Jianjun Bao

N,N′-Bis(benzoyl) adipic acid dihydrazide and talc: nucleating agents for poly(l-lactic acid)

Abstract In this paper, high-heat-resistant polymeric composite products were prepared via the traditional melt blending process by incorporating N,N′-bis(benzoyl) adipic acid dihydrazide (BAAD) into poly(l-lactic acid) (PLLA), which acted as an organic nucleating agent. The heat distortion temperature (HDT) of the PLLA/BAAD composite samples was measured by an HDT apparatus, and a high value of 96.2°C was achieved at a BAAD loading fraction of 0.5 wt.%, whereas, at the same processing conditions, the HDT of PLLA/talc specimens reached a similar value at a talc content of 20 wt.%, which was much higher than the BAAD content. Differential scanning calorimetry and X-ray diffraction analyses were applied to determine the melting and crystallization behavior of the PLLA/BAAD blends. Polarized optical microscopy was used to observe the crystalline morphologies. Thermogravimetric analysis was employed to study the effect of BAAD on the thermal stability of PLLA. Measurement of the mechanical property confirmed that the addition of BAAD was beneficial to the enhancement of the mechanical properties of the resulting blends. However, the tensile strength of the PLLA/talc composites decreased with increasing weight fraction of talc.

Photoelectric and flexible poly(styrene-b-ethylene/butylene-b-styrene)-zinc porphyrin–graphene hybrid composite: synthesis, performance, and mechanism

Stretchable and flexible photoelectric materials are highly desirable for the development of artificial intelligence products. However, it remains a challenge to fabricate a stable, processable, and cost-efficient material with both high photoelectric sensitivity and remarkable deformability. Herein, a new kind of photoelectric sensitive, highly stretchable and environmentally adaptive materials was developed through in situ synthesis and π–π conjugation design. Specifically, a photoelectric elastomer zinc porphyrin SEBS(Zn-PorSEBS) was synthesized by introducing porphyrin to SEBS chain via a one-pot method. Then, graphene/zinc porphyrin SEBS (G/Zn-PorSEBS) composites were obtained by combing the elastomer with graphene sheets through solution blending. Notably, the resultant flexible composites were capable of capturing light changes with illumination on or off, and the maximum photocurrent density reached 0.13 μA cm−2. Moreover, the photoelectric composites exhibited a dramatic elongation (more than 1000%) and an excellent tensile strength about 20 MPa. This proposed strategy represents a general approach to manufacture photoelectric and flexible materials.