Journal of Cleaner Production
·
2022
·
IF 11.072
Qin Chen,Zhen Xu,Zongxing Sun,Yanjun Sun,Jixuan Song,Xiao Zhang,Siqi Huan,Long Bai,Jiyou Gu
Petroleum-derived polyurethane using isocyanates by solvent-based processing causes undesired environmental pollution and health effects. Waterborne polyurethane is an alternative to solve this issue, however, they are inefficient as additives and inconvenient for transportation and usage owing to the large amount of water. Herein, water-processable polymethylene polyphenyl polyisocyanate (PAPI, referred as pMDI) powder modified by biobased castor oil is developed. The preparation of pMDI powder is characterized by its appearance, content of –NCO groups, and storage life. The protective mechanism of –NCO groups is explored by a battery of techniques, including microscopies, FTIR, TGA , DSC and reaction kinetics. The optimal formulation for powdered pMDI uses 0.6 wt% SDS prior to de-hydration, which retains a high level of residual –NCO groups up to two-week storage. The formation of polyurea shells covering pMDI powder upon water-processing minimizes contact and interaction between –NCO and moisture in air, blocking consumption of –NCO groups. The pMDI powder can be used as a crosslinking agent for waterborne wood adhesives, showing great bonding performances, particularly improving wet strength (0.84 MPa) at 18 wt% loading level. This strategy offers a simple, green, and cost-effective route to engineer hazardous, high-risk liquid isocyanates into environmentally-friendly, low-risk, and versatile water-processable materials that are suitable as waterborne additives.
研究领域:
材料科学
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环境科学
·
化学工程
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产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2025
·
IF 4.7
Xiaobo Xu,Minghui Cui,Mengqiu Quan,Yuqing Wang,Genzheng Sha,Jin Zhu,Ning Yan,Jing Chen
The use of renewable raw materials to construct environmentally friendly, nontoxic, nonisocyanate polymer materials has been gaining attention. Here, we prepared ferulic acid epoxy (FAE) by directly reacting the lignin derivative ferulic acid with epichlorohydrin. It was used as a precursor to construct five-membered cyclic carbonate (CC) and five-membered cyclic dithiocarbonate (DTC) with CO2 and CS2, respectively. These cyclic carbonates are then cured with different amines to produce nonisocyanate polyurethanes (NIPUs) and nonisocyanate polythiourethanes (NIPTUs) with excellent properties. Ferulic acid contains a rigid aromatic ring structure, so the prepared nonisocyanate polymer materials have excellent mechanical properties, and the maximum tensile strength can reach 34.2 MPa. We compared NIPUs and NIPTUs in terms of their chemical structure, cross-link density, mechanical properties, and processing for remodeling. In addition, Due to the autoxidation of pendant sulfhydryl groups, disulfide bonds are present in the network structure of NIPTUs in addition to thionourethane. This endows NIPTUs with higher cross-link density, lower relaxation activation energy (Ea), and lower remodeling temperature (<140 °C). After thermocompression remodeling, the tensile strength of NIPTUs significantly increased due to the enhanced thermally induced formation of disulfide bonds. This study evaluates the potential for the direct synthesis of biobased aromatic NIPUs and NIPTUs based on ferulic acid, providing a simple route for the preparation of nonisocyanate polyurethanes and polythiourethanes using cyclic carbonates.
研究领域:
材料科学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2016
·
IF 2.567
Junwei Gu,Xutong Yang,Chunmei Li,Kaichang Kou
Bisphenol A cyanate ester/polyglycidyl methyacrylate (BADCy/PGMA) microcapsules were successfully fabricated via a solvent evaporation technique; herein, BADCy is the core material and synthesized PGMA is the shell material. Optimal BADCy/PGMA microcapsules with dense core–shell structures were implanted in the bisphenol A epoxy resin (E-51) matrix to fabricate the corresponding (BADCy/PGMA)/E-51 self-healing composites. Results revealed that the optimal BADCy/PGMA microcapsules presented a spherical shape and rough surface, with mean diameter of 31.5 μm and wall thickness of 2.2 μm. The core material of BADCy maintained its reactivity after being encapsulated by the shell of PGMA. The BADCy/PGMA microcapsules also presented relatively good thermal stability and proper mechanical stability. Moreover, the fabricated (BADCy/PGMA)/E-51 composite with 8 wt % BADCy/PGMA microcapsules possessed relatively good self-healing performance.
