Super‐ductile PBT alloy with excellent heat resistance

Abstract

A super-ductile PBT alloy with excellent heat resistance was successfully fabricated by reactive blending of poly(butylene terephthalate) (PBT) with poly(ethylene-coglycidyl methacrylate) together with linear low density polyethylene (LLDPE) and hydrogenated styrene-butadiene-styrene block copolymer (SEBS). It possesses a unique tensile stress-strain curve with no yielding point and large elongation at break, moreover, the alloy did not show serious deterioration of the mechanical properties by high temperature annealing at 1508C for 96 h. The structure-properties relationship is discussed on the basis of transmission electron microscopy, differential scanning calorimetry, dynamic mechanical analysis, and wide-angle X-ray diffraction analysis. The outstanding ductile nature seems to come from the negative pressure effect of LLDPE (or LLDPE/SEBS) particles that dilates the PBT ligament matrix to enhance the local segment motions.

Water‐disintegrative and biodegradable blends containing poly(L‐lactic acid) and poly(butylene adipate‐co‐terephthalate)

“…A similar T g depression at low temperature ranges is also reported in other polymeric systems composed of rubber‐toughened glassy polymers, for example, acrylonitrile‐butadiene‐styrene copolymer,46 styrene‐rich styrene‐butadiene diblock copolymers,47 and poly(butylene terephthalate) blended with poly(ethylene‐ co ‐glycidyl methacrylate) and linear low‐density polyethylene 48. Inoue and coworkers48 reported that the T g depression of the rubbery component results in significant enhancement of ductility.…”

Physical aging and thermal aging resistance of polycarbonate/poly(styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene) blends

“…It has been previously shown that poly(styrene‐ b ‐(ethylene‐ co ‐butylene)‐ b ‐styrene (SEBS) can toughen semicrystalline polymers, such as poly(lactic acid) (PLA) and poly(butylene terephthalate) (PBT) [1, 2]. However, both neat PLA and neat PBT become very brittle by high‐temperature annealing.…”

“…For these semicrystalline polymers, the embrittlement is probably caused by crystallization; for example, a decrease of the amount of amorphous material and an increase in crystal lamellar thickness, and the physical aging of amorphous region. For PBT, the effect of crystallization was negligibly small [2], and the embrittlement is mostly due to physical aging.…”

Toward superior applications of thermoplastic elastomer blends: double Tg increase and improved ductility

“…For the rubber phase an evident T g depression was observed in the P100H and P70H30X blends, where rubber is present in discrete domains. Many research studies have reported the depression of the rubber T g in systems consisting of microspherical inclusions of a rubber in a rigid plastic matrix . In such systems, the difference in the thermal contraction between the two phases would generate a negative pressure in the rubber phase, which results in an increase of the free volume and correspondingly a decrease of the T g of the rubber phase.…”