聚醚酰亚胺改性双马来酰亚胺树脂体系的研究

利用共混溶液法制备了共聚双马来酰亚胺／聚醚酰亚胺（PEI）树脂体系。结果表明，PEI是该体系的有效增韧剂。当加入不同含量的改性剂时，通过扫描电镜，可观察到固化物以富热塑性球形颗粒为分散相，富双马树脂相为连续相的两相结构及“韧性网络一球状颗粒”的相反转结构。当加入12．5phr PEI时，体系为“韧性网络一球状颗粒”结构，韧性达到最优，断裂韧性G忙达到805J／m^2，为未改性时的5倍，冲击强度达到13．2kJ／m^2，比未改性时的提高20％。     

聚酰胺酰亚胺对BMI/DP共聚树脂的增韧研究

以DP(二烯丙基双酚A)为BMI(双马来酰亚胺)的共聚改性剂,制备BMI/DP共聚树脂;然后以PAI(聚酰胺酰亚胺)为增韧改性剂,制备PAI增韧改性BMI/DP共聚树脂。研究结果表明:当w(PAI)=3%(相对于共聚树脂质量而言)时,改性树脂具有较好的增韧效果;此时,其冲击强度(11.81 kJ/m2)提高了19%以上,KIC(临界应力强度因子)值(1.45 MPa.m0.5)和GIC(临界应变能释放率)值(351.4 J/m2)均比增韧前提高了30%以上,表现出较好的断裂韧性,并且其断面为典型的韧性破坏;其Tg(玻璃化转变温度)达到了252.5℃,5%热失重温度仍超过405℃,说明其耐热性几乎没有下降。     

聚醚酰亚胺对共聚双马来酰亚胺树脂的增韧作用

采用二烯丙基双酚A、烯丙基酚醛改性4,4'-二氨基二苯甲烷双马来酰亚胺共聚制备了一类新型的双马来酰亚胺树脂(简称ABD)。以ABD为基体,选用热塑性树脂聚醚酰亚胺(PEI)为增韧剂,采用共混法制备了共聚双马来酰亚胺/聚醚酰亚胺(PEI)树脂体系。采用DSC和流变仪对ABD树脂的固化行为进行了研究,结果表明,该树脂粘度较低,室温下为液态,树脂的冲击强度为8.99 kJ/m2。通过DMA、TGA和扫描电镜对PEI加入量对树脂热性能和微观形貌的影响表明,添加质量分数为15%聚醚酰亚胺时,树脂冲击强度达到16.9 kJ/m2,比基体树脂提高了88%。     

含醚键双马树脂改性氰酸酯树脂研究

合成了二苯醚双马(DEB)和双二苯醚双马树脂(BMPB),采用动态热机械分析和热重分析方法研究了两种双马树脂的玻璃化转变温度(Tg)和耐热性,并与二苯甲烷双马(BMP)进行了对比。将DEB和BMPB分别与二烯丙基双酚A(DBA)配合用于双酚A型氰酸酯(CE)共聚改性,研究了共聚树脂的动态热机械性能、耐热性和力学性能。结果表明,DEB和BMPB的玻璃化转变温度分别为280℃和300℃,低于BMP的324℃。DEB和BMPB的5%热失重温度与BMP基本相同,但800℃残碳率高于BMP。采用20phr的双马来酰亚胺配合DBA改性CE,DEB/DBA/CE和BMPB/DBA/CE的Tg与BMP/DBA/CE相近,弹性模量略低于BMP/DBA/CE。DEB/DBA/CE和BMPB/DBA/CE的断裂伸长率和冲击强度相比于BMP/DBA/CE有较大提高,其中BMPB/DBA/CE的冲击强度达20.4k J·m^-2,相比于BMP/DBA/CE提高61%,显示出含有双醚键的双马来酰亚胺对氰酸酯材料优异的增韧特性。     

EP/苯酚-苯胺型单环苯并噁嗪树脂共聚体系研究

采用无溶剂法合成了苯酚-苯胺型单环苯并噁嗪树脂(P-a),然后将其与环氧树脂(EP)进行共聚,并采用差示扫描量热(DSC)法对该共聚体系的固化特性进行了研究。结果表明:不同P-a/EP质量比的复合材料体系,其冲击强度由纯EP体系的16.12 kJ/m2分别降至14.51 kJ/m2(质量比10%)、13.90 kJ/m2(质量比30%)和14.15 kJ/m2(质量比50%);纯EP体系的弯曲强度和弯曲模量分别为100.56 MPa和3.46 GPa,而P-a/EP体系的最大弯曲强度和弯曲模量分别为110.26 MPa和3.84 GPa;EP/P-a体系含氮量最高为3.52%,但各组试样均燃尽,说明单纯增加树脂体系的氮含量并不能有效提高其垂直燃烧性能。     

