Ecoladrillos

Journal of Macromolecular Science R , Part B: Physics, 50:1491–1499, 2011
Copyright © Taylor & Francis Group, LLC
ISSN: 0022-2348 print / 1525-609X online
DOI: 10.1080/00222348.2010.518887

Study on Vulcanization and Thermal
Decomposition Behaviors of Methyl Vinyl Silicone
Rubber/Polyurethane Rubber Blends
LU-MIAO GAN,1 HAI-YING NI,1 YUAN-JIAN ZHOU,2
AND JUN CHEN1
1

College ofPolymer Science and Engineering, State Key Laboratory of Polymer
Materials Engineering, Sichuan University, Chengdu, Sichuan, China
2
Chenguang Research Institute of Chemical Industry, China National
Blue Star Co., Chengdu, Sichuan, China
The vulcanizing properties and thermal decomposition of methyl vinyl silicone rubber/
polyurethane rubber blends were studied. The results of vulcanization showthat with
the addition of polyurethane rubber, the viscosity, cross-linking density, activation energy and vulcanization rate of the blends decreased while the scorch behavior was
not significantly changed. For the decomposition behavior, the maximum thermal decomposition rate of the blends was increased with increasing content of polyurethane
rubber; however, the thermal stability of the blendswas decreased. Analysis of the
thermal decomposition kinetics shows that the activation energy of the blends gradually
decreased.
Keywords blends, methyl vinyl silicone rubber, polyurethane rubber

Introduction
Silicone rubber shows excellent resistance to both high and low temperatures and weather
ageing owing to its linear polysiloxane chemical structure, a main chain formed by Si-O-Sibonds. A large number of side methyl groups shield the molecular chains of polysiloxane,
endowing the resin with quite low polarity and low surface energy.[1,2] Silicone rubber also
shows excellent electrical insulation, high stability to thermal oxidation and ozone, and great
chemical inertness; however, its mechanical properties are generally not so satisfying.[3–7]
Silicone rubber hasgained considerable commercialization in recent years, and is
widely used in aerospace, automotive, electronics, office equipment, construction, medical,
and food industries.[8–11] With the desire for continuous improvement of applications, the
demands on silicone rubber have become higher and higher, and the traditional silicon
rubber products can not meet all the current requirements of industry,especially due to
their mechanical properties, fire-retardance and antiaging resistance.[12,13] Thus, methyl
vinyl silicone rubber was created for solving some of the deficiencies.
Received 22 March 2010; accepted 18 July 2010.
Address correspondence to Jun Chen, College of Polymer Science and Engineering, State Key
Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu,610065, Sichuan, China.
E-mail: cschen@vip.163.com

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The formula of the methyl vinyl silicone rubber is (MeViSiO)m (SiMe2 O)n R, where
R is methyl or vinyl groups. The random introduction of a small amount of vinyl side
(vi) groups can improve the vulcanization activity, extrusion efficiency, resistance to heat
aging, mechanical strength, and compression setof the vulcanized rubber. So, methyl vinyl
silicone rubber has become one of the most widely used silicone rubbers.[14]
Polyurethane, an amino methyl ester or urea-based polymer, usually shows a strong
polarity and can easily form hydrogen bonds among the molecular chains, which endows
it with high mechanical strength and good resistance to abrasion, oil, and ozone.[15,16] It
was the firstpolymeric material used as damping materials, and has been studied widely in
academics and industry.
The combination of silicone rubber and polyurethane may gives the resulting materials
and the respective advantages of both polymers. Currently, most studies on the combination
of silicone rubber and polyurethane have focused on the copolymerization of polysiloxane
and polyurethane, which gave...