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
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
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高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2025
·
IF 5.1
Shumin Jiang,Hangzhou Wang,Jun Shi,Xiaobin Li,Xiaoyan Xiong,Chenguang Kong,Cunzhi Li,Youcheng Huang,Kun Wu,Li Yang
In the semiconductor precision device processing and wafer cutting industry, products are typically etched or sliced to meet specific requirements. During this process, a novel type of adhesive is often utilized for bonding and securing purposes. After processing, some methods, such as light exposure and thermal application, can be used to make the adhesive lose its adhesiveness, so as to facilitate the peeling of the product without damaging the product. In this work, acrylate prepolymers containing photopolymerization groups were synthesized from 4-acryloyloxybenzophenone (4-ABP) and other acrylic monomers. UV-induced tack-loss of the acrylate pressure-sensitive adhesive (PSA) was achieved by blending the acrylic prepolymer with a small molecule isocyanate compound in an appropriate ratio and then coating for heat curing. It was observed that the incorporation of multifunctional isocyanate small molecule groups can enhance the overall performance of the tape. An addition amount of 0.6 wt% hexamethylene diisocyanate (HDI) was found to be more suitable than isophorone diisocyanate (IPDI), as it maintained good bonding performance and resulted in less residual glue. The increase in 4-ABP initially led to an improvement in bonding performance of the pressure sensitive adhesive tape, followed by a decrease, with an optimal addition amount of 1.2 wt%. After UV curing, the 180° peel strength of the adhesive tape measured below 1.0 N/25 mm, exhibiting the most significant decrease in peel strength and minimal residual adhesive content. This characteristic categorized it as a UV-induced tack-loss easy peeling pressure-sensitive adhesive tape. These results contribute to the further research and development of UV-induced tack-loss PSA.
研究领域:
材料科学
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聚合物化学
·
胶粘剂技术
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半导体制造
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光聚合
✓ 已验证
产品关联
DOI
高影响因子
Coatings
·
2022
·Vol. 12
·期 2
·166
·
IF 3.236
Guifeng Xiang,Jing Tu,Heng Xu,Jie Ji,Li Liang,Haozhe Li,Haoran Chen,Jingqing Tian,Xiaode Guo
In this study, we successfully manufactured polyurethane microcapsules containing isocyanate prepolymer as a core material for self-healing protection coatings via interfacial polymerization of a commercial polyurethane curing agent (Bayer L-75) and 1,4-butanediol (BDO) as a chain extender in an emulsion solution. With an optical microscope (OM) and a scanning electron microscope (SEM), the resulting microcapsules showed a spherical shape and an ideal structure with a smooth surface. Fourier transform infrared spectra (FTIR) showed that the core material was successfully encapsulated. Thermal gravimetric analysis (TGA) showed that the initial evaporation temperature of the microcapsules was 270 °C. In addition, we examined the influence of the concentration of the emulsifier and chain extender on the structure and morphology of the microcapsules. The results indicate that the optimal parameters of the microcapsule are an emulsifier concentration of 7.5% and a chain extender concentration of 15.38%. Microcapsules were added to the epoxy resin coating to verify the coating’s self-healing performance by a surface scratch test, and the results showed that the cracks could heal in 24 h. Furthermore, the self-healing coating had excellent corrosion resistance.Keywords:microcapsules;isocyanate prepolymer;coating;self-healing
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 APPLIED POLYMER SCIENCE
·
2024
·Vol. 141
·期 31
·e55723
·
IF 2.7
Xiaoxuan Li,Zheng Yin,Yanru Zhao,Penghui Li,Shengli Wu
