新型聚芳醚腈固化邻苯二甲腈树脂的研究

通过两步一锅法制备了氨基封端的新型杂萘联苯聚芳醚腈（A-PPEN）,其具有比常用的芳香二胺固化剂4,4′-二氨基二苯砜（DDS）更为优异的热稳定性。采用差示扫描量热法（DSC）研究了A-PPEN对间苯二酚基邻苯二甲腈树脂前体（DPPH）的固化过程,结果显示该固化体系具有自催化固化的特征,A-PPEN的投料比会影响体系的固化活性。另外研究了该固化体系的流变特性和热稳定性,结果表明树脂的5%热失重温度（T_d5%）最高可达552.9℃,800℃时残炭率（C_y800）为78.6%,最低黏度可至0.06 Pa·s,具有优异的热稳定性和较宽的加工温度窗口。     

环氧化山桐子油的制备及其对双酚A型环氧树脂增韧改性研究

双酚A型环氧树脂（DGEBA）面临的主要问题是韧性较差。为了有效解决该问题,以山桐子油为原料制备环氧化山桐子油（EPIO）,以EPIO为增韧改性剂对DGEBA进行增韧改性,制备改性双酚A型环氧树脂（DGEBA/EPIO）,分别以甲基六氢苯酐（MHHPA）或聚醚胺D-400为固化剂对改性环氧树脂进行固化。采用傅里叶变换红外光谱（FTIR）、热重分析仪（TG）、动态机械性能分析仪（DMA）、万能力学试验机、全自动接触角仪和扫描电子显微镜（SEM）,对改性环氧树脂固化物的热学性能和力学性能进行表征。结果表明：EPIO可以明显提高双酚A型环氧树脂的韧性。当EPIO用量为DGEBA用量的5%,MHHPA固化后的DGEBA/EPIO的断裂伸长率可由纯树脂的2.73%提升至13.15%。添加EPIO也可以有效提升DGEBA的耐热性和疏水性。     

腰果酚基缩水甘油醚的制备及其性能研究

以腰果酚、环氧氯丙烷为主要原料,制备腰果酚基缩水甘油醚(CGE),并研究CGE/双酚A型环氧树脂(DGEBA)固化物的性能。研究表明,在CGE用量达15%时,环氧树脂固化物的机械性能达到最大值。与纯DGEBA的性能相比,复合材料的拉伸强度、弯曲强度、冲击强度分别提高了35.4%,43.3%和109.5%。随着CGE含量的增加,材料的玻璃化转变温度降低。固化微观相分离和断面出现"海岛"结构是腰果酚基缩水甘油醚的增韧机理。     

腰果酚基缩水甘油醚的制备及其性能研究

以腰果酚、环氧氯丙烷为主要原料,制备腰果酚基缩水甘油醚(CGE),并研究CGE/双酚A型环氧树脂(DGEBA)固化物的性能。研究表明,在CGE用量达15%时,环氧树脂固化物的机械性能达到最大值。与纯DGEBA的性能相比,复合材料的拉伸强度、弯曲强度、冲击强度分别提高了35.4%,43.3%和109.5%。随着CGE含量的增加,材料的玻璃化转变温度降低。固化微观相分离和断面出现"海岛"结构是腰果酚基缩水甘油醚的增韧机理。     

糠醇缩水甘油醚稀释的环氧体系的性能研究

通过力学性能和热性能测试研究了糠醇缩水甘油醚(FGE)稀释的双酚A环氧树脂(DGEBA)体系的固化性能和固化反应动力学。通过Málek自催化机理模型求得添加10%FGE的DGEBA与脂肪族聚酰胺固化剂的固化反应平均活化能为64.66kJ/mol,低于苄基缩水甘油醚(BGE)稀释体系。以FGE稀释的固化产物的拉伸强度达到62.93MPa,比BGE体系高出20%左右。拉伸伸长率达4.66%,是BGE体系的4倍左右。添加FGE的固化物冲击强度达36.17MPa,比BGE体系高出约70%左右。使用FGE和BGE的环氧固化物的玻璃化转变温度分别为46.32℃和52.36℃。FGE和BGE体系固化物的5%的热失重温度分别为260.79℃和194.59℃。FGE是1种良好的环氧树脂稀释剂。     

