The Effect of Mixed Chain Extender on the Hydrogen Bonding, Thermal and Mechanical Properties of TPUs

Chain extender plays a significant role in enhancing the final mechanical properties of thermoplastic polyurethane (TPUs) derived from polytetra methylene etherglycol (PTMG) and 4,4-diphenylmethane diisocyanate (MDI). In this research we focused on the effect that mixed chain extender of ethylene glycol (EG) and 1,4-butanediol (BDO) used has on the phase behavior and morphology of high hard block content TPUs. DSC, FTIR, and mechanical testing were mainly used to characterize the morphology and properties of the TPUs materials. Through this work we were able to show that mixed ratio of different chain extenders had dramatic effects on the properties of the TPUs. After mixing EG and BDO, the degree of hydrogen bonding, melting temperature, tensile strength, tear strength, and hardness of TPUs are all reduced, the glass transition temperature is increased. when the mixing ratio is 1: 1 , the elongation at break is increased to 672% . However, when the mixing ratio is n (EG): n (BDO) = 1: 2, the tensile strength is increased to 29.2 MPa, and the elongation at break is reduced to 353%.

Flexible Poly(imide) Siloxane Block Copolymers to Use at Biomedical Products

The novel research on organic polymer chemistry and physical organic chemistry involve poly(imide) siloxane on advanced and emerging technologies in radiation therapy. The poly(imide siloxane) block copolymers were synthesized at different production conditions for the use of biodegradable and biocompatible materials to use at biomedical products. These block copolymers were produced by using 4,4'-oxydianiline (ODA) and 3,3,4,4-Benzophenone-tetracarboxylic dianhydride (BTDA) to form polyimide hard block. APPS and BTDA formed the polysiloxane soft block. The polysiloxane soft blocks were increased by increasing the polyimide hard blocks. Copolymers are synthesized by adjusting the soft and hard segments. Copolymers can be obtained by holding constant hard block segments and by adjusting soft block segments. Hence, flexible poly(imide siloxane) block copolymers were derived. The samples were derived in a flexible rubber form. The prepared copolymers possess the properties of elastomers. Due to these properties, these materials have potential usage in microelectronics devices and medical devices. Poly(imide) siloxane, which can be produced with the desired form and conformed at different configurations, is important in such areas. In this research, the studies on poly(imide) siloxane have supported innovative and comprehensive radiation technology in polymer industries, experimental approaches for the innovative biomedical products. The samples were characterized as flexible rubber form and this property was detected and the creep test of poly (imide) siloxane was performed by Dynamic Mechanical Analyser (DMA).

Fully biobased thermoplastic elastomers: synthesis and characterization of poly(l-lactide)-b-polymyrcene-b-poly(l-lactide) triblock copolymers

Fully biobased thermoplastic elastomers poly(l-lactide)-b-polymyrcene-b-poly(l-lactide) triblock copolymers with PLLA as hard block and polymyrcene as soft block were synthesized and evaluated.

Control of hard block segments of methacrylate-based triblock copolymers for enhanced electromechanical performance

A series of well-defined hard–soft–hard triblock copolymers with various hard block segments were synthesized by Ru-based atom transfer radical polymerization (ATRP) (MWD < 1.26) in order to examine their electromechanical properties under electric fields.