INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Dequan Han,Huhu Tian,Lantao Liu,Luya Cao,Hongzhang Cao,Xiaoli Yu
The prevalent use of disposable plastic tableware presents notable environmental and health risks. An alternative, polylactic acid (PLA), often does not meet usage requirements due to its low crystallization rate. This research introduces an amide-based nucleating agent, BRE-T-100, developed through a straightforward method to enhance the heat resistance and crystallization rate of PLA. This study systematically investigates the impact of BRE-T-100 and other nucleating agents on the properties of PLA composites. The incorporation of 0.8 % BRE-T-100 increases the crystallization temperature of PLA from 109.6 °C to 131.9 °C. Further, the total crystallization time of PLA composites at 120 °C is reduced to <60 s, while maintaining good transparency. BRE-T-100 exhibits superior comprehensive properties compared to talcum, TMC-200, and TMC-300 and is nearly on par with LAK-301. Its application as a nucleating agent in PLA-based disposable tableware shows promise.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Polymer Materials
·
2020
·
IF 0
Rong Yang,Hongwei Cao,Pengliang Zhang,Li Chen,Guoxiang Zou,Xin Zhang,Jinchun Li
Poly(lactic acid) (PLA) is a well-known sustainable plastic but with an inherent brittleness, slow crystallization rate, and poor heat resistance, which significantly limits its application. In this work, toughened PLA with a balanced tensile strength, fast crystallization rate, and great heat resistance was obtained by dynamic vulcanization with an unsaturated liquid crystalline polyester (PBDPSM) in the presence of a free radical initiator of dicumyl peroxide (DCP). PBDPSM is efficient in enhancing the tensile toughness of PLA in that the elongation at break of PLA significantly increased from 15 to 179% while adding only 1 wt % PBDPSM. When adding 8 wt % PBDPSM, the PLA/PBDPSM8 blend has an elongation at break of 265%, tensile toughness of 107.2 MJ/m3, and notched Izod impact strength of 22.5 kJ/m2. Moreover, it keeps a high tensile strength of 62.6 MPa. In addition, the crystallization rate of PLA has dramatically accelerated due to the apparent nucleation effect induced by DCP and PBDPSM. PLA/PBDPSM3 shows the highest crystallinity with 44.4%. Furthermore, it shows a high Vicat softening temperature of 152.2 °C, which is 92.2 °C higher than that of neat PLA. Finally, highly toughened PLA materials with balanced tensile strength and good heat-resistant properties were realized.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2021
·
IF 6.064
Xiaoling Qu,Guangyuan Zhou,Rui Wang,Haiyan Zhang,Zhipeng Wang,Min Jiang,Jun Tang
In pursuit of poly(ethylene 2,5-furandicarboxylate) PEF materials with high molecular weight, satisfactory appearance and faster crystallization rate, its preparation from dimethyl furan-2,5-dicarboxylate (DMFD) with ethylene glycol (EG) in the trace presence of metal zinc was performed via transesterification method. Optimization of the main polymerization parameters enabled Zn-catalyzed PEF to gain high molecular weight ( M n , 5.40 × 10 4 g mol −1 ) and low content of diethylene glycol furandicarboxylate unit (DEGF, 2.91%). On the basis of experimental phenomena and high performance liquid chromatography (HPLC), the actual catalytic active species of metal zinc in the polymerization was speculated to be a salt of 2, 5-furandicarboxylate derivative (Zn(II)). The in-stiu catalyst can efficaciously inhibit the influence of by-product FDCA on the color of PEF, which displayed quite better appearance (close to white). Differential Scanning Calorimetry (DSC) showed that the in-stiu catalytic system acted as nucleating agent (NA) and the crystallization half-time (t 1/2 ) of PEFs-Zn was only 1/4 of that of PEF-tin. Additionally, series of high molecular weight furan-based polyesters from DMFD and diols with different methylene (3, 5, 6 and 8) were obtained by zinc powder as in-stiu catalyst, which further evidenced it to be efficiency and universality.