高生物基含量光固化涂料的制备及其性能研究

环氧化大豆油丙烯酸酯(AESO)已大规模用于UV固化涂料中,但目前同时获得高生物基含量以及优异机械性能的大豆油基光固化涂料依然是一个很大的挑战。文中设计并合成了异山梨醇甲基丙烯酸酯(ISDMA)作为光固化活性稀释剂。使用流变仪研究了ISDMA对AESO稀释性的影响。将ISDMA与AESO混合制备了一系列生物基UV固化涂料,并对这些涂料的热机械性能、力学性能和涂层基本性能进行了评估。结果表明:ISDMA对AESO表现出良好稀释性的同时,可以有效地提高固化涂层的玻璃化转变温度(T_g)、储能模量和硬度。     

CTBN/PI复合改性环氧树脂的结构与性能

采用端羧基丁腈橡胶（CTBN）和聚酰亚胺树脂（PI）为改性剂,甲基六氢苯酐（MeHHPA）为固化剂,2,4,6-三（二甲氨基甲基）苯酚（DMP-30）为固化促进剂,对双酚A型环氧树脂（DGEBA)进行改性,研究了CTBN/PI复合改性剂对DGEBA力学性能、动态热力学性能和形态结构的影响。结果表明,CTBN/PI复合改性剂在保持弹性模量损失很小的情况下,显著提高了DGEBA的冲击强度、断裂强度和断裂伸长率;当复合改性体系中CTBN和PI添加量分别为20~30份、1.5~2.0份（质量份,下同）时,体系的综合力学性能最佳;适当引入PI增加了体系储能模量和耐热性,DGEBA的冲击断面发生了塑性变形,韧性得到了改善。     

N⁃乙基哌嗪基邻苯二甲单酰胺酸锌对PVC热稳定性能的影响

以邻苯二甲酸酐、N?乙基哌嗪为原料合成N?乙基哌嗪基邻苯二甲单酰胺酸,再将其与氯化锌反应制备了N?乙基哌嗪基邻苯二甲单酰胺酸锌（ZNEP）,然后将ZNEP分别与季戊四醇、二苯甲酰甲烷（β?二酮）、环氧大豆油和亚磷酸一苯二异辛酯进行复配得到4种复合热稳定剂;采用刚果红试纸法、热老化烘箱法,转矩流变仪法和热重分析仪（TG）研究了不同复合热稳定剂对聚氯乙烯（PVC）静态和动态热稳定性能及热降解过程的影响。结果表明,当ZNEP、季戊四醇复配质量比为1∶2时,PVC样品的热稳定性最好,其静态热稳定时间和动态热稳定时间分别为2 340 s和1 602 s;同时,与不添加热稳定剂的样品相比,其质量损失率为5 %、10 %及质量损失速率最快时对应的温度（T_{5 %}、T_{10 %}、T_max）均表现出了较大程度的提升,说明该复合热稳定剂能有效抑制PVC的热降解。     

桐油制备C_(21)聚酰胺环氧固化剂的性能及固化反应动力学研究

以桐油的甲醇酯交换产物桐酸甲酯和丙烯酸为原料,通过Diels-Alder加成反应合成了C21二元酸单甲酯(TMAA),桐酸甲酯和丙烯酸的加成温度为180℃,反应时间3 h,比通用C21二元酸的合成反应温度低70℃。然后用C21二元酸单甲酯和不同多元胺酰胺化制备了3种不同胺值的C21二酸聚酰胺环氧固化剂。机械性能测试显示,C21二元酸聚酰胺和双酚A环氧树脂(DGEBA)的环氧固化物和C36二聚酸聚酰胺650C的DGEBA固化物相比,具有更高的机械强度和模量。胺值为496 mg/g的C21二元酸聚酰胺与DGEBA的固化产物拉伸强度达58.63 MPa,断裂伸长率为3.27%,弹性模量达2 635.84 MPa,弯曲强度达99.9 MPa。差示扫描热分析法(DSC)测得C21二元酸聚酰胺的DGEBA固化物的玻璃化温度分别为108、109和116℃,比C36二聚酸聚酰胺的DGEBA固化物的玻璃化温度高出50℃左右。n级反应机理求取的3种固化剂与DGEBA的固化反应活化能分别为62.179、56.551和59.761 kJ/mol,比C36二聚酸聚酰胺与DGEBA的固化反应活化能高出约10 kJ/mol。固化反应动力学得出固化剂与DGEBA的凝胶温度、固化温度和后固化温度分别为40、90和150℃左右。     

