JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Linda Yahia Cherif,Nacira Naar,Ahmed Mekki,Amina Ouadah,Rania Ahmed Hamada,Djalal Trache
Polylactic acid (PLA) is a biosourced thermoplastic polymer widely used in various fields such as biomedical, packaging, and prototyping. Enhancing PLA thermal and mechanical properties has been a research focus, by transforming it into a vitrimer, a new polymer class. This study demonstrated the effectiveness of a dual reactive extrusion process followed by vacuum compression molding to improve a thermoplastic's properties with vitrimer tendency, using PLA as the main component, diglycidyl ether bisphenol A (DGEBA) as an additive, and zinc acetate as a catalyst. Several characterizations were carried out to assess the thermal, morphological, and mechanical properties of the developed PLA mixtures. Moreover, a kinetic study using three iterative isoconversional integral models (iterative Kissinger–Akahira–Sunose (it-KAS), iterative Flynn–Wall–Ozawa (it-FWO), and Trache–Abdelaziz–Siwani) was employed to analyze the effects of the catalyst and DGEBA on the cross-linking reaction kinetics after the process employed in this work. Results demonstrated the presence of a cross-linked structure in addition to a promising polymer behavior characterized by enhancements in toughness, ductility, and cross-linking density by 290%, 127.5%, and 80.5%, respectively. Finally, the optimal composition exhibited almost 96% self-healing of its surface, demonstrating significant potential for advanced material applications.
研究领域:
材料科学
·
聚合物化学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2020
·
IF 6.551
Qi Tang,Kang Wang,Xiaoming Ren,Qunchao Zhang,Weiwei Lei,Tao Jiang,Dean Shi
Antibacterial polymer membranes have been widely used in many fields of our daily life. In this study, porous PA6 membrane with ZnO nanoparticles attaching on to the surface of inner pore walls is prepared. Firstly, SMA (styrene maleic anhydride copolymer) is used to graft onto the surface of ZnO nanoparticle in DMF (dimethylformamide). Then the pre-treated ZnO nanoparticles (ZnO-SMA) are added into SEBS (Styrene-ethylene-butylene-styrene copolymer)/PA6 (60/40 wt/wt) blends with co-continuous morphology. The effects of SMA molecular structure (molecular weight and maleic anhydride content) used for ZnO-SMA nanoparticles on their dispersion states in SEBS/PA6/ZnO-SMA nanocomposites are investigated. When SMA3 (MAH = 8 wt%, Mn = 250,000 g mol −1 ), which has relatively higher molecular weight and lower MAH content, is used as the pre-treating agent, ZnO-SMA3 nanoparticles tend to be dispersed at the phase interface in SEBS/PA6/ZnO-SMA nanocomposites. However, when SMA2 (MAH = 23 wt%, Mn = 110,000 g mol −1 ) with relatively lower molecular weight and higher MAH content is used, no ZnO-SMA2 nanoparticles locate at the interface but stay within PA6 phase. Porous PA6 membranes are obtained by selectively etching SEBS phase out with xylene. It can be found that porous PA6 membrane containing ZnO-SMA3 nanoparticles still exhibits much better antibacterial property (R = 3.76) toward S. aureus even at a very low ZnO content (0.5 wt%). This result should be ascribed to almost all the ZnO-SMA3 nanoparticles being exposed to the surface of inner pore walls of PA6 membrane. This work proposes an effective method to prepare porous polymer membrane with functional nanoparticles selectively located at the inner pore walls.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
PubMed
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2021
·Vol. 32
·期 6
·2352-2366
·
IF 3.665
Feng-Jiao Li,Xi-Tong Yu,Zan Huang,Ding-Fu Liu
