原位聚合法制备长玻纤增强ABS的研究

采用原位聚合方法制备长玻纤增强ABS复合材料,用DSC、接枝率、SEM等方法研究了基体ABS树脂的结构,表明原位聚合的基体ABS与通用ABS结构相似.用SEM、拉伸强度、弯曲强度、冲击强度等测试技术研究原位聚合制备的长纤维增强ABS复合材料的结构与性能.结果表明,原位聚合法制备的长纤维增强ABS复合材料具有良好的浸润性及优良的力学性能.     

高强玻纤增强ABS复合材料的制备及性能

以丙烯腈-丁二烯-苯乙烯共聚物(ABS)及玻璃纤维(GF)为原料,以苯乙烯-马来酸酐共聚物(SMA)和环氧树脂(E-poxyresin)作为界面相容剂,研究了界面相容剂对玻璃纤维增强ABS复合材料力学性能及界面粘接的影响。结果表明,加入SMA或环氧树脂,玻纤增强ABS复合材料的力学性能明显提高;SMA与环氧树脂复配有明显的协同效果,同时加入SMA和环氧树脂后的复合材料的性能更加优越,界面粘接性能得到很大的改善,在玻纤加入量为30%时,其拉伸强度、弯曲强度、冲击强度较未添加界面相容剂时分别提高了44%、29%、100%。     

适于快速成型制造工艺的短纤维增强复合材料研究

对短切玻璃纤维增强ABS 复合材料进行了一系列的改性研究。短切玻纤的加入, 能提高纯ABS 的强度、硬度且显著降低ABS 的收缩率, 减小制品的形变, 但同时使材料变脆。本实验通过适量加入增韧剂和增容剂, 较大提高了挤出的复合材料丝的韧性及力学性能, 从而使制备出的短切玻璃纤维增强复合材料适用于熔融沉积制造(FDM ) 工艺。并用改性了的短切玻璃纤维增强ABS 作为原料, 在快速成型机上制备试样, 测定其力学性能, 从宏观及微观上对改性效果进行了分析与评定。     

玻纤含量对玻纤增强聚丙烯拉伸性能的影响

采用不同玻纤含量的标准拉伸试样,应用试验方法,通过玻纤含量对玻纤增强PP复合材料的拉伸性能进行比较,找出了实现最佳抗拉强度的玻纤含量。     

改性处理对热塑性聚合物基复合材料性能的影响

研究了冷却方式及改性处理对玻纤增强热塑性聚合物复合材料性能的影响.采用模压工艺制备复合材料,研究冷却方式、偶联剂处理及等离子改性处理对玻纤增强聚丙烯力学性能的影响,并通过DSC分析复合体系结晶性能的变化规律.结果表明:采用同加热板一起冷却的复合材料结晶性能较好,材料的拉伸性能最高;改性处理在一定程度上改善了材料的界面结...     

硅烷偶联剂对玻璃纤维/聚氨酯复合材料性能的影响研究

采用硅烷偶联剂(KH550)对玻璃纤维进行表面处理,并对改性玻纤进行红外分析,结果证明硅烷偶联剂使玻璃纤维表面基团增加。用改性玻纤制备改性玻纤/聚氨酯复合材料,与原玻纤增强聚氨酯材料的力学性能及泡孔结构进行对比。结果表明:硅烷偶联剂处理能够提高玻璃纤维与聚氨酯基体的界面强度,改善玻璃纤维在聚氨酯基体中的分散情况,使玻璃纤维/聚氨酯复合材料的力学性能提高,同时改善复合材料的泡孔结构。     

玻纤增强注塑件的均匀化弹性力学参数研究

基于均匀化方法,根据长玻纤增强聚丙烯(LGFR-PP)的微观特征,建立了非连续长玻纤增强复合材料的代表性体积单元(RVE),通过有限元方法模拟预测了复合材料的宏观等效弹性力学参数,与注塑样条拉伸性能测试结果进行了比较。研究表明,通过在玻纤两侧增加聚丙烯(PP)分布,所采用的RVE较传统连续纤维的有限元模型更为合理;当玻纤成单一取向时,玻纤增强聚丙烯为一种横观各向同性材料;改变玻纤取向与拉伸方向之间的角度,拉伸方向的等效模量先微幅减小,再迅速降低,而后趋于稳定。利用均匀化方法预测非连续长玻纤增强注塑件的等效弹性力学性能具有较高的工程可行性,能进一步为玻纤增强注塑件的结构服役性能分析提供科学依据。     

玻纤增强HDPE气体辅助注射成型制品的形态

采用气体辅助注射成型(GAIM)和普通注射成型(CIM)制备了玻纤(GF)增强高密度聚乙烯(HDPE)复合材料。通过扫描电镜对复合材料中的玻纤取向进行了研究,发现CIM试样的玻纤仅在表层有轻微取向,而GAIM试样在整个横截面上玻纤均发生了明显的取向,且在次表层处取向强烈,排列十分规整。在此前研究工作的基础上,进一步探讨了玻纤取向结构的形成机理。     