一种基于氢氧化镁的环氧树脂固化剂的制备与表征

通过己二酸(AA)和二乙烯三胺(DETA)改性制得了一种氨基功能化氢氧化镁(DETA-AA-MH),并将其用作环氧树脂固化剂。采用FTIR、XRD、固体核磁、纳米粒径分析仪、SEM和TGA对DETA-AA-MH的化学结构、形貌以及热稳定性进行了表征,并通过FTIR和DSC分析得到环氧树脂(DGEBA)和DETA-AA-MH发生固化反应的最佳质量分数分别为84.03%和15.97%,热固化实验分析得到最佳反应条件为:预固化温度及时间(80℃/0.5 h)和后固化温度及时间(110℃/3 h)。LOI测试分析结果表明,DGEBA/DETA-AA-MH较DGEBA/DETA的LOI提高了10.15%。采用SEM和EDS对环氧树脂燃烧后的炭残留物进行分析,结果表明,在燃烧过程中DETA-AA-MH促进保护碳层的形成。机械性能测试表明,DGEBA/DETA-AA-MH(固化剂质量分数15.97%)与DGEBA/DETA(固化剂质量分数7.38%)对比发现其弯曲强度、弯曲模量和冲击强度分别提高了663.64%、49.92%、235.77%。     

Low-temperature fast curable behavior and properties of bio-based carbon fiber composites based on resveratrol

Environmentally friendly materials are an integral part of sustainable chemistry, and bio-based polymer composites are an important class of materials. The manufacture of composites is expected to reduce or even eliminate the use of adjuvants, considering the importance of reducing energy consumption and avoiding health and environmental risks. In this study, a phenyl-containing, polyfunctional, bio-based epoxy resin (TGER) was synthesized, and carbon fiber-reinforced, bio-based epoxy resin composites were fabricated by vacuum-assisted resin infusion using two aromatic amine curing agents, 4,4′-diaminodiphenylmethane (DDM) and 3,3′-diethyl-4,4′-diaminodiphenylmethane (DEDDM). Curing reactions and rheological behavior studies showed that TGER had higher curing reactivity toward DDM and DEDDM than to diglycidyl ether of bisphenol A (DGEBA) and possessed good processability. The results indicated that the resveratrol-based epoxy resin displayed low-temperature fast curing properties. The evaluation of the mechanical properties of the carbon fiber composites showed that the flexural strengths of CF/TGER/DDM and CF/TGER/DEDDM were 520 and 628 MPa, respectively. The initial decomposition temperature of CF/TGER composites is above 200°C. Furthermore, the carbon fiber–reinforced biopolymers possess excellent heat resistance. Therefore, carbon fiber-reinforced, resveratrol-based epoxy resin composites are promising candidates as alternatives to petroleum-based high-performance carbon fiber composites.     

Synthesis of a Sustainable and Bisphenol A-Free Epoxy Resin Based on Sorbic Acid and Characterization of the Cured Thermoset

In the present study, an epoxy compound, 1,2-epoxy-6-methyl-triglycidyl-3,4,5-cyclohexanetricarboxylate (EGCHC) synthesized from sorbic acid, maleic anhydride, and allyl alcohol is proposed. Using commodity chemicals, a bio-based carbon content of 68.4 % for the EGCHC resin is achieved. When cured with amine hardeners, the high oxirane content of EGCHC forms stiff cross-linked networks with strong mechanical and thermal properties. The characterization of the epoxy specimens showed that EGCHC can compete with conventional epoxy resins such as DGEBA. A maximum stiffness of 3965 MPa, tensile strength of 76 MPa, and T_g of 130 °C can be obtained by curing EGCHC with isophorone diamine (IPD). The cured resin showed to be decomposable under mild conditions due to the ester bonds. The solid material properties of EGCHC expose its potential as a promising bisphenol A, and epichlorohydrine free alternative to conventional petroleum-based epoxies with an overall high bio-based carbon content.     

丙烯酸改性松香基环氧树脂固化反应与性能研究

将丙烯酸改性松香基环氧树脂 (ARER)与甲基六氢苯酐 (MeHHPA)进行固化反应研究。以示差扫描量热法 (DSC)对其固化过程进行跟踪分析 ,计算出固化反应的表观活化能为 98 11kJ/mol,固化反应级数为 0 89。通过对固化剂用量对化学反应程度影响的研究得知 ,当m(ARER)∶m(MeHHPA)为 10∶5 2时固化反应完全。通过红外光谱分析 ,表征了固化反应行为及完成固化行为的条件 ,同时还测定了固化体系的凝胶时间及固化产物的耐热性。比较了ARER及 6 18环氧与MeHHPA固化体系的力学性能 ,结果表明两者力学性能相似。     