研究领域:
材料科学
·
聚合物化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2017
·
IF 3.671
Yongqi Feng,Piming Ma,Pengwu Xu,Ruyin Wang,Weifu Dong,Mingqing Chen,Cornelis Joziasse
The effects of six nucleating agents (NAs), i.e., orotic acid (OA), potassium salt of 3,5-bis(methoxycarbonyl)benzenesulfonate (LAK-301), substituted-aryl phosphate salts (TMP-5), talc (TALC), N' 1 , N' 6 -dibenzoyladipohydrazide (TMC-306) and N 1 , N 1′ -(ethane-1,2-diyl)bis( N 2 -phenyloxalamide) (OXA), on the crystallization behavior of poly(lactic acid) (PLA) were compared by DSC . Under the same dosing of 0.5 wt%, the nucleation effect of the NAs for PLA declines in the order of TMC-306 ≈ OXA > TALC ≫ TMP-5 ≈ LAK-301 ≈ OA. The nucleation efficiency (NE) of TMC-306 and OXA is around 50%, which is almost 2 times of the NE of TALC. In the best case of the PLA/TMC-0.5% sample, the half-time of crystallization decreases from 30 s to 9 s with decreasing the crystallization temperature from 120 °C to 100 °C, which is of great significance to the fast production of highly crystallized PLA materials. As high-efficient NAs, TMC-306 and OXA are able to accelerate the crystallization rate of PLA even upon fast cooling at 50 °C/min, while make no difference on PLA crystal form, as identified by WAXD . DMA analysis shows that the storage modulus of PLA is significantly improved by TMC-306 and OXA.
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
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 141
·期 38
·e55968
·
IF 2.7
Meili Li,Xiancheng Meng,Zaizai Tong
Poly( L -lactic acid) (PLLA), as a green, biodegradable polymer material, has garnered considerable attention due to its ease of processing and exceptional properties. However, the inherent slow crystallization rate and brittleness of PLLA substantially restrict its extensive applications across various domains. In present work, PLLA and poly( D -lactide) (PDLA)-modified cellulose nanocrystals (CNCs), referred as CNC- g -L and CNC- g -D, are serving as nano-fillers to enhance the crystallization rate of PLLA. Our findings demonstrate that both nano-fillers could enhance the crystallization rate of PLLA, but the CNC- g -D shows a more efficient nucleation agent compared with its counterpart, CNC- g -L. Isothermal crystallization analysis indicates that CNC- g -D substantially increases nucleation density of PLLA, with pronounced crystallization at an elevated temperature of 155°C as confirmed by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Wide-angle x-ray diffraction (WAXD) analysis shows the preformation of stereocomplex crystals on the CNC- g -D surface may result in a fast crystallization rate. Meanwhile, after incorporation of different nano-fillers, the toughness property of PLLA has also been significantly enhanced. Our result has shown the CNC- g -D could serve as an efficient nucleation agent toward PLLA and also facilitate to aiding in establishing comprehensive structure–property relationships of polymer materials.
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
Additive Manufacturing
·
2022
·
IF 11.632
Yingshuang Shang,Qinfei Xu,Bo Jiang,Yang Yang,Xin Liu,Zilong Jiang,Chang Yu,Xuefeng Li,Haibo Zhang
The major challenge restricting the application of 3D printed PEEK parts is the weak interlayer strength . Herein, the fluorene-based poly (ether ether ketone)s (FD-PEEK) were designed and synthesized to solve the problem. A remarkable improvement in the interlayer strength of materials was achieved. By introducing 10 mol% fluorene groups into the polymer chain (10 %-FD-PEEK), the interlayer strength of 10 %-FD-PEEK was improved to 41 MPa, which is close to that of the commercial PEEK resin for 3D printing (Victrex, AM 200). The introduction of 15 mol% fluorene groups (15 %-FD-PEEK) enabled the interlayer strength and strain at break of 400 % and 500 % higher than that of PEEK, reaching 67 MPa and 11.23 %, respectively. The improvement of the interlayer strength was attributed to the slower crystallizing rate of FD-PEEK, which was verified by the isothermal and non-isothermal crystallization kinetics . Meanwhile, the chain rigidity caused by fluorene groups and the larger spherulite generated by the slower crystallization allowed FD-PEEK to reach a similar tensile strength to PEEK in the X-axis and Y-axis directions. Achieved by slowing crystallization and introducing rigid structure into the molecular chain , the results significantly promote the engineering application of 3D printing parts and provide new insights into the performance enhancement of semi-crystalline additive manufacturing materials.
