Polymers
·
2022
·Vol. 14
·期 10
·2039
·
IF 4.967
Ziyun Shen,Liuchun Zheng,Danqing Song,Yi Liu,Chuncheng Li,Jiajian Liu,Yaonan Xiao,Shaohua Wu,Tianbo Zhou,Bo Zhang,Xuedong Lv,Qiyong Mei
A series of non-isocyanate poly(ether urethane) (PEU) were prepared by an environmentally friendly route based on dimethyl carbonate, diols and a polyether. The effect of the chemical structure of polyurethane hard segments on the properties of this kind of PEU was systematically investigated in this work. Polyurethane hard segments with different structures were first prepared from hexamethylene di-carbamate (BHC) and different diols (butanediol, hexanediol, octanediol and decanediol). Subsequently, a series of non-isocyanate PEU were obtained by polycondensation of the polyurethane hard segments with the polyether soft segments (PTMG2000). The PEU were characterized by GPC, FT-IR,1H NMR, DSC, WAXD, SAXS, AFM and tensile testing. The results show that the urea groups generated by the side reaction affect the degree of crystallization of hard segments by influencing the hydrogen bonding of the hard segments molecular chains. The degree of hard segment crystallization, in turn, affects the thermal and mechanical properties of the polymer. The urea group content is related to the carbon chain length of the diol used for the synthesis of hard segments. When butanediol is applied to synthesize hard segment, the hard segment of the resulting PEU is unable to crystallize. Therefore, the tensile strength and modulus of elasticity of butanediol-based PEU is lowest among three, though it possesses the highest urea group content. When longer octanediol or decanediol is applied to synthesize the hard segment, the hard segments in the resulting polyether-based polyurethane are crystallizable and the resulting PEU possesses higher tensile strength.Keywords:non-isocyanate;poly(ether urethane);hard segment
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
CHINESE JOURNAL OF POLYMER SCIENCE
·
2025
·
IF 4
Jin Guang-Zhi,Chen Le-Hang,Gong Yu-Zhen,Li Peng,Wang Run-Guo,Li Fan-Zhu,Lu Yong-Lai
The fatigue resistance of casting polyurethane (CPU) is crucial in various sectors, such as construction, healthcare, and the automotive industry. Despite its importance, no studies have reported on the fatigue threshold of CPU. This study employed an advanced Intrinsic Strength Analyzer (ISA) to evaluate the fatigue threshold of CPUs, systematically exploring the effects of three types of isocyanates (PPDI, NDI, TDI) that contribute to hard segment structures based on the cutting method. Employing multiple advanced characterization techniques (XRD, TEM, DSC, AFM), the results indicate that PPDI-based polyurethane exhibits the highest fatigue threshold (182.89 J/m 2 ) due to a highest phase separation and a densely packed spherulitic structure, although the hydrogen bonding degree is the lowest (48.3%). Conversely, NDI-based polyurethane, despite having the high hydrogen bonding degree (53.6%), exhibits moderate fatigue performance (122.52 J/m 2 ), likely due to a more scattered microstructure. TDI-based polyurethane, with the highest hydrogen bonding degree (59.1%) but absence of spherulitic structure, shows the lowest fatigue threshold (46.43 J/m 2 ). Compared to common rubbers (NR, NBR, EPDM, BR), the superior fatigue performance of CPU is attributed to its well-organized microstructure, polyurethane possesses a higher fatigue threshold due to its high phase separation degree and orderly and dense spherulitic structure which enhances energy dissipation and reduces crack propagation.
研究领域:
材料科学
·
力学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Liqian Zhu,Liang Zhu,Jijiang Hu,Zhen Yao,Zhiyang Bu,Suyun Jie,Bo-Geng Li
Polyurea elastomers with excellent mechanical properties are widely used in a variety of applications due to the unique microphase separation structure and high flexibility in formulations. A key point in the development of polyurea elastomers is to explore the structure–property relationship. However, few studies have focused on the effect of soft segment structures because of the limitation that the flexible soft segments are usually commercialized amine-terminated polyether. Herein, a series of polybutadiene-based polyurea elastomers were prepared to systematically investigate the influence of the network structures on the ultimate properties of the polyurea materials. In particular, the amine-terminated liquid polybutadiene rubber with tunable molecular weights and liquid polystyrene–butadiene rubber were synthesized via the degradation method for flexible regulation of the soft segment structure. The results demonstrated that performance optimization could be achieved by manipulating the degree of hydrogen bonding, which was controlled by the network structure. Besides, the polybutadiene-based polyurea elastomers exhibited excellent low-temperature properties, owing to the high cis-1,4 content.
