PPENK增韧改性BMI树脂体系的制备与性能

采用溶液法制备了杂萘联苯聚芳醚腈酮(PPENK)/双马来酰亚胺树脂(BMI)共混体系。通过差示扫描量热法(DSC)对共混体系固化反应动力学进行了研究,固化活化能为85.8 kJ/m2。采用冲击和拉伸实验考察了PPENK含量对共混体系力学性能的影响,共混体系的冲击强度为1.83 kJ/m2～2.95 kJ/m2,拉伸强度为68 MPa～84 MPa,拉伸模量为1.14 GPa～1.53 GPa。通过对固化物断面的扫描电镜(SEM)分析了增韧机理,改性后的BMI树脂在断裂时发生了塑性变形。通过热重分析法(TGA)研究了体系的耐热性,共混体系在氮气气氛中5%热失重温度为420℃～426℃。     

不同长度脂肪链含萘环结构环氧树脂对NC-3000型环氧树脂的改性研究

为了研究不同脂肪链长度的环氧树脂对联苯苯酚环氧树脂/苯酚-亚联苯基固化剂(NC-3000/GPH-65)环氧体系的影响,合成了两种含萘环结构的具有不同长度脂肪链的环氧树脂R1和R2,通过核磁共振氢谱(1 HNMR)和元素分析(EA)对其结构进行了表征。将R1和R2以1%、3%、5%、7%(质量分数)的添加量分别加入NC-3000/GPH-65固化体系中制备固化物。通过示差扫描量热(DSC)和凝胶化时间测试研究R1和R2对NC-3000/GPH-65固化体系固化行为的影响,对改性固化物进行了热重分析(TGA)、弯曲强度测试、拉伸强度测试、吸水性和玻璃化转变温度(Tg)测试。结果表明,具有长链结构的R1对固化反应有延缓作用,而R2对固化反应有促进作用。随着R1和R2添加量的增加,改性固化物的力学性能、耐水性、Tg和耐热性都得到了一定程度的提高,通过SEM对固化物断面进行分析发现,固化物的断裂形式由脆性断裂变成韧性断裂。与短链结构的R2相比,长链结构的R1能够使固化物的力学性能、Tg和吸水率得到更大程度的提升,而其耐热性有一定程度的降低。     

PP/纳米SiO2/氮磷阻燃剂复合材料的研究

目的研究聚丙烯复合材料的燃烧行为和纳米SiO_2含量对复合材料力学性能的影响。方法采用熔融共混方法,将聚丙烯、氮磷复配阻燃剂及表面改性的纳米SiO_2制备成聚丙烯复合材料。结果在燃烧过程中纳米SiO_2对阻燃性能有一定影响,氮磷复配阻燃剂是影响复合材料阻燃性能的关键因素。随着纳米SiO_2含量的增加,复合材料的极限氧指数先增加后降低,当纳米SiO_2质量分数为1%时,复合材料的极限氧指数最大。随着纳米SiO_2含量的增加,复合材料的拉伸、冲击、弯曲强度和弯曲模量呈现先增大后减小的现象。结论氮磷复配阻燃剂与纳米SiO_2对于复合材料有一定的协同阻燃效果。当纳米SiO_2质量分数为1%时,复合材料的阻燃及力学性能最优。     

洋麻/棉混纺织物增强环氧树脂复合材料的性能研究

对以环氧树脂为基体,不同混纺比的洋麻/棉混纺织物为增强体所制备的复合材料进行力学性能测试,从而优选最佳洋麻/棉混纺比。然后对最佳混纺比的洋麻/棉混纺织物进行阻燃处理,并测试其增强环氧树脂复合材料力学性能。结果表明,洋麻/棉(40/60)混纺织物增强环氧树脂复合材料力学性能最优,其拉伸强度和模量分别为101.9MPa和6.16GPa;弯曲强度和模量分别为189.64MPa和12.14GPa;剪切强度为17.47MPa。经过阻燃处理的洋麻/棉(40/60)混纺织物增强环氧树脂复合材料其拉伸强度和模量分别为67.85 MPa和5.81GPa;弯曲强度和模量分别为126.02 MPa和8.96GPa;剪切强度为13.62MPa;阻燃性能为自息时间0s,损毁长度4cm;其性能满足汽车零件性能要求,具有一定的实际应用性。     

