POLYMER DEGRADATION AND STABILITY
·
2024
·
IF 6.3
Qing-Qing Bi,Ying-Ming Li,Lu He,De-Yi Wang
Although epoxy asphalt (EA) mixtures have been widely used for the pavement in tunnels, it was limited by its flammability, poor compatibility and low mechanical property. To solve the above problems, a compatibilized and toughening flame retardant (ESO-AA-DOPO) was prepared via the epoxidized soybean oil (ESO), arachidonic acid (AA) and 9,10-Dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO). The presence of ESO-AA-DOPO significantly improved the flame retardancy, in which passing the UL-94 V-2 rating. The peak heat release rate (PHRR) reducing by 46.2 % for EA/40A-ESO-AA-DOPO composites comparing to that of pure EA. The analysis of char residue confirmed that the catalytic formation of dense and continuous char layer residue with good thermal oxidation stability originating from the ESO-AA-DOPO. The initial stage viscosity of ESO-AA-DOPO modified EA was lower than that of pure EA. Under the action of aliphatic epoxy resin and double bond, the molecular chain of epoxy resin presented a network structure, the base asphalt was divided into micelles, and the overall distribution of EA system was a 3D networks “sea-island”, which ensuring the increase in the glass transition temperature (Tg) of the EA system. The tensile strength and elongation at break of EA/40A-ESO-AA-DOPO composites were 123 % and 207 % higher than those of pure EA attributing to the improved compatibility and the formation of 3D networks “sea-island” structure.
研究领域:
材料科学
·
土木工程
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2022
·Vol. 12
·期 2
·210
·
IF 2.67
Xingyuan Diao,Xiaonan Chen,Shihao Deng,Hongwei Bai
Stereocomplex-type polylactide (SC-PLA) created by alternate packing of poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA) chains in a crystalline state has emerged as a growingly popular engineering bioplastic that possesses excellent hydrolytic stability and thermomechanical properties. However, it is extremely difficult to acquire high-performance SC-PLA products via melt-processing of high-molecular-weight PLLA/PDLA blends because both SC crystallites and homocrystallites (HCs) are competitively formed in the melt-crystallization. Herein, a facile yet powerful way was employed to boost SC formation by introducing trace amounts of some epoxy-functionalized small-molecule modifiers into the enantiomeric blends during reactive melt-blending. The results show that the SC formation is considerably enhanced with the in situ generation of multi-arm stereo-block PLA copolymers, based on the reaction between epoxy groups of the modifiers and hydroxyl end groups of PLAs. More impressively, it is intriguing to find that the introduction of only 0.5 wt% modifiers can induce exclusive SC formation in the blends upon isothermal and non-isothermal melt-crystallizations. The outstanding SC crystallizability might be attributed to the suppressing effect of such unique copolymers on the separation of the alternately arranged PLLA/PDLA chain segments in molten state as a compatibilizer. Furthermore, the generation of these copolymers does not result in a significant increase in melt viscosity of the blends. These findings suggest new opportunities for the high-throughput processing of SC-PLA materials into useful products.Keywords:polylactide;stereocomplex;crystallization;copolymer;compatibilization
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 APPLIED POLYMER SCIENCE
·
2021
·Vol. 138
·期 47
·51413
·
IF 3.125
Rong Yang,Hongwei Cao,Chong Li,Guoxiang Zou,Xin Zhang,Jinchun Li
Reactive interfacial compatibilization is the most efficient way to prepare super-tough poly (lactic acid) (PLA) materials. Introducing a post-reactive group into a toughening agent that can react with PLA is the key issue. Herein, we reported a series of fully bio-based polyesters (PBSePM) synthesized with sebacic acid, diethyl malate, 1,3-propanediol, and 1,4-butanediol via transesterification in one pot. Super-tough PLA materials can be obtained by reactively blending with PBSePM in the presence of hexamethylene diisocyanate (HDI). In the processing, the side hydroxyl group of the PBSePM reacted with HDI and formed polyurethane elastomer to improve the toughness of PLA. Moreover, the in-situ formed PLA- g -PBSePM grafted copolymer enhanced the interfacial adhesion. With increasing diethyl malate moiety in PBSePM, the PBSePM phase morphology transformed from co-continuous phase structure to semi-continuous and “sea-island” phase structure. When adding 20 wt% PBSePM, all PLA/PBSePM blends have a notched impact strength higher than 53 kJ m −2 , suggested a super toughness effect. Maximum impact strength of 83 kJ m −2 was realized while the PBSePM containing 20% diethyl malate moiety. In addition, super-tough PLA materials can be achieved by only adding 15 wt% PBSePM20, exhibited a highly efficient toughening effect.