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
EUROPEAN POLYMER JOURNAL
·
2021
·
IF 4.598
Zhengkai Wei,Zhimeng Liu,Xiaowei Fu,Yuechuan Wang,Anqian Yuan,Jingxin Lei
A series of solvent-free waterborne polyurethanes (WPUs) with different soft segment structure were prepared by respectively using different number-average molecular weight ( M n ) of polytetramethylene glycol (PTMG, M n = 1000, 2000, 3000) and poly (1,4-butylene adipate) (PBA, M n = 1000, 2000 3000) as main diol in this paper. Effect of soft segment crystallization on water resistance of WPUs was discussed. The crystallization properties of WPU films were investigated by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The water resistance was determined by water absorption ratio. DSC and XRD results confirm that there are no crystalline structures in the WPU films which are synthesized with PTMG ( M n = 1000, 2000, 3000) and PBA ( M n = 1000), while the WPU films synthesized with PBA ( M n = 2000 and 3000) have obvious crystalline structures at room temperature. Meanwhile, the WPU films synthesized with PBA ( M n = 2000 and 3000) possess excellent water resistance because the existence of crystalline structure.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2015
·Vol. 51
·期 5
·2727-2738
·
IF 2.371
Wu Xiwen,Liu Libin,Fang Wenyuan,Qiao Congde,Li Tianduo
Abstract In this work, we synthesized two kinds of polyurethanes with azobenzene as hard segments in the side chains and in the main chains. Their thermal stabilities were high enough for their shape memory application. For polyurethane with azobenzene in the side chain (PU), the azobenzene has more distinctly effect on inhibiting crystallization of polycaprolactone (PCL) because of irregular orientation of azobenzene. For polyurethane with azobenzene in the main chain (PUR), the crystallinity of PCL is mainly affected by its molecular weight. PU-3500 and PUR-3500 exhibit perfect shape fixing ability of 99 % with recovery ratio of 98 % at 50 % strain. The recovery ratio is decreased for PU-3500 and increased for PUR-3500 as the applied strain increased. The mechanism of the hard segment structures effect on the shape memory behavior is briefly discussed. Importantly, the two molecules behave trans–cis isomerization under UV irradiation. This work is crucially important for the structural design of shape memory polyurethane and applications in the smart devices. Graphical Abstract
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
Materials
·
2020
·Vol. 13
·期 21
·4991
·
IF 3.057
Xin Jin,Naisheng Guo,Zhanping You,Yiqiu Tan
Thermoplastic polyurethane elastomers (TPUs) are widely used in a variety of applications as a result of flexible and superior performance. However, few scholars pay close attention on the design and synthesis of TPUs through the self-determined laboratory process, especially on definite of chemical structures and upon the influence on properties. To investigate the properties of synthesized modifier based on chemical structure, firstly each kind of unknown structure and composition ratio of TPUs was determined by using a new method. Furthermore, the thermal characteristics and mechanical properties of modifiers were exposed by thermal characteristics and mechanics performance tests. The experimental results indicate that TPUs for use as an asphalt modifier can successfully be synthesized with the aid of semi-prepolymer method. The linear backbone structure of TPUs with different hard segment contents were determined by micro test methods. The polyester-based TPUs had thermal behavior better than the polyether-based TPUs; conversely, the low temperature performance of polyether-based TPUs was superior. Most importantly, it was found that the relative molecular mass of TPUs exhibited a weak effect on the mechanical properties, whereas the crystallinity of hard segment showed a significant influence on the properties of TPUs.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Polymers
·
2021
·Vol. 13
·期 8
·1270
·
IF 4.329
Mengyuan Zhang,Zhonghua Chang,Xiaofeng Wang,Qian Li