一种含硅阻燃剂的合成及在PC中的应用

通过苯酚改性含氢硅油合成出一种新型聚碳酸酯用含硅阻燃剂(HSOP)。阻燃及力学性能测试结果表明加入HSOP可以有效地提高聚碳酸酯(PC)的阻燃性,当阻燃剂质量分数5%时,氧指数由纯PC的26.5%提高到32.5%,UL-94阻燃级别由V-2级提高到V-0级,冲击强度和断裂伸长率增加48.9%和37.6%。通过样品的TGA测试和SEM对残炭表面结构分析考察了HSOP对PC的阻燃机理,结果证实,阻燃剂在燃烧时能和PC发生交联反应,导致燃烧后形成致密炭层是材料阻燃性能提高的关键因素。     

低熔点固化剂对环氧树脂性能的影响

研究低熔点固化剂(MOEA)对环氧树脂性能的影响,并和以4,4′-二氨基二苯甲烷(DDM)为固化剂的环氧树脂的性能进行对比。通过流变仪研究固化剂对环氧树脂体系的黏度-温度特性的影响;采用差示扫描量热法(DSC)研究固化剂对环氧树脂固化行为的影响;并通过万能材料试验机、动态热机械分析仪(DMA)和热失重分析仪(TGA)研究环氧树脂固化物的力学性能和热性能。结果表明,以MOEA为固化剂的环氧树脂(MOEA40)比以DDM为固化剂的环氧树脂(DDM30)具有更好的黏度-温度特性,在宽的温度区间(60~140℃)表现出低的黏度(0.2~3.5Pa·s)。固化工艺处理后,MOEA40的固化物表现出了优异的力学性能,其弯曲强度为147MPa,拉伸强度为89MPa,比DDM30的固化物的弯曲强度(134MPa)和拉伸强度(80MPa)分别提高了9.7%和11.2%。此外,MOEA40的固化物还具有高的玻璃化转变温度(168℃)和初始分解温度,在氮气条件下,其失重5%的温度为367℃。     

稀释剂对DDM/E-51环氧树脂体系力学性能的影响

以乙二醇二缩水甘油醚(EGDGE)为活性稀释剂,4,4’-二氨基二苯甲烷(DDM)为固化剂,采用模具浇铸法制备了高力学性能的环氧固化物,详细研究了稀释剂含量对其拉伸、弯曲和冲击强度等力学性能的影响。结果表明,随着稀释剂含量的增加,环氧树脂的拉伸和弯曲强度及模量先增加后减小,添加40%(质量分数,下同)稀释剂时,拉伸和弯曲强度分别达到最大值96.7MPa和168.3MPa,比不添加稀释剂时提高了24.3%和19.2%;拉伸和弯曲模量也分别达到最大值1958.6MPa和3573.9MPa,比不添加稀释剂时提高77.8%和19.8%。添加20%稀释剂时,冲击强度达到最大值37.43kJ/m2,比不添加稀释剂时提高23.1%。     

原位聚合法制备连续玻璃纤维增强PCBT复合材料及其性能

采用环状对苯二甲酸丁二醇酯(CBT)原位聚合制备了连续玻璃纤维(GF)增强聚环状对苯二甲酸丁二醇酯(PCBT)复合材料。考察了聚合反应中催化剂用量对PCBT结晶度以及GF/PCBT复合材料力学性能的影响。当催化剂用量为0.5%(质量分数)时, PCBT的结晶度为53%, GF/PCBT的力学性能达到最佳, 拉伸强度为522 MPa, 拉伸模量为27 GPa, 弯曲强度为481 MPa, 弯曲模量为24.8 GPa, 层间剪切强度(ILSS)为43 MPa。SEM观察表明, 发现催化剂用量为0.5%时, 树脂与纤维的结合性较好。进一步研究了淬火和退火后处理对复合材料力学性能的影响。发现复合材料退火处理后具有较好的力学性能, 其中拉伸强度为545 MPa, 弯曲强度为495 MPa。     