Grafting of polylactide (PLA) onto the cellulose nanofiber (CNF) (CNF-g-PLA) was prepared by in situ reactive extrusion using dicumyl peroxide (DCP) as a free radical initiator to improve the interfacial adhesion between CNFs and PLA. The effect of DCP content on the dynamic rheological properties, crystallization behavior, mechanical properties, and micromorphology of PLA/CNF (95/5) bionanocomposite was systematically investigated. FTIR spectra confirmed that PLA chains were successfully grafted onto the CNF surface by forming C C bonds. The presence of such C C crosslinks improved stress transfer at the CNF–PLA interface; SEM and TEM observations and adhesion factor calculated from DMA data confirmed that the synthesized graft copolymers improved the interfacial interaction between CNFs and PLA matrix, thus enhancing the mechanical properties of CNF-g-PLA nanocomposites. Compared with PLA/CNF (95/5) bionanocomposite, the maximum tensile modulus, tensile strength, elongation at break, and V-notched Izod impact strength of CNF-g-PLA nanocomposites were increased by 31.8%, 20.0%, 12.0%, and 27.9%, respectively. WAXD and DSC analyses indicated that the crystallinity degree of the grafted CNF-g-PLA was higher than that of PLA/CNF (95/5) bionanocomposite, and first increased and then decreased with increasing DCP content. The polarized optical micrographs confirmed that DCP-initiated grafting significantly increased the nucleation density but decreased the spherulite size of PLA. The melt strength of CNF-g-PLA nanocomposites was improved due to stronger intermolecular interaction by grafting. This one-step in situ reactive extrusion technology provides an efficient and economical way to enhance the properties of PLA/CNF bionanocomposites.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
STARCH-STARKE
·
2019
·
IF 1.795
Canxin Cai,Yaoqi Tian,Zhiwei Yu,Chunrui Sun,Zhengyu Jin
The in vitro digestibility of chemically modified rice starch by one-step reactive extrusion (REX) via esterification, acetylation, hydroxypropylation, and cross-linking or dual-modification (hydroxypropylation-cross-linking and acetylation-cross-linking) is investigated. After REX processing, pasting viscosity is decreased, while the viscosity of esterification samples is lower than that of cross-linking samples. Molecular structure analysis suggests that the degradation of starch molecules is retarded by esterification whereas enhanced by cross-linking. Dual modification (hydroxypropylation and phosphorylation, hydroxypropylation-cross-linking (HP-CL) sample) involving hydroxypropylation and phosphorylation (HP-CL sample) is more conducive to preventing enzyme hydrolysis than the other modifications. HP-CL sample achieves the lowest predicted glycemic index (pGI) value (88.1) and the highest RS content (15.3%). Thus, the one-step REX is a useful method for reducing rice starch digestibility or pGI value.
研究领域:
食品科学
·
生物化学
✓ 已验证
DOI
高影响因子
MRS Communications
·
2020
·Vol. 10
·期 3
·487-491
·
IF 1.997
Zhenghui Li,Lu Chen,Peijie Yu,Lingli Zhang,Hongyu Hu
To overcome the steric effect of norbornene (NB), first-generation Grubbs’ catalyst (GC1) was used as the catalyst to graft NB onto the polypropylene (PP) chain by reactive extrusion. Instead of harsh reaction conditions, such as anhydrous, which was the general method to synthesize NB polymers, this convenient method would be easier to industrialize. The mechanism of grafting was studied by using Fourier Transform InfraRed spectra and differential scanning calorimetry. It was found that GC1 could initiate the ring-opening metathesis polymerization of NB to obtain short NB chain-grafted PP-g-NB. The rheological behavior showed that the grafted NB short chains on PP-g-NB increase the shear thinning of the polymers and decrease the system viscosity.