Biodegradable and bioabsorbable polymers have drawn considerable attention because of their mechanical properties that mimic human soft tissue. Poly(l-lactide-co-ε-caprolactone) (PLCL), the copolymer of L-lactic (LA) and ε-caprolactone (CL), has been applied in many tissue engineering and regenerative medicine fields. However, both the synthesis of PLCL and the structure-activity relationship of the copolymer need to be further investigated to allow tuning of different mechanical properties. The synthesis conditions of PLCL were optimized to increase the yield and improve the copolymer properties. The synthetic process was evaluated by while varying the molar ratio of the monomers and polymerization time. The mechanical properties of the copolymer were investigated from the macroscopic and microscopic perspectives. Changes in the polymerization time and feed ratio resulted in the difference in the LA and CL content, which, in turn, caused the PLCL to exhibit different properties. The PLCL obtained with a feed ratio of 1:1 (LA:CL) and a polymerization time of 30 h has the best toughness and elasticity. The developed PLCL may have applications in dynamic mechanical environment, such as vascular tissue engineering.Keywords:poly(l-lactide-co-ε-caprolactone);synthesis;segment;toughness;elasticity
研究领域:
生物材料学
·
组织工程学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2020
·
IF 4.469
Yujie Wang,Lili Wang,Hao Liu,Suqin He,Xuying Liu,Wentao Liu,Miaoming Huang,Chengshen Zhu
Development of smart polyurethane (PU) coatings for enhancing the biocompatibility of the metal scaffold has attracted great interest in the past few years, and the investigation of the relationship between phase structure and smart properties is necessary. Herein, two series of PU biocoatings with different hard segment structures and soft segment length were prepared, and the soft segments consist of the polycaprolactone diols (PCL) with different molecular weights, and the hard segments were made of 1, 4-butanediol (BDO) and hexamethylene diisocyanate (HDI) with linear structure, or BDO and isophorone diisocyanate (IPDI) with alicyclic structure, respectively. To understand the phase structures, the chemical structure, surface micromorphology, and segmental incompatibility of the PU films were characterized, which reveals that IPDI-based PU possesses a phase compatible structure with a single-phase transition above 0 °C. Besides, the IPDI-based PU shows the thermal-responsive deformation at the temperature of 45 °C, slightly higher than the human body temperature. In contrast, the HDI-based PU possesses the excellent shape memory property caused by the microphase separation structure, because of the crystallization of soft and hard segments from the melt. Further, based on the characteristics of phase structure, the potential application of the IPDI-based PU and HDI-based PU is explored, offering a useful approach to effectively design the structures and properties of PU coatings.
研究领域:
生物材料学
·
高分子化学
·
医学工程
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Polymer Science
·
2018
·
IF 1.718
Xin Wang,Pin Chen,Xiaohong Hu
The focus of nanoparticle research is on exploring its application in all kinds of field. Among these, multifunctional nanoparticle attracts increasing interest due to its fittest property and adjustable property. Herein, a multifunctional and multistage nanoparticle considering the advantage of both nanogel and pH-responsive property has been designed and synthesized in the research. The composite nanoparticle was obtained by in situ processing and polymerization technique using acetylated β-cyclodextrin and gelatin as materials. Gelatin was first encapsulated into Ac-β-CD nanoparticle in order to investigate optimal fabrication conditions of W/O/W technique. The results showed that the nanoparticle had monodisperse characteristic and coarse spherical morphology, which was influenced by factors such as PVA concentration and water/oil ratio. In further step, two-phase composite nanoparticle could be obtained by combined W/O/W technique and in situ polymerization using optimal preparative parameters of W/O/W technique. Two-phase structure could be confirmed by TEM images and DLS results. Fabrication temperature had no effect on the diameters of composite nanoparticle, but influenced the encapsulated efficiency of nanogel. Finally, composite nanoparticle showed quick pH response property at mild acid medium and no obvious cytotoxicity.