亚麻纤维增强聚乳酸可降解复合材料的制备与性能

将制浆造纸用亚麻短纤维与聚乳酸(PLA)熔融共混,用注塑方法成型亚麻纤维/聚乳酸复合材料试样。通过差示扫描量热实验(DSC)、动态力学性能测试(DMA)、热重分析(TGA)和力学性能测试等方法,研究了聚乳酸和亚麻纤维在不同质量配比下,复合材料热性能、动态力学性能和力学性能的变化规律。随着亚麻纤维的加入,复合材料的结晶度增大,热稳定性增强,储能模量得到提高,力学性能也有了明显变化:纤维含量为20%时,拉伸强度为45.88 MPa,比纯PLA的增加了21%;同时,弯曲模量的增幅达到30%。     

液晶环氧树脂增韧改性E-51树脂体系性能研究

目的研究液晶环氧树脂含量对E-51树脂体系固化性能和力学性能的影响。方法采用动态DSC法,研究了液晶环氧树脂对固化反应性的影响;采用力学性能测试和扫描电镜的方法,研究了液晶环氧树脂对固化物力学性能的影响,及其增韧机理。结果液晶环氧树脂含量越高,树脂体系固化反应越快。液晶环氧树脂的加入使冲击强度、弯曲强度和拉伸强度均得到提高。结论液晶环氧树脂质量分数为7%的配方,冲击强度和弯曲强度最高;质量分数为10%的配方拉伸强度最高。     

耐高温异构聚酰亚胺树脂及其复合材料

采用改性的单体反应物聚合法(MPMR)合成了一系列低黏度、耐高温异构聚酰亚胺树脂, 研究了树脂预聚物分子质量对树脂的高温流变行为、固化后热氧化稳定性的影响, 并对树脂的分子结构及其复合材料的加工工艺性能、力学性能进行了表征。结果表明: 树脂预浸液常温储存期大于两个月, 亚胺化后PI-2纯树脂最低黏度为154 Pa·s, 固化后树脂质量损失5%的温度大于560 ℃; 石英纤维/PI-2树脂基复合材料在室温和500 ℃的弯曲强度分别为917、197 MPa, 弯曲模量分别为29、22 GPa, 拉伸强度分别为760、341 MPa, 拉伸模量分别为32、31 GPa, 压缩强度分别为570、95 MPa, 层间剪切强度分别为62、10 MPa。      

The effect of graphene presence in flame retarded epoxy resin matrix on the mechanical and flammability properties of glass fiber-reinforced composites

The effect of adding graphene in epoxy containing either an additive (MP) or reactive-type (DOPO) flame retardant on the thermal, mechanical and flammability properties of glass fiber-reinforced epoxy composites was investigated using thermal analysis; flexural, impact, tensile tests; cone calorimetry and UL-94 techniques. The addition of MP or DOPO to epoxy had a thermal destabilization effect below 400 °C, but led to higher char yield at higher temperatures. The inclusion of 10 wt% flame retardants slightly decreased the mechanical behavior, which was attributed to the poor interfacial interactions in case of MP or the decreased cross-linking density in case of DOPO flame retarded resin. The additional graphene presence increased flexural and impact properties, but slightly decreased tensile performance. Adding graphene further decreased the PHRR, THR and burning rate due to its good barrier effect. The improved fire retardancy was mainly attributed to the reduced release of the combustible gas products.     

