On the Flammability of the Electron-Beam-Induced Grafting of ABS and SBS Copolymers,Studied by LOI/CONE/XPS

Abstract

Pre-irradiation of the ABS and SBS copolymers, grafting of monomers (MAA and AA) onto both copolymers (ABS/SBS-g-MAA/AA) and ion exchange of the resulted grafts with cations, such as, Na⁺, K⁺, Mg²⁺, Ca²⁺(ABS/SBS-g-MAA/AA-S(Na⁺, K⁺/Mg²⁺, Ca⁺⁺) were involved in grafting. A study has been made using the elevated temperature LOI and CONE in this paper focusing on appraisal of the halogen- and phosphorus-free approach imparting flame retardancy to ABS and SBS copolymers and confirmation of carbon accumulation, extent of cross-linking and onset of charring as functions of temperature by the XPS technique. LOI technique at elevated temperatures and cone calorimetry based on the oxygen consumption principle give parameters definitely associated with the grafting rate (Gr), such as TI,, pk-HRR, SEA, EHC, etc., for each step in grafting. Flammability tests show that the grafting induced by electron beam has led to a large increase in LOI [e.g., ABS-MAA-S(Ca²⁺), +16.5 units], TI [e.g., SBS-g-MAA-S(Mg²⁺), +42.8°C]; cone (25 kW.m^-2): TTI [e.g., ABS-MAA- S(Na⁺²), +28%] and dramatic decreases in pk-HRR [e.g., ABS-MAA-S(Na⁺²), -67%), pk-MLR [e.g., ABS-MAA-S(Ca⁺²), -73%], SEA_F [e.g., SBSMAA-S(Ca⁺²), -65%], etc. Most experimental data were studied and confirmed by XPS data.

Keywords

grafting ABS SBS copolymers LOI cone XPS

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References

Deacon, C. and Wilkie, C. A. , 1996. “Graft copolymerization of acrylic acid on to acrylonitrile-butadiene-styrene terpolymer and thermal analysis of the copolymers,” Eur. Polym. J., 32, 4, 451-455.

Dong, X. , Geuskens, G. and Wilkie, C. A. , 1995. “Graft copolymers of methacrylic acid and SBS and K-resin by the anthracene photosensitized formation of hydroperoxides,” Eur. Polym. J., 32, 4, 451-455.

Wilkie, C. A. , Dong, X. and Suzuki, M. 1995. “Surface modification of polymers to achieve flame retardancy,” in Nelson, G. , ed., Fire and Polymers, ACS Symp. Ser. 599, pp. 236-244.

Wilkie, C. A. , Suzuki, M. , Dong, X. , Deacon, C. , Chandrasili, J. A. and Xue, T. , 1996. “Grafting to achieve flame retardancy,” Polymer Degradation and Stability, 54, 117-124.

Grand, A. F. and Wilkie, C. A. , ed., 2000. Fire Retardancy of Polymeric Materials, Marcel Dekker, Inc., pp. 177.

Wang, J. , Zhang, S. , Xie, L. and Wen, C. , 1997. “Approaches to the flame retardancy of polymers I. Electron-beam pre-irradiation and grafting of acrylic monomers onto EVA copolymers,” Journal of Fire Sciences, 15, 1, January/February, 68-87.

Zhang, S. , Wang, J. , Xie, L. and Wen. C. , 1997. “On Electron-beam (EB) irradiation and grafting of acrylic monomers onto EVA copolymers,” Chinese Science Bulletin, 42, 18, September, 1549-1554.

Zhang, S. , Wang, J. , Ding, Y. , Wu, S. , Xie, L. and Wen, C. , 1999. “Electron-beam induced grafting onto EPDM,” Chinese Science Bulletin, 44,14, July, 1503-1507.

Zhang, S. , Wang, J. , Wen, C. and Xie, L. , 1999. Proceedings of 7th European Conference, Greenwich, UK, September.

10.

Wu, S., 1999. “New Approaches to Flame Retardancy of Copolymers (ABS/SBS): Grafting via Electron-Beam Technique,” Doctoral Thesis, Beijing Institute of Technology, Beijing, China.

11.

Babrauskas, V. , 1992. In Heat Release in Fire, V. Babrauskas and S.J. Grayson , eds., Elsevier Applied Science, Chap. 4, 61-91.

12.

Wang, J. and Li, B. , 1999. “An XPS investigation of thermal degradation and charring in combustion of PVC/Cu2O/MoO3—the synergy between Cu2O and MoO3 in PVC,” Polymer Degradation & Stability, 63, 279-285.

13.

ASTM Standard D2863-91 , 1992. Annual Book of ASTM Standards, Philadelphia, PA: American Society for Testing and Materials.

14.

Macaione, D. P. , Dowling, R. P. III and Bergquist, P. R. 1983. Summary Report, AMRC TR 83-53, Watertown, MA: Army Matl. & Mechanics Research Center.

15.

Redfern, J. P., Tech. Inf. Sheet No. 24, Surrey, England: Stanton Redcroft.

16.

Bates, S. C. and Solomon, P. R. 1993. “Elevated temperature oxygen index apparatus and measurements,” Journal of Fire Sciences, 11, May/June, 271-284.

17.

Han, S. , Qian, L. , Du, J. , Li, B. and Wang, J. , 1999, “The temperature dependence of LOIs of PVC/transition metals,” Chinese Science Bulletin, in press.

18.

Wu, S., 1999. “New approach to flame retardance of copolymers ABS and SBS by electron-beam grafting,” Doctoral Thesis, Beijing Institute of Technology, p. 14.

19.

Wang, J. , 1998. “Studies on thermal degradation and charring of polymers by XPS/TGA to reexamine the transition temperature TGRL of the graphite-like structure for polymers on heating,” in Fire Retardancy of Polymers, The Use of Intumescence, pp. 159-172, M. Le Bras, G. Camino, S. Bourbigot and R. Delobel , eds., The Royal Society of Chemistry, UK.

20.

Hao, J. , Wu, S. , Wilkie, C. A. , and Wang J. , 1999. “An XPS study of the radiation-induced effect on the thermal degradation and charring of butadiene and its copolymers,” Polymer Degradation and Stability, 66(1) 81-86.

21.

Hao, J. , Wilkie, C. A. and Wang, J. , 2000. “An XPS investigation of thermal degradation and charring of cross-linked polyisoprene and polychloroprene,” Polym. Degrad. Stab., 71, 305.

22.

Allinger, N. L. , Cava, M. P. , De Jongh, D. C. , Johnson, C. R. , Lebel, N. A. and Stevena, C. L. , 1971. Organic Chemistry, Worth Publishers, Inc., pp. 146-147.

23.

Arlie, J.-P. , 1990. Commodity Plastics, Technical and Electronic Characteristics, GULF Publishing Company, Houston, TX, p. 83.