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
Materials
·
2019
·Vol. 12
·期 9
·1565
·
IF 2.972
Yang Qin,Wentao Wang,Hui Zhang,Yangyong Dai,Hanxue Hou,Haizhou Dong
Hydroxypropyl amylomaize starch (HPAS) films were prepared by hot press. The effects of initial pH of HPAS on the mechanical properties, molecular interaction, structure, and cross-linking degree of the resultant films were investigated. A weak acidic condition was suitable for cross-linking of citric acid and HPAS by reactive extrusion. The film of HPAS with an initial pH of 5.66 had the maximum tensile strength of 7.20 MPa and elongation-at-break of 94.53%, and the weight average molecular weight of HPAS increased to 4.17 × 105g/mol. An appropriate initial pH facilitated the formation of diester bonds between HPAS and citric acid during extrusion, but too low initial pH levels resulted in hydrolysis of starch molecules and reduced the mechanical properties.Keywords:hydroxypropyl amylomaize starch;citric acid;cross-linking;reactive extrusion;biodegradable plastic film
研究领域:
材料科学
·
食品科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COMPOSITES PART B-ENGINEERING
·
2021
·
IF 9.078
Yufei Liu,Shan Liu,Zhentao Liu,Yang Lei,Siyuan Jiang,Kai Zhang,Wei Yan,Jun Qin,Min He,Shuhao Qin,Jie Yu
Biodegradable polymers , including polybutylene adipate-co-terephthalate (PBAT), can replace traditional plastics to effectively target microplastic pollution; however, their high cost limits their application. In this study, vinyltrimethoxysilane (VTMS)-grafted lignin (VL) was prepared and incorporated into PBAT to reduce its cost and improve its mechanical properties while maintaining its biodegradability. Results show that the tensile strength , Young's modulus , and biodegradation efficiency of a PBAT/VL-30% composite increased by 200%, 151%, and 96%, respectively, compared with neat PBAT. VTMS grafting onto lignin thus improves the dispersion of lignin in PBAT; a network structure of PBAT and VL is formed via reactive extrusion . This work provides a theoretical basis for the design and development of low-cost, highly biodegradable PBAT composites.
研究领域:
材料科学
·
环境科学
·
高分子化学
✓ 已验证
DOI
高影响因子
MACROMOLECULES
·
2021
·
IF 5.985
Jianfan Qiu,Songqi Ma,Sheng Wang,Zhaobin Tang,Qiong Li,Anping Tian,Xiwei Xu,Binbo Wang,Na Lu,Jin Zhu
Vitrimers are expected to combine features of thermosets and thermoplastics but their continuous reprocessing is still a challenge; poly(ethylene terephthalate) (PET) has been widely used in our daily life, while its cross-linking upcycle contradicts with processability. Herein, we combined polyol with a tertiary amine structure and diepoxy to transform PET to continuously reprocessable vitrimers through an industrial twin-screw extruder. The cross-linking of PET was determined by swelling and rheology experiments, and the vitrimer feature was characterized by stress relaxation and oscillatory frequency sweep experiments. Creep resistance and mechanical properties of PET vitrimers were improved greatly relative to neat PET. Meanwhile, PET vitrimers exhibited excellent reprocessability via compression, extrusion, and injection molding suitable for industrial production. According to this work, any thermoplastics containing ester bonds should be able to be upgraded to vitrimers for additional advantages such as creep resistance, dimensional stability, insolubility, etc., without sacrificing the original processability.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2014
·Vol. 25
·期 6
·605-612
·
IF 1.964
Liyan Ma,Bin Yu,Xiaodong Qian,Wei Yang,Haifeng Pan,Yongqian Shi,Lei Song,Yuan Hu
A reactive extrusion process was developed to fabricate polymer/graphene nanocomposites with good dispersion of graphene sheets in the polymer matrix. The functionalized graphene nanosheet (f-GNS) activated by diphenylmethane diisocyanate was incorporated in thermoplastic polyester elastomer (TPEE) by reactive extrusion process to produce the TPEE/f-GNS masterbatch. And then, the TPEE/f-GNS nanocomposites in different ratios were prepared by masterbatch-based melt blending. The structure and morphology of functionalized graphene were characterized by Fourier transform infrared, X-ray photoelectron spectroscopy, X-ray diffraction and transmission electron microscopy (TEM). The incorporation of f-GNS significantly improved the mechanical, thermal and crystallization properties of TPEE. With the incorporation of only 0.1 wt% f-GNS, the tensile strength and elongation at break of nanocomposites were increased by 47.6% and 30.8%, respectively, compared with those of pristine TPEE. Moreover, the degradation temperature for 10 wt% mass loss, storage modulus at −70°C and crystallization peak temperature ( T cp ) of TPEE nanocomposites were consistently improved by 17°C, 7.5% and 36°C. The remarkable reinforcements in mechanical and thermal properties were attributed to the homogeneous dispersion and strong interfacial adhesion of f-GNS in the TPEE matrix. The functionalization of graphene was beneficial to the improvement of mechanical properties because of the relatively well dispersion of graphene sheets in TPEE matrix, as suggested in the TEM images. This simple and effective approach consisting of chemical functionalization of graphene, reactive extrusion and masterbatch-based melt blending process is believed to offer possibilities for broadening the graphene applications in the field of polymer processing. Copyright © 2014 John Wiley & Sons, Ltd.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Nano Materials Science