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
POLYMER TESTING
·
2023
·
IF 5.1
Minzimo Song,Shenghua Li,Guiyou Zhu,Jianwei Guo
It is valuable research to improve the compatibility and toughness of PLA/PCL blends while endowing them with shape memory & 4D printing capability. In this work, lactic acid/caprolactone-modified chitosan (mCS) was used to connect the amorphous region of PLA and PCL to achieve compatibilisation, toughening and 4D printing shape memory ability. The effects of different mCS additions on the morphology, crystalline behaviour, and thermal properties of PLA/PCL blends were observed to study the mechanism of compatibilisation and toughening. Adding 0.5 g mCS into 10 g PLA/PCL blends had the best compatibilisation and toughening effect. At the same time, the blends with this addition ratio had the best shape memory performance after 4D printing. The shape fixity and shape memory ratios of the 4D printing model were as high as 100% and 94.5%, respectively. This work provides a new way to fabricate biomedical devices and bionic components with 4D printing.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Jianfeng Fan,Jiarong Huang,Liming Cao,Shiheng Yin,Yukun Chen
Recyclable polyvinylidene fluoride/silicone rubber (PVDF/SR) thermoplastic vulcanizates (TPVs) containing a high mass ratio of SR (50%) with excellent mechanical performances and shape memory behavior were fabricated. The inert PVDF was first dehydrofluorinated via β-H elimination reaction to introduce reactive double bonds. Then, the functional groups were initiated by dicumyl peroxide (DCP) during dynamic vulcanization to realize interfacial grafting (SR-g-PVDF) simultaneously. In situ grafted PVDF chains tightly bridge the immiscible phases, leading to the excellent interfacial adhesion. Consequently, the tensile strength, elongation at break, and tensile toughness were significantly increased to 14.5 MPa, 174.6%, and 12.3 kJ/m3, respectively, which were almost 2.0, 13.6, and 10.3 times than that without interfacial grafting reaction (7.2 MPa, 12.8%, and 1.2 kJ/m3). Also, their excellent mechanical properties were almost perfectly maintained after multiple repetitive processing. Furthermore, the chemical anchoring structure of SR-g-PVDF across the interface could effectively and quickly transfer the force, contributing to the shape memory performances. The obtained TPVs (m60 and m80) showed an impressive shape recovery ratio (>80%) even after two fixing-recovery cycles.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2021
·Vol. 30
·期 3
·1127-1140
·
IF 3.667
Wang Jun,Yang Le,Li Xiaolong,Luo Zhu,Li Jianjun,Xia Xiaosong,Linghu Changkai
Incompatible polypropylene (PP) and polyethylene (PE) are difficult to separate in mixed recycling streams such as waste plastic packaging, which makes polyolefin mixtures unsuitable for high-quality products. In this work, based on the free radical branching reaction, a co-branching reaction of isotactic polypropylene (iPP) and high-density polyethylene (HDPE) blends was carried out in the presence of the peroxide, free radical regulator and multifunctional acrylate monomer, and a star-like long-chain branching (LCB) copolymer was obtained. The effect of in situ compatibilization on the structures and mechanical properties of iPP/HDPE was investigated, and the compatibilization mechanism was discussed. Results showed that the mechanical properties of the modified blends were largely improved, and efficient in-situ compatibilization of iPP and HDPE could be taken place in a wide process window. Moreover, the sizes of the dispersed phase in the modified blends were clearly decreased, and the interfacial thickness increased. Compared with the pure iPP/HDPE blend, the initial crystallization temperature of iPP in the modified iPP/HDPE blend was increased, and long branched chains of the LCB copolymers were physically entangled with the chemical identical homopolymers or even participated in the crystallization of iPP and HDPE. Thanks to the in situ compatibilization strategy, the compatibility of iPP/HDPE was significantly improved.
