Nylon 6–polyisobutylene sequential copolymers. II. Synthesis, characterization, and morphology of di‐, tri‐, and radial block copolymers

Abstract

Nylon 6–PIB diblock, triblock, and tristar radial block copolymers have been synthesized from telechelic hydroxyl‐terminated polyisobutylene, PIB(OH)n (n = 1,2,3), by conversion of this prepolymer with hexamethylene diisocyanate (HMDI), toluene diisocyanate (TDI), N‐chlorocarbonyl diisocyanate (NCCI), and oxalyl chloride (OxCl) and using the resulting materials as macroactivators for anionic caprolactam polymerization. Prepolymers with molecular weights from 6000 to 38,000 have been employed. Derivatization with NCCI and subsequent anionic caprolactam polymerization gave highest yields and blocking efficiencies. The block copolymers have been characterized by molecular weight and composition. In addition to the expected Tg and Tm characteristics of long PIB and nylon 6 segments, DSC studies showed an intermediate glass transition at ca. −20°C. Transmission electron microscopy of di‐, tri‐, and radial blocks show increasing segregation and orientation of rubbery/crystalline domains. Tensile strengths and elongations of the block copolymers range from 16.5 to 41 MPa and 15 to 30%, respectively, and stress‐strain diagrams show the effect of block architecture on these properties.

Novel Thermoplastic Elastomers: Polyisobutylene-block-polyamide Multiblocks

“…DSC: (DSC 2910 DuPont Instruments) sample weight, [5][6][7][8][9][10][11][12] mg; heating rate, 10 °C/min. All the DSC data reflect the second heating cycle.…”

Synthesis of Polyamide 6-block-Vinyl Polymers Using New Polyamide 6 Radical Initiators

“…1 However, there have been few studies on synthesis and characterization of block copolymers of P A6 with vinyl polymers except poly(styrene) (St) 2 -7 and rubbers such as poly-(butadiene-acrylonitrile), 8 -11 poly(St-butadiene), 12 • 13 poly(butadiene) 6 • 14 -16 and poly(isobutylene). 17 Melt polymerizations are often applied to the synthesis of block copolymers with PA6. 1 One problem is required thermal stability of vinyl polymer components.…”

Synthesis and Thermal Properties of Polyamide 6-block-Poly(cyclohexylmaleimide)

“…1 However, major vinyl polymers copolymerized with PA6 are poly(styrene) 2 -7 and rubbers such as poly(butadiene-acrylonitrile ), 8 -11 poly( styrenebutadiene), 12 • 13 poly(butadiene ) 6 · 14 -16 and poly(isobutylene). 17 There have been few studies on the synthesis and characterization of block copolymers of PA6 with vinyl polymers, except poly(styrene) and rubbers.…”