Isocyanate-based monomers and polymers have found widespread industrial application; however, the realization of green water-based products via the preparation of stable isocyanate aqueous emulsions remains challenging. Herein, a series of organosilicon and organofluorine synergistically modified amphiphilic branched polyurethanes (HBWPU), synthesized by grafting perfluorohexyl ethanol semi-terminated isophorone diisocyanate (IPDI) onto a hydrophilic polyurethane prepolymer, is presented. Subsequently, using a physical mixing method, stable diisocyanate emulsions are fabricated by preparing diisocyanate latex particles with IPDI as the core and hyperbranched water-based polyurethanes (HBWPU) as the shell. Structural investigations showed that the branching degree and fluorine content of the HBWPU significantly affects the stability of the diisocyanate emulsions. Increasing the degree of branching from 0.34 to 0.86 causes the amount of residual isocyanate ( NCO) groups to decrease from 20.1% to 16.7%. In contrast, an increase in the fluorine content from 0% to 17.8% increases the amount of residual NCO groups from 11.5% to 24.6%. Thus, HBWPU can be used as an emulsifier to prepare waterborne diisocyanate cross-linking agents. Such polyurethane-coated isocyanate aqueous emulsions can increase the hardness and significantly improve the acetone resistance of hydroxyl polyacrylate resins.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2020
·
IF 5.162
De-Fa Hou,Zheng-Ying Liu,Ling Zhou,Huang Tan,Wei Yang,Ming-Bo Yang
Cellulose is an abundant feedstock with renewability and biodegradability . However, it is still challenging to manufacture natural cellulose products by environmentally friendly thermoplastic processing methods. Herein, we proposed a green approach for the heterogeneous preparation of thermoplastic cellulose grafted polyurethane (RCP-g-PU) from amorphous regenerated cellulose paste (RCP) via hydroxyl/isocyanate chemistry. First, amorphous RCP was fabricated through dissolving cellulose in sodium hydroxide aqueous solution and regenerating in polyethylene glycol, resulting in the enhancement of the accessibility of hydroxy groups in cellulose chains. Subsequently, a series of thermoplastic RCP-g-PU with the melt flow temperatures ranging from 160 °C to 226 °C were feasibly synthesized by adding hexamethylene diisocyanate into RCP without using other organic solvents . Eventually, the resultant RCP-g-PU can be directly hot-pressed into transparent films with flexibility and foldability. The reported methodology represents a sustainable route to achieve thermoplastic cellulose derivatives .
研究领域:
材料科学
·
绿色化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Coatings
·
2024
·Vol. 14
·期 4
·410
·
IF 2.9
Huaixuan Mu,Yiqing Deng,Wangcai Zou,Xiandi Yang,Qiang Zhao
Dual microcapsule systems, especially those based on the polyurea matrix, have emerged as pivotal components driving innovation in self-healing materials, thanks to the intrinsic properties of polyurea, primarily diamine and diisocyanate, rendering it an optimal choice for enhancing self-healing coatings. However, the encapsulation of polyurea components is fraught with substantial technical hurdles. Addressing these challenges, a novel methodology has been devised, leveraging n-heptane as a solvent in the liquid diamine emulsion process to facilitate the synthesis of diamine microcapsules. These microcapsules exhibit a uniform spherical morphology and a robust shell structure, with an encapsulated core material ratio reaching 39.69%. Analogously, the encapsulation process for diisocyanate has been refined, achieving a core material percentage of 10.05 wt. %. The integration of this bifunctional microcapsule system into diverse polymeric matrices, including epoxy resins and polyurethanes, has been demonstrated to significantly enhance the self-healing efficacy of the resultant coatings. Empirical validation through a series of tests, encompassing scratch, abrasion, and saltwater immersion assays, has revealed self-healing efficiencies of 21.8% and 33.3%, respectively. These results indicate significant improvements in the durability and self-repair capability of coatings, marking a notable advancement in self-healing materials with promising potential for tailored applications in automotive, aerospace, and construction industries.