化学处理和吸湿水对剑麻纤维及其与树脂界面性能的影响

使用KMnO₄、NaOH、阻燃剂、硅烷对剑麻纤维进行表面处理。采用单丝拉伸和微脱粘方法分别测试了剑麻纤维的拉伸性能及其与改性丙烯酸酯、环氧树脂的界面性能,考察了吸湿水对剑麻纤维表面形貌、拉伸性能及其与树脂界面粘结的影响,分析了相应的破坏模式。结果表明,经过表面化学处理后剑麻纤维的拉伸强度和模量均有不同程度的下降,其中经KMnO₄和硅烷处理后,纤维拉伸强度下降了44%,经NaOH处理后其拉伸强度降低了27%,阻燃剂处理对剑麻性能的影响不明显。表面化学处理还会降低剑麻纤维与改性丙烯酸酯的界面粘结强度,其下降的幅度与纤维拉伸强度下降程度不一致,阻燃剂处理的剑麻/改性丙烯酸酯的界面强度最低,仅为2.0 MPa,较未处理剑麻纤维复合体系下降了80%。经硅烷处理后,剑麻纤维的吸水率下降,吸水后其拉伸性能保留率高于未处理剑麻纤维。湿态条件下未处理剑麻纤维与环氧树脂的界面强度为6.6 MPa,高于硅烷处理剑麻/环氧树脂的界面强度,其断口形貌表明硅烷处理可导致微纤之间的弱粘结,从而降低了剑麻纤维自身及其与树脂的界面性能。     

Effects of diammonium phosphate on the flammability and mechanical properties of bio-composites

The flammability, thermal stability and mechanical properties of natural fiber-reinforced thermoplastic bio-composites were measured using a horizontal burning test, thermogravimetric analyzer, and universal testing machine, respectively. The composites were fabricated from film resins (Polylactic-acid, PLA and Polypropylene, PP) and natural fibers (coconut filter and jute fiber) by a hot press machine. To improve the flame retardancy of the bio-composites, various diammonium phosphates (DAP) were treated into the fibers. In general, the results indicate that increasing the percentage of DAP used to treat the fibers effectively improves the flame resistant, weight loss rate, and flexural modulus but decreases the flexural and tensile strengths of the bio-composites. Bio-composites with DAP-treated fibers showed a greater flexural modulus than those with untreated fibers, and the flexural modulus was even greater than that of neat polymers (PLA and PP). Also, increasing the percentage of DAP for treatment of the fibers in the composites decreases the temperature required for 5% weight loss and the decomposition rate, but increases the char residual at 500 °C. The best linear burning rate and weight loss rate were observed for fiber treatment with 5% DAP. The compressive and wear properties of these bio-composites were also studied.     

无卤固态芳香族磷酸酯阻燃的聚碳酸酯

将无卤固态芳香族磷酸酯(SDP)用于阻燃聚碳酸酯(PC),研究了其对PC阻燃性能、力学性能、热分解行为及灼烧残炭的影响。实验结果表明,SDP对PC有较高的阻燃效率,添加量为6%时,可使PC达UL94V-0级(1.6 mm),LOI近35%。此外,SDP能提高PC的拉伸强度、弯曲强度、拉伸模量、弯曲模量及添加量小于4%的断裂伸长率。热失重-红外联用(TG-IR)数据表明,SDP可提前并加速PC的交联成炭,但不能提高PC的成炭率。     

Organic/inorganic flame retardants containing phosphorus,nitrogen and silicon: Preparation and their performance on the flame retardancy of epoxy resins as a novel intumescent flame retardant system

This paper presents the preparation of novel organic/inorganic flame retardants containing phosphorus, nitrogen and silicon (organic/inorganic FRs). The organic/inorganic FRs were highly water resistant, as suggested by the water contact angle and water solubility tests. The organic/inorganic FRs were then incorporated into epoxy resins (EP) at different phosphorus/nitrogen ratios and the flame retardancy of EP/FRs composites was characterized. The results showed that synergistic effects on the flame retardancy of EP composites existed between the DOPO-VTS and TGIC-KH. The char residues for EP/FRs composites were increased, and the highest char residues were obtained in air atmosphere (3.8 wt.%) when the DOPO-VTS/TGIC-KH is 4/1. The MCC results also showed that the THR of epoxy resins were also decreased when the DOPO-VTS/TGIC-KH is 4/1, which was in accordance with the highest LOI and UL-94 results. The SEM, FTIR, XPS and TG-FTIR results of pyrolysis products in both condensed and gases phases indicated that the strategy of organic/inorganic FRs combined condensed phase and gases phase flame retardant strategies such as the phosphorus–nitrogen synergism systems, the silicon reinforced effects in the condensed phase and DOPO flame retardant systems in the gases phase, resulting in significant improvements in the flame retardancy of epoxy resins.     

