ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
By use of butyllithium as initiator and by incremental addition of monomers, block polymers of styrene, butadiene, and lactone can be prepared. Polymerization of ∊-caprolactone involves the displacement by base on the carbonyl carbon with the formation of an alkoxide endgroup. To polymerize lactone with poly(butadienyllithium), it is best to convert the carbon-lithium chain ends to alkoxide ends first. Styrene-butadiene-lactone terpolymers of high butadiene contents are thermoplastic rubbers. They have raw tensile strength equal to S-B-S triblock copolymer. Caprolactone-containing samples have unusually good ozone resistance; those prepared with the β-lactone of 2,2,4-trimethyl-3-hydroxy-3-pentenoic acid have much improved hot tensile strength. Terpolymers of low butadiene content are clear thermoplastic resins. Polymer of 20-20-60 (styrene-butadiene-caprolactone) polymer has raw properties similar to those of balata. It has high tensile, high tear strength, and similar hardness at room temperature, but higher softening point. Polymer alloy formed by mixing styrene-acrylonitrile copolymer and styrene butadiene capro lactone terpolymer has high tensile strength and excellent Izod impact. It compares favorably with ABS resin made by latex graft polymerization.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1978.070220420
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