·
2021
·
IF 0
Tianqi Liang,Jie Liu,Zhaoyang Wei,Dean Shi
In this study, CuO nanoparticles are pre-modified with styrene-maleic anhydride copolymers (SMAs) of different molecular weights and MAH contents. Then the pre-modified CuO nanoparticles (CuO-SMAs) are added to the PA6/SEBS (Styrene Ethylene Butylene Styrene copolymer) (40/60 wt/wt) polymer blends with a co-continuous morphology. When SMA3 (MAH = 8 wt%, M n = 250000 g/mol) is used to modify CuO nanoparticles, and the grafting degree of SMA3 on the surface of CuO reaches 2.74 wt%, 90.71% of the added mCuO-SMA3 nanoparticles can be located at the interface of PA6 and SEBS. A porous PA6 membrane with CuO nanoparticles located at the pore walls can be obtained after the SEBS phase is etched with xylene. The catalytic reaction velocity constant (k) for the reduction of p-nitrophenol in NaBH 4 solutions with the PA6/mCuO-SMA3 porous membrane can reach 1.0040 min -1 . This work provides a feasible and straightforward method for the preparation of porous polymer membranes with functional nanoparticles located at the wall of the pores.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
JOURNAL OF APPLIED POLYMER SCIENCE
·
2021
·Vol. 138
·期 39
·51010
·
IF 3.125
Yue Yin,Jian Yang,Linghui Meng
Poly(butylene succinate) (PBS) refers to a high-performance biodegradable polymer employed to substitute petroleum polymers that cause environmental issues. However, PBS exhibits the defect of flowing above the melting point and rapid dripping for its poor melt strength. Accordingly, this study proposed a novel method to fabricate PBS vitrimer by exploiting reactive extrusion technology to mix diepoxide with PBS and then by employing zinc acetate as a catalyst to crosslink the PBS. Therefore, after the reaction extrusion blending, the blend still has a lower viscosity and high processing performance; in the subsequent curing process, the polymer undergoes a transesterification reaction and the viscosity increases. Via transesterification to form a cross-linked network, the storage modulus, and loss modulus of PBS vitrimer at 140°C reach 55,800% and 3500% of pure PBS, respectively. At this time, the crystallinity of PBS vitrimer is still as high as 56.9% (The crystallinity of pure PBS is 47.4%). And the shape stability of PBS at high temperatures was significantly improved. Moreover, PBS vitrimer could still be reshaped after the cross-linking process. This study proposed a facile method to produce PBS materials exhibiting high thermal shape stability.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Xin Wang,Binbo Wang,Rong Huang,Tao Jiang,Yi Wang,Shuai Du,Falin Li,Jin Zhu,Songqi Ma
Poly (butylene adipate- co -terephthalate) (PBAT)/starch composites have captured great attentions due to their favorable biodegradability and cost-effectiveness. However, it is still a challenge to prepare PBAT/starch composites with superior mechanical performance, solvent and creep resistance, and gas barrier. This study used a chain breaking-crosslinking strategy to prepare covalent adaptable network (CAN) composites from PBAT and unmodified starch via reactive extrusion. In the chain breaking stage, dipentaerythritol was used to break PBAT via transesterification and capped more hydroxyl groups on PBAT, achieving favorable compatibility with unmodified starch, which is confirmed via infrared spectroscopy analysis and scanning electron microscopy among other experimental methods. In the crosslinking stage, the hydroxyl groups of chain broken PBAT and starch were reacted with styrene-maleic anhydride copolymer (SMA) to form CAN composites. The superior compatibility and network feature gave the composites excellent thermal properties, strength and modulus, creep resistance, solvent resistance and gas barrier performance. Moreover, fast stress relaxation can be achieved based on the transesterification, allowing for extrusion processing and thermal compression molding, demonstrating excellent reprocessing recyclability of the PBAT/starch CAN composites. Overall, this work provides a simple, green and efficient method for preparing high-performance PBAT/starch CAN composites, which should also be suitable for other polymer/filler composites.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）