New bio-based copolyesters poly(trimethylene 2,5-thiophenedicarboxylate-co-trimethylene terephthalate): Synthesis, crystallization behavior, thermal and mechanical properties

Polymer ◽  
2019 ◽  
Vol 173 ◽  
pp. 27-33 ◽  
Author(s):  
Guoqiang Wang ◽  
Min Jiang ◽  
Qiang Zhang ◽  
Rui Wang ◽  
Quanduo Liang ◽  
...  
Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1725
Author(s):  
Purba Purnama ◽  
Muhammad Samsuri ◽  
Ihsan Iswaldi

As one of the most attractive biopolymers nowadays in terms of their sustainability, degradability, and material tune-ability, the improvement of polylactide (PLA) homopolymer properties by studying the utilization of stereocomplex polylactide (s-PLA) effectively and efficiently is needed. In this sense, we have studied the utilization of s-PLA compared to poly D-lactide (PDLA) homopolymers as a nucleating agent for PLA homopolymers. The mechanical and thermal properties and crystallization behavior of PLA homopolymers in the presence of nucleating agents have been evaluated using a universal testing machine, differential scanning calorimeter, and X-ray diffractometer instruments, respectively. PDLA and s-PLA materials can be used to increase the thermal and mechanical properties of poly L-lactide (PLLA) homopolymers. The s-PLA materials increased the mechanical properties by increasing crystallinity of the PLLA homopolymers. PLLA/s-PLA enhanced mechanical properties to a certain level (5% s-PLA content), then decreased them due to higher s-PLA materials affecting the brittleness of the blends. PDLA homopolymers increased mechanical properties by forming stereocomplex PLA with PLLA homopolymers. Non-isothermal and isothermal evaluation showed that s-PLA materials were more effective at enhancing PLLA homopolymer properties through nucleating agent mechanism.


Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 164 ◽  
Author(s):  
Chien-Lin Huang ◽  
Hsuan-Hua Wu ◽  
Yung-Ching Jeng ◽  
Wei-Zhi Liang

In this study the effects of increased graphene nanosheet (GNS) concentration on variations in the structure and properties of electrospun GNS-filled poly(trimethylene terephthalate) (PTT/GNS) composite fiber, such as its morphologies, crystallization behavior, mechanical properties, and electrical conductivity, were investigated. The effects of GNS addition on solution rheology and conductivity were also investigated. GNSs were embedded in the fibers and formed protrusions. The PTT cold crystallization rate of PTT/GNS composite fibers increased with the gradual addition of GNSs. A PTT mesomorphic phase was formed during electrospinning, and GNSs could induce the PTT mesomorphic phase significantly during PTT/GNS composite fiber electrospinning. The PTT/GNS composite fiber mats (CFMs) became ductile with the addition of GNSs. The elastic recoveries of the PTT/GNS CFMs with 170 °C annealing were better than those of the as-spun PTT/GNS CFMs. Percolation scaling laws were applied to the magnitude of conductivity to reveal the percolation network of electrospun PTT/GNS CFMs. The electrical conductivity mechanism of the PTT/GNS CFMs differed from that of the PTT/GNS composite films. Results showed that the porous structure of the PTT CFMs influenced the performance of the mats in terms of electrical conductivity.


Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1160 ◽  
Author(s):  
Chin-Wen Chen ◽  
Te-Sheng Hsu ◽  
Kuan-Wei Huang ◽  
Syang-Peng Rwei

Unsaturated poly (butylene adipate-co-butylene itaconate) (PBABI) copolyesters were synthesized through melt polymerization composed of 1,4-butanediol (BDO), adipic acid (AA), itaconic acid (IA) and 1,2,4,5-benzenetetracarboxylic acid (BTCA) as a cross-linking modifier. The melting point, crystallization and glass transition temperature of the PBABI copolyesters were detected around 29.8–49 °C, 7.2–29 °C and −51.1 and −58.1 °C, respectively. Young’s modulus can be modified via partial cross-linking by BTCA in the presence of IA, ranging between 32.19–168.45 MPa. Non-isothermal crystallization kinetics were carried out to explore the crystallization behavior, revealing the highest crystallization rate was placed in the BA/BI = 90/10 at a given molecular weight. Furthermore, the thermal, mechanical properties, and crystallization rate of PBABI copolyesters can be tuned through the adjustment of BTCA and IA concentrations.


Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2257 ◽  
Author(s):  
Aleksandra Grząbka-Zasadzińska ◽  
Łukasz Klapiszewski ◽  
Sławomir Borysiak ◽  
Teofil Jesionowski

In this paper, silica–lignin hybrid materials were used as fillers for a polylactide (PLA) matrix. In order to simulate biodegradation, PLA/hybrid filler composite films were kept in soil of neutral pH for six months. Differential scanning calorimetry (DSC) allowed analysis of nonisothermal crystallization behavior of composites, thermal analysis provided information about their thermal stability, and scanning electron microscopy (SEM) was applied to define morphology of films. The influence of biodegradation was also investigated in terms of changes in mechanical properties and color of samples. It was found that application of silica–lignin hybrids as fillers for PLA matrix may be interesting not only in terms of increasing thermal stability, but also controlled biodegradation. To the best knowledge of the authors, this is the first publication regarding biodegradation of PLA composites loaded with silica–lignin hybrid fillers.


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