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
JOURNAL OF APPLIED POLYMER SCIENCE
·
2025
·
IF 2.8
Mengmeng Xu,Chengzhong Zong
It is challengeable to obtain shape memory effect in the traditional thermoplastic vulcanizate (TPV) with sea-island microstructure. Herein, we successfully achieved shape memory behavior in the type of ethylene propylene diene monomer/polypropylene thermoplastic vulcanizate (EPDM/PP TPV) compatibilized by the graft products of magnesium maleic (MgMA) and maleic anhydride (MAH) on the interface of EPDM/PP. MgMA and MAH derived from the in situ neutralization reaction of maleic acid (MA) with magnesium oxide (MgO) and the dehydration reaction of MA respectively. In this paper, the mole ratio of MA and MgO on the performance of EPDM/PP TPV was studied. With the incorporation of MA and MgO, the mechanical property and shape memory performance were improved. The result of DMA, FTIR, and SEM verified the successful graft reaction of MgMA and MAH on the polymer chains. The compatibilized EPDM/PP TPV achieved the improved mechanical property of tensile strength (12.9 MPa) and elongation at break (583.5%), the increased R f of 96.2% and R r of 86.7% at the tailoring mole ratio of MA:MgO (1:1.5).
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
POLYMER TESTING
·
2018
·
IF 2.247
Wenqi Wang,Zhiwei Bai,Shiping Zhang,Jiahong Guo,Ting Wei,Jikui Wang
Styrene maleic anhydride (SMA)-g-APA6 copolymer was firstly synthesized by free radical polymerization of styrene and followed by anionic polymerization of ε-caprolactam. The polyamide 6 (APA6)/polystyrene (PS) blends were successfully prepared via anion polymerization. Among in, SMA was acted as both compatibilizer and macromolecular activator. A series of APA6/PS blends with different SMA addition amounts were synthesized to study the effect of SMA on crystallinity , morphology, water resistance, thermal stability and mechanical properties using X-ray diffraction analysis, differential scanning calorimetry , scanning electron microscopy analysis , contact angle measurement, water absorption measurement, molau test, thermogravimetric analysis , stretching and impact test. Correlational analysis proved that the obtained SMA-g-APA6 copolymer has good dispersion with PS. In addition, APA6/PS blends possess good mechanical properties, thermostability and hydrophobic property.
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
COMPOSITES PART B-ENGINEERING
·
2022
·
IF 11.322
Shulong Zeng,Dinghao Xu,Qin Yang,Huan Zhang,Hui Zhao,Lirong He
Elastic materials based on biomass fiber reinforced natural rubber (NR) composites featured by renewability, environmental friendliness, and outstanding toughness have attracted intensive attention. However, the improvement in tensile strength via natural fiber reinforcement is always accompanied by the compromise in toughness, which is rooted in the notoriously weak interfacial bonding originating from the significant mismatch in surface energies between constituent materials. In this work, we for the first time present a facile route to realize the interfacial activation of keratin fibers (KFs) derived from leather solid waste as well as the preparation of NR/KF composite with dual excellence in tensile strength and toughness via mechanochemistry. The activated thiol groups generated by mechanochemical pulverization promote the dispersion and in-situ compatibilization of KFs in rubber matrix , thereby facilitating effective interfacial stress transfer and enhancing the mechanical performance of the composites. As a result, the tensile strength, elongation, and toughness at break of composite elastomer reach 19.4 MPa, 781.0%, and 48.8 MJ/m 3 , respectively, outperforming the state-of-the-art natural fiber reinforced NR composites. Moreover, the incorporation of mechanochemical-pulverized KFs into NR matrix offers heterogeneous nucleation locales, facilitating the foaming of NR in supercritical carbon dioxide (ScCO 2 ). The cell wall of the composite is in turn reinforced, and the resultant foam manages to deliver an excellent compressive recovery rate of 99.4% even after 200 cycles that outstrips those of reported foams. This work highlights a facile and green route to turn waste bovine hair in leather industry into high-performance bio-based elastomer and super-elastic foam.