不同分子量的PEI对乙烯基酯树脂力学性能的影响

制备了4种分子量不同的刚性聚醚酰亚胺齐聚物(PEI),研究了不同分子量的PEI改性乙烯基酯树脂对其固化物力学性能的影响.结果表明:分子量不同的PEI在最佳含量改性乙烯基酯树脂固化物时弯曲强度变化不大,均在105MPa左右;冲击韧性则有大幅度的提高,其中当PEI相对分子质量为1373.1,特性黏度为5.3dL/g,质量含量占15%时,冲击韧性达到16.8kJ/m2,约为未改性树脂(冲击韧性为3.8kJ/m2)的5倍.     

萘酚改性烯丙基化环保型酚醛树脂的合成及研究

分别以环保型PF(酚醛树脂)和萘酚改性环保型PF为母体,成功合成了烯丙基化PF和萘酚改性烯丙基化PF,并制备了萘酚改性烯丙基化PF/BMI(双马来酰亚胺)共聚树脂;然后分别以上述树脂作为基体树脂,制备了玻璃纤维增强型复合材料。结果表明:当基体树脂为萘酚改性烯丙基化PF/BMI共聚树脂时,相应复合材料的冲击强度(321.6 kJ/m2)和弯曲强度(524.1 MPa)比萘酚改性烯丙基化PF基复合材料提高了11.0%和46.3%,比未改性环保型烯丙基化PF基复合材料提高了42.8%和258.2%,说明萘酚改性烯丙基化PF/BMI共聚树脂的增韧效果优于萘酚改性烯丙基化PF;萘酚改性烯丙基化PF/BMI共聚树脂基复合材料的耐热性能优于未改性烯丙基化PF体系,这是因为前者800℃时的残炭率(39.62%)高于后者(10.92%)所致。     

Ti_2AlC/TiAl_3复合材料的制备及其性能研究

利用Ti-Al-TiC-CNTs体系的原位反应结合热压技术制备Ti2AlC/TiAl3复合材料。研究产物的相组成、结构和力学性能。结果表明:产物主要由TiAl3和Ti2AlC相组成,增强相Ti2AlC主要分布在基体晶界处,并形成了明显的搭接层状结构。产物的弯曲强度和断裂韧性分别为343.21 MPa和6.5 MPa·m1/2,远高于TiAl3合金的弯曲强度(162 MPa)和断裂韧性(2 MPa·m1/2),较TiAl3合金分别提高了111.86%和225%。     

双马来酰亚胺改性芳香胺固化环氧树脂的研究

针对环氧树脂(EP)耐湿热性差和韧性不足的缺点,用双马来酰亚胺(BMI)对常用的芳香族二元胺(DA)固化剂进行扩链改性。研究了改性4,4′-二氨基二苯砜(DDS)固化剂对7种环氧树脂固化物的力学性能、热性能和工艺性能的影响,优化出一种BMI改性环氧树脂基体。改性树脂浇铸体韧性好、耐热性高,断裂韧性GIC195J/m2,断裂延伸率3.37%,Tg218℃,135℃弯曲强度保持率72.2%,沸水饱和吸湿率3.3%;其碳纤维复合材料综合性能良好、断裂韧性高、耐湿热性好,横向拉伸强度75.5MPa,层间断裂韧性GIC267J/m2,135℃湿态弯曲强度保持率70.5%,132℃湿态层间剪切强度保持率49.5%。     

乙烯基橡胶增韧双马来酰亚胺树脂的研究

采用二烯丙基双酚A(DP)与乙烯基橡胶对两种结构类型双马树脂进行增韧。探讨了乙烯基橡胶用量对改性树脂的力学性能、耐热性能及玻璃化转变温度的影响,确定当乙烯基橡胶用量为5%(占双马树脂)时,改性树脂具有较好的综合性能,较未增韧前有大幅提高。此时,冲击强度为23.17kJ/m2,GIC值为338.5J·m-2,玻璃化转变温度为241℃,5%热失重温度约在420℃。同时,通过SEM观察其断面的微观形貌为典型的韧性破坏。     

Polyetherimide‐modified bismaleimide resins. II. Effect of polyetherimide content

A novel polyetherimide was prepared and used to improve the toughness of bismaleimide resin composed of bis(4‐maleimidediphenyl) methane and O,O′‐diallyl bisphenol A. The morphologies of the modified resins change from spherical particles to an inverted phase structure, depending on the modifier's content based on the scanning electronic microscopy results. Dynamic mechanical analysis is also used to characterize morphologies of the modified resins. The phase‐separation process of the modified system is traced by time‐resolved light scattering. The change in the light‐scattering profile with curing time showed that the phase separation mechanism depended on the modifier concentration. Phase separation took place via the spinodal decomposition mechanism in the PEI 15‐phr‐ and 20‐phr‐modified system. The fracture energy (G_IC) increased with PEI content in the modified system; in the PEI 15‐phr‐modified system, the G_IC value was three times greater than that of the unmodified BMI resin. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 350–358, 2001     