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
Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 6
·2613-2618
·
IF 8.867
Chaoqun Bian,Changsheng Zhang,Shuxiang Pan,Fang Chen,Weiping Zhang,Xiangju Meng,Stefan Maurer,Daniel Dai,Andrei-Nicolae Parvulescu,Ulrich Müller,Feng-Shou Xiao
As a class of important catalysts and adsorbents, zeolites are normally prepared through hydrothermal synthesis, whereby a relatively long crystallization time and use of a large amount water solvent strongly hinder the enhancement of zeolite space-time yields (STYs), which is a critical factor for the industrial manufacturing. To overcome this limitation, herein we report a novel strategy for highly efficient zeolite synthesis by means of fast crystallization at high temperatures (200–240 °C) in the absence of water solvent. This concept significantly enhances the crystallization rates and allows drastic reduction of the time required for crystallization of the zeolite frameworks such as the crystallization of MFI from 12–24 h at 180 °C to 0.5 h at 240 °C and RUB-36 from 14 days at 140 °C to 1.5 days at 200 °C. Together with much better utilization of the reactor volume, the space-time yields (STYs) for zeolites prepared from high-temperature synthesis in the absence of water solvent can be remarkably increased. The STYs of MFI and RUB-36 are as high as 11 000 and 178 kg m−3 per day, which are almost two orders of magnitude higher than those of conventional hydrothermal synthesis. This novel synthesis method should be applicable for synthesizing a wide variety of zeolite structures and bears the potential for highly efficient zeolite synthesis on an industrial scale.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
AICHE JOURNAL
·
2024
·
IF 3.5
Fan Zhou,Yanling Chen,Zhengqing Zhang,Zhenjie Gu,Yuxiu Sun,Minman Tong,Qingyuan Yang,Wenjun Dong,Yichang Pan,Zhihua Qiao,Chongli Zhong
Metal–organic framework (MOF) membranes are widely used in gas separation processes. However, the effect of solvents on the formation of large-area MOF membranes, which directly influences separation performance, has rarely been investigated. In this study, three solvents (methanol, ethanol, and water) were selected to systematically investigate their effects on the zeolite imidazolium frameworks (ZIF) membrane formation via experimental validation and simulations. The results indicated that the solvent selection influenced crystallization rate, crystal size, and ZIF-8 membrane formation ability. Particularly, when water was used as a solvent, slow nucleation and crystallization of the ZIF-8 crystals were observed, resulting in a more complete crystal structure and a thinner ZIF-8 membrane. Therefore, the ZIF-8 membrane exhibited a gas permeance of 10,000 gas permeation unit and enhanced CO 2 /N 2 selectivity. Furthermore, ZIF-8 membrane with a surface area of 2400 cm 2 and spiral-wound membrane modules were developed, paving the way for large-scale industrial production.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2024
·
IF 3.3
Jiaojiao Yu,Yi Zuo,Gudan Li,Hong Yang,Xinwen Guo
To synthesize a high-performance titanium silicalite-1 (TS-1), this paper reports a simple and environmentally friendly approach to regulate the alkalinity in the synthesis of titanium silicalite-1 (TS-1) involving tetrapropylammonium hydroxide (TPAOH) and tetrapropylammonium bromide (TPABr). Essentially, the pH of the synthesis gel was controlled by n(TPAOH/TPA+), while keeping the total tetrapropylammonium cations (TPA+) constant. The study shows that at a relatively moderate alkalinity of pH = 10.7, TS-1 produced exhibits nanocrystalline microstructure favorable for diffusion, contains high contents of TiO4 and TiV, and delivers 94.3% of H2O2 conversion with a turnover frequency of 565.6 mol (mol h)−1 in propylene epoxidation. Through detailed analysis of crystallization processes of TS-1 at different alkalinities, this study unveils the effect of alkalinity on the rate of Si–Ti condensation, which dictates the formation of the framework structure and incorporation of Ti species into the framework. Essentially, only at moderate alkalinity of pH = 10.7, comparable Si–OH and Ti–OH condensation rates permit the highest amount of Ti being inserted in TS-1 as active (TiO4 + TiV) and limits the self-condensation of Ti species to form inactive anatase-TiO2.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PAPERS
·
2021
·Vol. 75
·期 12
·6399-6406
·
IF 2.097