含磷双环戊二烯酚醛固化剂的合成及固化环氧树脂的性能

合成了一种含磷酚醛型环氧树脂固化剂DCPD-DOPO,通过红外光谱和核磁共振谱对其化学结构进行了表征,采用凝胶渗透色谱测量了其相对分子质量。以DCPD-DOPO、苯酚型酚醛树脂(PF8020)或其复合物为固化剂,双酚A环氧树脂(DGEBA)为基料,制备了不同磷含量的阻燃环氧树脂。通过热重分析、差示扫描量热分析研究了环氧树脂固化物的热性能和阻燃性能;通过极限氧指数(LOI),垂直燃烧实验和锥形量热法研究了固化后环氧树脂固化物的燃烧特性。结果表明,DCPD-DOPO固化的环氧树脂的LOI可达31.6%,垂直燃烧性能达到UL94 V-0级,玻璃化转变温度(T_g)为133℃。采用DCPD-DOPO与PF8020复合物固化的环氧树脂的T_g提高到138℃以上,LOI值略有降低,但仍能通过UL 94V-0测试。DCPD-DOPO与PF8020添加DCPD-DOPO后,复合固化的环氧树脂的热释放速率峰值及总释热量较PF8020固化的环氧树脂大幅度降低。此外,还用Kissinger法对环氧树脂固化反应动力学进行了研究。     

含氟对苯型酚醛环氧树脂的制备与性能研究

将三氟甲基引入到对苯型酚醛环氧树脂体系的分子结构中,制备了新型舍氟对苯型酚醛环氧树脂(FPE)和含氟对苯型酚醛树脂固化剂(FPN).系统研究了含氟基团对环氧树脂固化物的耐热性能、力学性能和阻燃性能的影响规律,并对由其制备的环氧塑封料的综合性能进行了评价.结果表明,以含氟对苯型酚醛环氧树脂体系FPE/FPN制备的塑封料不但具有突出的绝缘性能,同时表现出优异的本征阻燃性.     

混合型固化剂对环氧树脂室温和低温力学性能的影响

研究了一种刚性和柔性胺混合型固化剂（芳香胺DETD和聚醚胺D-400）固化环氧树脂浇铸体的力学性能、材料断裂表面的微观形貌和玻璃化转变温度等性能。结果表明:当D-400加入量占固化剂总量的40%时,其室温拉伸强度呈现最大值,为82.52 MPa,弹性模量为2.30 GPa,与未加D-400的体系相比分别提高了6.3%和14.4%,其低温冲击强度提高了14%。对冲击断面形貌进行扫描电子显微分析表明:D-400的加入致使断口形貌变得粗糙,抗开裂能力得到提高。热分析实验结果显示,体系的玻璃化转变温度随着D-400含量的增加而降低。此外,还探讨了环氧树脂体系低温增韧机制。      

Thermodynamic and mechanical properties of amine-cured epoxy resins using group interaction modelling

The prediction of thermal and mechanical properties of amine-cured epoxy resins by group interaction modelling is presented. The derivation of the group interaction based approach to the prediction of macroscopic engineering properties of both linear and crosslinked epoxy resins is described with specific application to MY721 resin. The glass transition temperature, bulk and tensile modulus and linear thermal expansion coefficient of tetraglycidyl 4,4′-diaminodiphenylmethane (TGDDM) cured with 4,4′-diaminodiphenyl sulphone (DDS) are estimated using the model and compared with results from dynamic mechanical experiments. The glass transition of TGDDM/DDS is calculated to occur at approximately 248 °C and the reasons for a secondary peak in the spectrum cured to 180 °C are given. The bulk and tensile modulus of TGDDM/DDS are calculated to be 7.54 GPa and 5.34 GPa, respectively.