Toughening of bismaleimide resin by modification with poly(ethylene phthalate) and poly(ethylene phthalate-co-ethylene isophthalate)

Aromatic polyesters were prepared and used to improve the brittleness of the bismaleimide resin composed of 4,4′-bismaleimidediphenyl methane and o,o′-diallyl bisphenol A. The aromatic polyesters contain poly(ethylene phthalate) (PEP) and poly(ethylene phthalate-co-ethylene isophthalate) (10 mol % isophthalate unit) (PEPI). PEP and PEPI were effective modifiers for improving the brittleness of the bismaleimide resin. The most suitable composition for the modification of the bismaleimide was inclusion of 20 wt % PEP (MW 18,200), which led to an 80% increase in the fracture toughness with retention of flexural properties and a slight decrease in the glass transition temperature, compared with the mechanical and thermal properties of the unmodified cured bismaleimide resin (Matrimid resin). Microstructures of the modified resins were examined by scanning electron microscopy and dynamic viscoelastic analysis. The thermal stability of the modified resin was slightly lower than that of the unmodified resin by thermogravimetric analysis. The toughening mechanism is discussed in terms of the morphological and dynamic viscoelastic behavior of the modified bismaleimide resin system. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 1349–1357, 1997     

Modification of three‐component bismaleimide resin by poly(phthaloyl diphenyl ether) and related copolymers

A three‐component bismaleimide resin, composed of 4,4′‐bismaleimidodiphenyl methane (BDM), o,o′‐diallyl bisphenol A (DBA), and o,o′‐dimethallyl bisphenol A (1.0/0.3/0.7 eq ratio) was used as a parent bismaleimide resin. Modification of the three‐component bismaleimide resin was examined by blending it with poly(ether ketone ketone)s. Poly(ether ketone ketone)s include poly(phthaloyl diphenyl ether) (PPDE), poly(phthaloyl diphenyl ether‐co‐isophthaloyl diphenyl ether) (PPIDE), and poly(phthaloyl diphenyl ether‐co‐terephthaloyl diphenyl ether) (PPTDE). The PPIDE (51 mol % isophthaloyl) and PPTDE (44 mol % terephthaloyl) were more effective as modifiers for the bismaleimide resin than was PPDE. For example, the fracture toughness (K_IC) for the modified resin increased 30% with no deterioration in the flexural strength and modulus with a 15 wt % inclusion of PPTDE (MW 23,400) compared to the parent three‐component bismaleimide resin: the K_IC increased 95% compared to the value for the Matrimid 5292 resin composed of BDM and DBA. The morphologies of the modified resins changed from particulate to cocontinuous phase structures, depending on the modifier structure and concentration. Toughening of the cured bismaleimide resin could be achieved because of the cocontinuous phase structure. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2991–3000, 2001     

Modification of bismaleimide resin by poly(ethylene phthalate‐co‐ethylene terephthalate), poly(ethylene phthalate‐co‐ethylene 4,4′‐biphenyl dicarboxylate), and poly(ethylene phthalate‐co‐ethylene 2,6‐naphthalene dicarboxylate)

Aromatic polyesters were prepared and used to improve the brittleness of bismaleimide resin, composed of 4,4′‐bismaleimidodiphenyl methane and o,o′‐diallyl bisphenol A (Matrimid 5292 A/B resin). The aromatic polyesters included PEPT [poly(ethylene phthalate‐co‐ethylene terephthalate)], with 50 mol % of terephthalate, PEPB [poly(ethylene phthalate‐co‐ethylene 4,4′‐biphenyl dicarboxylate)], with 50 mol % of 4,4′‐biphenyl dicarboxylate, and PEPN [poly(ethylene phthalate‐co‐ethylene 2,6‐naphthalene dicarboxylate)], with 50 mol % 2,6‐naphthalene dicarboxylate unit. The polyesters were effective modifiers for improving the brittleness of the bismaleimide resin. For example, inclusion of 15 wt % PEPT (MW = 9300) led to a 75% increase in fracture toughness, with retention in flexural properties and a slight loss of the glass‐transition temperature, compared with the mechanical and thermal properties of the unmodified cured bismaleimide resin. Microstructures of the modified resins were examined by scanning electron microscopy and dynamic viscoelastic analysis. The toughening mechanism was assessed as it related to the morphological and dynamic viscoelastic behaviors of the modified bismaleimide resin system. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2352–2367, 2001     