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
Polymers
·
2024
·Vol. 16
·期 21
·3045
·
IF 4.7
Hairui Wang,Lan Cao,Xiaolei Wang,Xiurui Lang,Wenwen Cong,Long Han,Hongyu Zhang,Huibin Zhou,Jujie Sun,Chengzhong Zong
Polyurethane (PU) plays a critical role in elastomers, adhesives, and self-healing materials. We selected the most commonly used aromatic isocyanates, 4,4′-methylene diphenyl diisocyanate (MDI) and tolylene-2,4-diisocyanate (TDI), and the most commonly used aliphatic isocyanates, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and dicyclohexylmethane-4,4′-diisocyanate (HMDI), as raw materials, combined with polytetramethylene ether glycol (PTMG) and 1,4-butanediol (BDO) to successfully synthesize five PU materials. The effects of isocyanate structure on polymerization rate, hydrogen bonding, thermal properties, phase separation, wettability, self-healing performance, adhesion, and mechanical properties were systematically investigated. The results show that isocyanates with higher symmetry facilitate hydrogen bonding, but excessive flexibility and crystallinity may inhibit its formation. MDI-based PU exhibits the highest hydrogen bonding index (HBI) of 4.10, along with the most distinct phase separation and the highest tensile strength of 23.4 MPa. HMDI-based PU demonstrates the best adhesion properties, with the highest lap shear strength of 7.9 MPa, and also exhibits excellent scratch healing ability. IPDI-based PU shows good self-healing performance, recovering 88.7% of its original tensile strength and 90.6% of its original lap shear strength after heating at 80 °C for 24 h. Furthermore, all the samples can be reprocessed by melt or solution methods, showing excellent recyclability.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2019
·Vol. 11
·期 6
·950
·
IF 3.164
Hongtao Cao,Beijun Liu,Yiwen Ye,Yunfang Liu,Peng Li
Bisphenol A dicyanate (BADCy) resin microparticles were prepared by precipitation polymerization synthesis and were homogeneously dispersed in a BADCy prepolymer matrix to prepare a BADCy self-reinforced composites. The active functional groups of the BADCy resin microparticles were characterized by Fourier transform infrared (FT-IR) spectroscopy. The results of an FT-IR curve showed that the BADCy resin microparticles had a triazine ring functional group and also had an active reactive group -OCN, which can initiate a reaction with the matrix. The structure of the BADCy resin microparticles was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). From the TEM results, the BADCy resin microparticles dispersed in the solvent were nano-sized and distributed at 40–60 nm. However, from the SEM results, agglomeration occurred after drying, the BADCy resin particels were micron-sized and distributed between 0.3 μm and 0.6 μm. The BADCy resin prepolymer was synthesized in our laboratory. A BADCy self-reinforced composite was prepared by using BADCy resin microparticles as a reinforcement phase. This corresponds to a composite in which the matrix and reinforcement phase are made from different morphologies of the same monomer. The DSC curve showed that the heat flow of the microparticles is different from the matrix during the curing reaction, this means the cured materials should be a microscopic two-phase structure. The added BADCy resin microparticles as reaction sites induced the formation of a more complete and regular cured polymer structure, optimizing the cross-linked network as well as increasing the interplay between the BADCy resin microparticles and prepolymer matrix. Relative to the neat BADCy resin material, the tensile strength, flexural strength, compressive strength and impact strength increased by 98.1%, 40.2%, 27.4%, and 85.4%, respectively. A particle toughening mechanism can be used to explain the improvement of toughness. The reduction in the dielectric constant showed that the cross-linked network of the self-reinforced composite was more symmetrical and less polar than the neat resin material, which supports the enhanced mechanical properties of the self-reinforced composite. In addition, the thermal behavior of the self-reinforced composite was characterized by thermogravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMTA). The results of DMTA also establishes a basis for enhancing mechanical properties of the self-reinforced composite.Keywords:cyanate ester;self-reinforced composite;cross-linked network;mechanical property
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 137
·期 45
·49395
·
IF 2.52
Jianguang Huang,Peng Li,Weihong Hu,Ruikui Du,Guizhe Zhao,Zhi Wang
The toughness of polycyanate ester is improved by adding epoxy pre-polymer with varying molecular weights. The curing mechanism of epoxy prepolymer (PreEP) and cyanate ester (CE) is discussed based on differential scanning calorimeters and Fourier-transform infrared spectroscopy. The mechanical, phase separated structures and thermal properties of PreEP/CE are also evaluated. It is found that the molecular weight of PreEP can reach 1,800 when it is cured at 90°C for 45 min by using a set amount of polyetheramine. Meanwhile, by increasing the molecular weight of the prepolymer, the mechanical properties of PreEP/CE show increased first, and then decreased. 0.2 PreEP/CE has the highest bending strength and impact strength (105.8 MPa and 18.3 kJ·m −2 ). There are 26.7 and 114.5% higher than those of polycyanate ester, respectively. The tougher PreEP/CE is attributable to the phase-separated structures and the decrease in the cross-linked product (Oxazolidinone) in PreEP and CE. The method showed in this article provides a new way to improve the toughness properties of thermoset resin.
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）