Yao Lihui,Wang Yajuan,Li Ya,Jiang Zhiqiang,Qiu Dan
A series of Fe 3 O 4 /PLA composites are controllably prepared using consecutive reaction route. The neat PLA and its composites are characterized by FT-IR, WAXRD and XPS for composition analysis. The performances of PLA and Fe 3 O 4 /PLA composites are, respectively, determined by SEM, VSM, CAM, POM, DSC and TG. Fe 3 O 4 particles are a good dispersion in the PLA matrix, and the saturation magnetization values of PLA have increased from 0.33 to 5.06 emu/g. When PLA is transformed into composites, the mean thickness of composites has decreased and water contact angle of composites has increased due to heavy and hydrophobicity Fe 3 O 4 . After addition of Fe 3 O 4 particles, the 50 k, 100 k and 200 k PLA’s crystallization rate is severally increased to 1.84, 1.56 and 1.44 times. It is concluded that the Fe 3 O 4 particles are the efficient crystallization nucleating agent of PLA and faster accelerate the crystallization of low molecular weight PLA in comparison with high molecular weight PLA. The melting points of Fe 3 O 4 /PLA composites slightly have decreased compared with the neat PLA, which is in accord with the melting point of the mixture that is lower than that of the pure substance. By introducing 5 mass% of Fe 3 O 4 particles to PLA, the initial decomposition temperatures reached to higher temperatures as compared to the neat PLA, and the final char yield is about 4.60%. The well dispersion of the particles in the PLA matrix is thought to be an effective barrier to the permeation of heat, which would improve the thermal stability.
研究领域:
材料科学
·
聚合物工程
✓ 已验证
产品关联
DOI
高影响因子
FIBERS AND POLYMERS
·
2020
·Vol. 21
·期 7
·1550-1559
·
IF 1.797
Mahmud Sakil,Long Yu,Abu Taher Muhammad,Hu Han,Zhang Ruoyu,Zhu Jin
Poly(butylene 2,5-furandicarboxylate) (PBF) derived from 2,5-furandicarboxylic acid (FDCA) is an emerging bio-based alipharomatic polyester that is expected to replace its fossil-based terephthalate and naphthate homologues. PBF holds excellent gas barrier properties, but its slow rate of crystallization might restrict wider applications. To improve the rate of crystalization, it was melt-blended with crystalline micro-cellulose (CMC) to prepare a composite through twin-screw extrusion. To ensure environmental friendly conditions, neither chemicals to modify fibers nor compatibilizers to improve the filler/matrix interaction were used. Size exclusion chromatography (SEC), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and X-ray diffraction (XRD) were used to characterize the composite. It was observed that a longer blending duration (cyclic mode) leads to a greater reduction in molecular weight (Mw) in the presence of CMC, which can be avoided by using a shorter blending duration (direct mode). The mechanical properties of the composite showed an increase in Young’s modulus by approximately 23 % and 36 % with respect to reference PBF for the cyclic and direct mode respectively. It was further observed that, although the elongation at break and tensile strength has decreased, it has improved gas barrier properties. Thermal analysis shows faster nucleation of PBF in the presence of CMC with a minor effect on its thermal degradation.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2016
·
IF 2.567
Jianxiang Chen,Qiaolian Lv,Defeng Wu,Xin Yao,Jun Wang,Zhaoshun Li
Crystallization control of the hard polyester segments is an important way to design the final properties of a thermoplastic polyester elastomer (TPEE). In this work, the crystallization behavior of TPEE with nanosilica as the nucleating agent was studied. Three kinds of nanosilica with various sizes and surface treatments were chosen for nucleation design. The results reveal that all types of nanosilicas have evident nucleating effects, leading to a remarkable increase of the crystallization temperature of TPEE even by about 30 °C. However, the overall crystallization process is highly dependent on the particle size and surface treatment of silica because it is closely related to the nucleation ability of the particles and alteration of the system viscosities. The crystallization temperature of TPEE is more sensitive to the surface treatment of silica, while its crystallization rate shows a higher dependence on the particle size of silica. This work provides a facile way to well tailor crystallization of TPEE.
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
危险品化学品经营许可证（带存储）