPTA가 첨가된 HPP는 과량의 모노머에 의한 자체의 호모중합 때문에 가교 되기가 어려웠다.

Electrons-irradiated homo-polypropylene(HPP) and random ter-polymer of propylene(RTPP), in which trifunctional monomers such as trimethylopropanetriacrylate(TMPTA) or triallylcyanuate(TAC) was added as crosslinking agent, showed comparably high degree of crosslinking: wherein the maximum degree of crosslinking was 67% and 52% around at 5 kGy for HPP and for RTPP, respectively, both added with TMPTA, whereas the degree of crosslinking in HPP with TAC continuously increased with radiation dosages, reaching to 65% at 240 kGy. From several experimental data such as, gel content, melt index, swelling ratio, and average molecular weight distribution, HPP with TAC and RTPP with TMPTA were found out to be much higher radiation-stable than HPP with TMPTA, especially at high dosages. The heat of fusion data could show that radiation crosslinking hardly gave an effect on changing of crystallinity in the irradiated polypropylene and could occur mainly at boundaries between crystalline and amorphous phases. It was found that HPP added with more than 2 mmol% of TMPTA were difficult to be highly crosslinked probably due to a homopolymerization by an excess of this monomer.

Polypropylene Radiation Crosslinking Electron Beam Trifunctional Monomer Radiation Degradation

Wang UP, J. Industrial. Irradiation. Technol., 1(1), 1 (1983)
Scheve BJ, Mayfied JW, Denicola AJ, U.S. Patent, 4,916,198 (1990)
Fouassier JP, Rabek JF, "Radiation Curing in Polymer Science and Technology," Elsevier Science Publishers Ltd., England, 1, 193 (1993)
Bradley R, "Radiation Technology Handbook," Marcel Dekker, Inc., New York, 299, 134 (1984)
Yoshii F, Sasaki F, Makuuchi K, Tamura N, J. Appl. Polym. Sci., 31, 1343 (1986) 
Zaharah AK, Yoshii F, Makuuchi K, Ishikaki I, Polymer, 30, 1425 (1989) 
Yoshii F, Meligi G, Sasaki T, Makuuchi K, Rabei AM, Nishimato S, Polym. Degrad. Stabil., 49, 315 (1995) 
Makuucji K, Hagiwara M, J. Appl. Polym. Sci., 29, 401 (1984)
Ynushu X, Yoshii F, Makuuchi K, J. Macromol. Sci. Schem., A32(10), 1803 (1995)
Clough R, "Radiation-resistant Polymer," in Encyclopedia of Polymer Science and Engineering, John wiley and Sons, 667 (1988)
Dole M, Polym. Plast. Technol. Eng., 13, 41 (1979)
Keller A, Ungar G, Radiat. Phys. Chem., 22, 155 (1983) 
O'Donnell JH, Whittaker AK, Pure Appl. Chem., A29(1), 1 (1992)
Dole M, Patel VM, Radiat. Phys. Chem., 9, 433 (1977) 
Mitsui H, Shimizu Y, J. Polym. Sci. A: Polym. Chem., 17, 2805 (1979)
Hadlos VN, Singer KA, J. Appl. Polym. Sci., 20, 3375 (1976) 
Basheer R, Dole M, J. Polym. Sci. B: Polym. Phys., 21, 949 (1983)
Sawasaki T, Nojiri A, Radiat. Phys. Chem., 31(4-6), 877 (1988)
Soebianto YS, Kusuhata I, Kotsumura Y, Ishigure K, Kubo J, Kudoh H, Seguchi T, Polym. Degrad. Stabil., 50, 203 (1995) 
Geuskens G, Nedelkos G, Makromol. Chem., 194, 3349 (1993) 
Horng PL, Klemchuck PP, Plast. Eng., 4, 35 (1984)
Yoshii F, Makuuchi K, Kikukawa S, Tanaka T, Saitoh J, Koyama K, J. Appl. Polym. Sci., 60, 617 (1966) 
Hegazy ESA, Zaharan AH, Radiat. Phys. Chem., 27, 323 (1986)
Yoshii F, Meligi G, Sasaki T, Polym. Degrad. Stabil., 49, 315 (1995)