研究领域:
材料科学
·
环境科学
·
生物材料
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Xinyi Dong,Li Liu,Yang Wang,Ting Li,Zhenggui Wu,Hao Yuan,Piming Ma,Dongjian Shi,Mingqing Chen,Weifu Dong
A novel core-shell starch-based nanoparticles (CSS NPs) with a “hard” starch core and a “soft” poly (methyl acrylate) (PMA) shell was prepared and incorporated into a PPC/PLA blend. The excellent compatibilization of CSS NPs was revealed by atomic force microscope (AFM), differential scanning calorimetry (DSC) and rheological test. More importantly, due to the excellent compatibilization the resulted PPC/PLA/CSS blend exhibited a strikingly improved mechanical and thermal properties. Compared to PPC/PLA (60/40), the elongation at break of PPC/PLA/CSS (60/40/20) increased greatly from 15 % to 272 % without sacrificing the tensile strength. Besides, the heat distortion temperature (HDT) of PPC/PLA/CSS (60/40/20) was improved to 47.3 °C, which was 20.5 °C higher than that of the neat PPC . These results established a novel and efficient strategy to improve the compatibility of polymer blends and to prepare polymer blends with balanced toughness and stiffness.
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
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2025
·Vol. 36
·期 4
·e70183
·
IF 3.4
Shiji Gao,Chong Yu,Xiaopei Li,Enming Huang,Shiyu Wang,Xuanwei Zhang,Yongjie Zhang
Recycling of discarded polyolefins is vital to reducing dependence on oil, promoting resource sustainability, and achieving a closed-loop economy. Direct recycling without time- and labor-consuming sorting is an efficient and economical approach to the treatment of polyolefins from mixed waste streams. However, the immiscibility of different polyolefins would lead to severe phase separation and inferior properties of generated blends. To solve this problem, an acyloxyimide-based initiator, namely N -acetoxy-phthalimide (NAPI), was utilized to in situ generate graft copolymers and grafted/functionalized polyolefins via a simple, one-step, and scalable reactive blending approach. Compared to traditional peroxide initiators, NAPI is a more efficient H-abstracting agent while avoiding undesired side reactions (β-scission and cross-linking). The in situ resultant graft copolymers and grafted/functionalized polyolefins serve as efficient compatibilizers that considerably enhance the compatibility of binary isotactic polypropylene ( i PP) and polyethylene (PE) blends by reducing interfacial tension and, consequently, improving the mechanical properties of mixed polyolefin blends. The presence of i PP-PE graft copolymer was solidly evidenced by infrared spectroscopy analyses. Compared to the control i PP/PE blend, the elongation at break, impact strength, and bending modulus of the modified i PP/PE blend increased by 471.7%, 21.5%, and 45.7%, respectively.
研究领域:
材料科学
·
环境工程
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER COMPOSITES
·
2024
·
IF 4.8
Yinan Yan,Bianying Wen
Using polymer-grafts to improve the interfacial compatibilization of composites is by far the most common and effective strategy. However, although polybutene-1 (PB) resin enjoys the reputation of “gold plastic” in the field of industry, there are few studies on its grafting and functional modification. In this work, PB-grafts were prepared by melt grafting method with maleic anhydride (MAH) and styrene (St) as the functional monomers. The effect of two PB-grafts (PB-g-MAH and PB-g-MAH-co-St) on the interfacial compatibilization of PB/GNP (Graphene nanosheet) thermally conductive composites was compared and the corresponding compatibilizing mechanism is discussed. Results indicate that PB-g-MAH-co-St has better compatibizing effect than that of PB-g-MAH because the cooperation of St with MAH enhanced the grafting degree of functional monomers on PB, and increased the surface energy of PB-g-MAH-co-St, which reduced the interface energy between PB and GNP and improved its interfacial adhesion. A better compatibilization effect has achieved when the compatibilizer and filler at the mass ratio of 1:4. Under this ratio, when the content of GNP is 30 wt%, the thermal conductivity and electrical conductivity of PB/GNP/ PB-g-MAH-co-St composite achieved 1.82 W·m −1 ·K −1 and 8.44 × 10 −8 S·cm −1 , which are 857.89% and 9 orders of magnitude higher than that of neat PB, respectively. Moreover, the composite has good mechanical properties and processability, which is beneficial to industrialization. Highlights PB-g-MAH-co-St has higher grafting ratio than that of PB-g-MAH. The surface energy of PB/GNP composites is reduced by use of PB-g-MAH-co-St. There is a suitable mass ratio between compatibilizer and filler. The composite of PB/GNP/PB-g-MAH-co-St achieved high thermal conductivity. The PB/GNP/PB-g-MAH-co-St composites have good melting processability.
研究领域:
材料科学
·
高分子科学
·
复合材料
✓ 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）