Modification of bismaleimide resin by poly(phthaloyl diphenyl ether) and the related copolymers

Poly(ether ketone ketone)s were prepared and used to improve the brittleness of the bismaleimide resin. The bismaleimide resin was composed of 4,4′-bismaleimidediphenyl methane (BMI) and o,o′-diallyl bisphenol A (DBA). Poly(ether ketone ketone)s include poly(phthaloyl diphenyl ether) (PPDE), poly(phthaloyl diphenyl ether-co-isophthaloyl diphenyl ether) (PPIDE), and poly(phthaloyl diphenyl ether-co-terephthaloyl diphenyl ether) (PPTDE). PPIDE (50 mol % isophthaloyl unit) was more effective as a modifier for the bismaleimide resin than were PPDE and PPTDE (50 mol % terephthaloyl unit). Morphologies of the modified resins changed from particulate to cocontinuous and to phase-inverted structures, depending on the modifier structure and content. The most effective modification for the cured resins could be attained because of the cocontinuous phase or phase-inverted structure of the modified resins. For example, when using 10 wt % of PPIDE (50 mol % IP unit, MW 349,000), the modified resin had a phase-inverted morphology and the fracture toughness (K_IC) for the modified resins increased 75% with retention in flexural properties and the glass transition temperature, compared to those of the unmodified cured bismaleimide resin. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:769–780, 1998     

Modification of bismaleimide resin by poly(propylene phthalate), poly(butylene phthalate) and related (co)polyesters

Aromatic polyesters were prepared and used to decrease the brittleness of the bismaleimide resin composed of 4,4′-bismaleimidediphenyl methane (BMI) and o,o′-diallyl bisphenol A (DBA) (Matrimid 5292 resin). The aromatic polyesters included poly(propylene phthalate) (PPP), poly(2,2-dimethylpropylene phthalate) (PDPP), poly(butylene phthalate) (PBP) and poly(butylene phthalate-co-butylene terephthalate) (50mol% terephthalate unit) (PBPT). The polyesters were effective modifiers for decreasing the brittleness of the bismaleimide resin. For example, inclusion of 20wt% PPP (MW 18700) led to 50% increase in the fracture toughness (K_IC) with retention of flexural properties and a slight loss of the glass transition temperature, compared with the mechanical and thermal properties of the unmodified cured bismaleimide resin. Micro-structures of the modified resins were examined by scanning electron microscopy and dynamic viscoelastic analysis. The thermal stability of the modified resins was slightly lower than that of the unmodified resin as determined by thermogravimetric analysis. The toughening mechanism is discussed in terms of the morphological and dynamic viscoelastic behaviour of the modified bismaleimide resin system. © 1998 SCI.     

双马来酰亚胺改性苯并噁嗪树脂的力学性能及摩擦性能

苯并噁嗪(BOZ)树脂作为一种新型的热固性PF(酚醛树脂),具有诸多优异性能,但其韧性和耐磨性较差。以AE-BMI(含烯丙基醚的双马来酰亚胺预聚体)为改性剂制备AE-BMI/BOZ改性树脂,并对其力学性能和摩擦性能进行了研究。结果表明:适量的AE-BMI对BOZ树脂具有明显的增韧增强作用,并且其耐磨性也明显提高;当w(AE-BMI)=15%时,AE-BMI/BOZ改性体系的弯曲强度(125.53 MPa)和冲击强度(11.57 kJ/m2)分别比纯BOZ体系提高了57%和60%,并且其摩擦因数(0.27)和磨损率[18.50×10-6mm3/(N.m)]分别比纯BOZ体系降低了15.6%和50.6%。     

Mechanical properties and morphology of poly(ethylene glycol)‐side‐chain‐modified bismaleimide polymer

Two maleimido‐end‐capped poly(ethylene glycol) (m‐PEG)‐modified bismaleimide (BMI) resins [4,4′‐bismaleimido diphenylmethane (BDM)] were synthesized from poly(ethylene glycol) (PEG) of two different molecular weights. A series of m‐PEGs and unmodified BDM were blended and thermally cured. The effect of incorporating m‐PEG side chains on the morphology and mechanical behaviors of BMI polymer were evaluated. The mechanical properties of these m‐PEG‐modified BMIs that were evaluated included flexural modulus, flexural strength, strain at break, fracture toughness, and fracture energy. The morphology of these blends was studied with scanning electron microscopy. All the m‐PEG‐modified BMI polymers showed various degrees of phase separation depending on the molecular weights and concentrations of the m‐PEG used. The effects of these morphological changes in the m‐PEG‐modified BMI polymers were reflected by the improved fracture toughness and strain at break. However, there was a reduction in the flexural moduli in all m‐PEG‐modified BMI polymers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 715–724, 2002