A Study of the Interphase Region in Carbon Fibre/Epoxy Composites using Dynamic Mechanical Thermal Analysis

We have examined the effect of fibre addition on the glass transition temperature (T_g) of two epoxy resin systems (an amine cured and an anhydride cured epoxy system) using dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC). The presence of fibres changes the glass transition temperature (T_g) of an anhydride cured epoxy resin but does not affect that of an amine cured epoxy. The data suggest that two counteracting mechanisms are responsible for these changes: firstly, the presence of fibres causes a restriction of the molecular motion in the resin system, and secondly, the presence of carboxyi and keto-enol groups on the fibre surface inhibit curing of the resin close to the fibre, i.e. in the interphase region. The former increases the T_g and is a long range effect whereas the latter decreases the T_g and is a localised phenomenon. Changes in the dynamic properties of the interphase region are only detected when the samples are loaded in the longitudinal direction and not in the transverse direction where bulk matrix properties dominate. Sizing the fibres before their incorporation into the epoxy resin eliminates the variation in interfacial properties arising from differences in fibre surface chemistry.     

Preparation and Application of a New Curing Agent for Epoxy Resin

A new curing agent based on palmitoleic acid methyl ester modified amine (PAMEA) for epoxy resin was synthesized and characterized. Diglycidyl ether of bisphenol A (DGEBA) epoxy resins cured with different content of PAMEA along with diethylenetriamine (DETA) were prepared. The mechanical properties, dynamic mechanical properties, thermal properties, and morphology were investigated. The results indicated that the PAMEA curing agent can improve the impact strength of the cured epoxy resins considerably in comparison with the DETA curing agent, while the modulus and strength of the cured resin can also be improved slightly. When the PAMEA/epoxy resin weight ratio is 30/100, the comprehensive mechanical properties of the cured epoxy resin are optimal; at the same time, the crosslinking density and glass transition temperature of the cured epoxy resin are maximal.     

Versatile bio-based epoxy resin: From banana waste to applied materials

Bio-based epoxy resin is a promising candidate for petroleum-based resins due to its abundant reserves and low-cost products, which mainly use polyphenolic composites as precursors. Liquefied banana pseudo stem (LBPS), a highly active compound obtained by liquefaction with 7.5% of sulfuric acid as catalyst at 160°C, was used to synthesize bio-based epoxy resin. FTIR and SEM demonstrated the synthetic process of LBPS-based epoxy resin (LBPSER) from waste banana pseudo stem (BPS). Mechanical test, reagent resistance, dynamic mechanical analysis, and thermogravimetric analysis were utilized to evaluate the mechanical and chemical properties of LBPSER. With polyamide (PA) as hardener, LBPSER-PA adhesive exhibited an optimum shear strength that is comparable with that of commercial diglycidyl ether of bisphenol A (DGEBA), corresponding to 11.86 vs 11.89 MPa. Interestingly, the shear strength of this adhesive curing at 40°C could get 9.52 MPa for wood materials. The adhesive also performed excellent resistance to organic agents, adverse acidic, and alkaline environments. Notably, as the content of LBPSER in adhesive increased, an increase of glass transition temperature could be verified from 42 to 100°C. The LBPSER-PA adhesive presented good thermal and physicochemical performances, thereby suggesting the potential of utilizing liquefied product from BPS as alternative to toxic bisphenol A in synthesizing bio-based epoxy resin. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47135.     

Mechanical and Morphological Behavior of Bismaleimide-Modified Soy-Based Epoxy Matrices

This study is concerned with the preparation and mechanical characterization of bio-based polymers from renewable resources. Epoxidized soybean oil at various concentrations is cured with an amine curing agent. The prepared matrices have been chemically modified with three types of bismaleimides, namely N, N′-bismaleimido-4, 4′-diphenyl methane (BMI-1), 1,3-bis(maleimido)benzene(BMI-2) and 3,3′-bis(maleimido phenyl)phenyl phosphineoxide (BMI-3). The crosslinked matrices thus developed were characterized for their mechanical properties such as tensile strength, tensile modulus, flexural strength, flexural modulus, and impact strength. The incorporation of bismaleimides in the soy-based matrices significantly enhances the mechanical properties. The morphological behavior of matrices is also studied using a scanning electron microscope. The results indicate that the bismaleimide-modified soy-based epoxy resin at appropriate concentration holds great potential as a replacement for petroleum-based materials in engineering applications.