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
Advanced Industrial and Engineering Polymer Research
·
2019
·
IF 0
Jiaxiang Qin,Junqiao Jiang,Shuxian Ye,Jiaxin Liang,Youji Tao,Shuanjin Wang,Dongmei Han,Min Xiao
As carbon dioxide (CO 2 ) is an inexpensive, abundant, sustainable and green carbonyl resource, its utilization to produce value-added chemicals and polymeric materials has attracted much more attention. In this work, a novel CO 2 route polyurea (PUa) was synthesized. The chemical composition, molecular structure, and aggregation structure of polyurea has been confirmed by 1 H-NMR, HMBC-NMR, DSC, TG, MALDI-TOF MS and POM. The result from POM shows that polyurea gives out a spherulitic morphology, exhibited a typical black cross pattern formed by many concentric circles with different light and shade. Moreover, shape memory polymers of polyurea-multiblock-poly(propylene carbonate) (PUa- mb -PPCs) with a M n nearly 4.72 × 10 4 Da and a polydispersity index (PDI) of 1.51–1.64 were synthesized by chain extension of the polyurea with CO 2 derived poly(propylene carbonate) diols (PPC-OH). The PUa- mb -PPCs possess high strength and elasticity because the crystallinity formed by polyurea and amorphous region from PPC. Notably, excellent shape memory effect (SME) is observed in shape thermomechanical testing. The present work provides a simple and renewable process for the synthesis of CO 2 -copolymer with multiblock structure, opening a new route for preparation of functional polymeric materials from carbon dioxide conversion.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
DOI
Polymer Chemistry
·
2021
·Vol. 12
·期 23
·3427-3440
·
IF 5.582
Qun Jia,Zhi-Chao Yan,Yanan Li,Junfeng Liu,Yuansheng Ding,Yujian Liu,Jian Li,Yougen Chen
A series of well-defined di- and triblock acrylic copolymers consisting of hard poly(dicyclopentanyl acrylate) (PdcPA) and soft poly(alkyl acrylate) (PAA) blocks are synthesized by the N-(trimethylsilyl)bis(trifluoromethanesulfonyl)imide (Me3SiNTf2) catalyzed group transfer polymerization (GTP) of dicyclopentanyl acrylate (dcPA) and alkyl acrylate (AA) including n-butyl acrylate (nBA), n-octylacrylate (nOA), 2-ethylhexyl acrylate (EHA), and n-dodecyl acrylate (nDA). The distribution of the monomeric units of the copolymers is controlled through the addition sequence of the comonomers and by the used initiator. In greater detail, the mixed addition of AA and dcPA using the monofunctional 1-methoxy-1-triisopropylsiloxy-2-methylpropene (MTSiPr) as the initiator produces the statistical poly[(alkyl acrylate)-stat-(dicyclopentanyl acrylate)] (Poly(AA-stat-dcPA)), the sequential addition of AA and then dcPA using MTSiPr as an initiator produces the AB-type hard–soft diblock poly(alkyl acrylate)-block-poly(dicyclopentanyl acrylate) (PAA-b-PdcPA), the sequential addition of AA and then dcPA using the bifunctional 1,2-bis[2-methyl-1-(triisopropylsiloxy)prop-1-enyloxy]ethane (MTSiPr2) as the initiator affords the ABA-type hard–soft–hard triblock poly(dicyclopentanyl acrylate)-block-poly(alkyl acrylate)-block-poly(dicyclopentanyl acrylate) (PdcPA-b-PAA-b-PdcPA), and the reverse addition of the two monomers using MTSiPr2 affords the soft–hard–soft BAB-type triblock poly(alkyl acrylate)-block-poly(dicyclopentanyl acrylate)-block-poly(alkyl acrylate) (PAA-b-PdcPA-b-PAA). The formation of the statistical and block copolymers has been confirmed by 1H NMR spectroscopy and size exclusion chromatography (SEC) measurements. Afterwards, the glass transition behavior of the resulting copolymers is analyzed by both differential scanning calorimetry (DSC) and rheometry. A detailed discussion of this part is presented in the following sections.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2025
·Vol. 17
·期 5
·636
·
IF 4.9
Jinbao Ma,Chi Ma,Risheng Long,Yan Jiang,Xingjia Wang,Chang Liu,Fan Li,Lee Tin Sin
Damping material performance influences the efficacy of vibration and noise reduction. However, traditional damping materials often have low damping peaks or narrow damping temperature ranges. In this study, a series of polyurethane (PU)/poly(ethylene methacrylate) (PEMA) composites were synthesised, in which the PU hard segments were varied using toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), and hexamethylene diisocyanate. The soft segments comprised tetrahydrofuran homopolymer glycol. The influence of the hard-segment structure on the properties of the PU/PEMA composites was investigated by infrared spectroscopy, thermogravimetric analysis, dynamic mechanical thermal analysis, and other experimental methods. The performance mechanism was explored from a molecular perspective via integration with molecular dynamics simulations. The PU/PEMA material with IPDI hard segments comprised numerous microphase-separated structures and exhibited greater free volume, fuller molecular-chain movement, and the highest damping performance, with a loss factor of 0.56. The PU/PEMA composites synthesised with TDI and MDI hard segments exhibited better compatibility, with the MDI-PU/PEMA system exhibiting a higher hydrogen-bonding force. This material also exhibited a higher thermal stability, with an initial breakdown temperature of 287.87 °C. This study provides a basis for regulating and optimising the performance of PU-based damping materials.
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）