静电植绒法处理多壁碳纳米管改性玻纤织物/环氧树脂复合材料的制备及力学性能

为提高玻纤增强环氧树脂复合材料的力学性能,采用静电植绒法将多壁碳纳米管(MWCNTs)附着在玻纤织物表面,得到改性的玻纤织物。利用一种低黏度的环氧树脂和所制得的改性织物,采用真空辅助成型工艺(VARI)制备了MWCNTs改性格玻纤织物/环氧树脂复合材料层合板,表征了层合板的力学性能。对进行力学实验后的MWCNTs改性玻纤织物/环氧树脂复合材料试样断口进行了SEM和OPM观察。结果显示:与未添加MWCNTs的玻纤织物/环氧树脂复合材料层合板相比,添加了MWCNTs的层合板的拉伸强度降低了10.24%,弯曲强度降低了13.90%,压缩强度降低了17.33%,拉伸模量和弯曲模量分别提高了19.38%和16.04%,压缩模量提高了13%;MWCNTs与玻纤织物之间的结合较弱,在拉伸作用下,存在明显的脱粘和分层;将改性玻纤织物在200℃下热压处理2h后,制备的MWCNTs改性玻纤织物/环氧树脂复合材料层合板的力学性能均有所提高,热压处理后树脂与玻纤织物之间的界面结合得到改善。     

SAG对长玻纤增强AS复合材料性能的影响

以苯乙烯-丙烯腈共聚物作为基体,苯乙烯-丙烯腈接枝甲基丙烯酸缩水甘油酯作为相容剂,热塑性弹性体聚氨酯作为增韧剂,采用熔体浸渍工艺制备了长玻纤增强苯乙烯-丙烯腈复合材料。研究了不同苯乙烯-丙烯腈接枝甲基丙烯酸缩水甘油酯用量对长玻璃纤维增强苯乙烯基-丙烯腈复合材料性能的影响。结果表明,随着相容剂含量的增加,长玻璃纤维增强苯乙烯-丙烯腈复合材料的机械力学和动态力学性能呈现先增大后降低的趋势;对长玻纤增强苯乙烯-丙烯腈复合材料的形态分析得出,添加相容剂后的玻璃纤维表面包覆了一层树脂。     

ABS/SBS和ABS/GF环状试样的疲劳性能

采用ABS/SBS和ABS/GF材料成型了圆环状试样,使用了自行设计的试验装置对环状试样进行疲劳试验,分析比较在环状下不同填料对ABS的疲劳性能的影响。从而获得ABS/SBS和ABS/GF环状试样在不同应力下的疲劳曲线和疲劳变化趋势。     

Tensile and flexural properties of injection-moulded short glass fibre and glass bead ABS composites in the presence of weldlines

The effect of weldline on tensile and flexural properties of ABS reinforced with short glass fibres (ABS/GF) and spherical glass beads (ABS/GB) was investigated as a function of glass fibre and glass bead concentrations. The weldline was formed in the moulded specimens by direct impingement of two opposing melt fronts (i.e. cold weld). It was found that elastic modulus of ABS/GF composites, with or without weldlines increased linearly with increasing volume fraction of fibres (ϕ_f), according to the rule-of-mixtures for moduli. The presence of weldline reduced tensile and flexural modulus of the ABS/GF composites. Weldline integrity factor for elastic modulus of ABS/GF composites decreased linearly with increasing ϕ_f. Results showed that tensile and flexural strength of ABS/GF increased with increasing ϕ_f in a nonlinear fashion. Flexural strength was consistently greater than tensile strength for the same ϕ_f. Weldline affected both strengths in a significant way; weldline integrity factor decreased with increasing ϕ_f and was independent of loading mode. Tensile and flexural modulus of ABS/GB composites increased linearly with increasing volume fraction of glass beads (ϕ_b), showing no loading mode dependency. Although modulus of the ABS/GB system was not affected significantly by the weldline, its strength was affected, and more so in flexure than in tension. Weld and unweld strengths decreased with increasing ϕ_b in both tension and flexure according to Piggott and Leidner relationship; for the same ϕ_b, flexural strength was always greater than tensile strength. Weldline integrity factor for tensile strength of ABS/GF system was considerably lower than that for ABS/GB system but weldline integrity factor for flexural strength was almost the same for the two composite systems.     

TLCP/GF/PP复合材料中纤维的主承载与微纤的作用

本文对热致液晶聚合物（TLCP）／玻璃纤维（GF）／聚丙烯（PP）原位混杂复合材料的形态结构，破坏过程，力学性能进行了研究，显微镜的观察结果表明，TLCP的加入使得加工过程中玻纤的破断减弱，TLCP／GF／PP原位混合复合材料中GF的平均长度是GF／PP复合材料的2．36倍。这使其主承载作用更显著，使用带拉伸实验台的扫描电镜观察到了TLCP微纤或微球对微裂纹扩展的阻滞及延缓作用。TLCP／GF／PP（5／15／85）样品拉伸强度度及断裂伸长度分别比GF／PP（15／85）样品提高了22．6％和321％，PP-g-MAH的加入使得原位混杂复合材料的拉伸强度进一步得到提高。     

Influence of weldlines on tensile properties of hybrid acrylonitrile butadiene styrene (ABS) composites filled with short glass fibres (GF) and glass beads (GB)

The present study investigated the effect of weldlines on tensile strength and modulus of injection moulded ABS polymer reinforced with both short fibres (GF) and spherical glass beads (GB). It was observed that tensile strength and modulus of ABS/GF/GB hybrids increased with increasing the concentration total of glass in the hybrid as well as the concentration of glass fibres in the hybrid (χ _GF ). Results indicated that tensile strength and modulus of ABS/GF/GB hybrids obey the rule-of-mixtures. The presence of weldlines had a negative effect on tensile properties of ABS/GF/GB hybrids. Although tensile strength and modulus of ABS/GF/GB hybrids were reduced in the presence of weldlines, nonetheless both increased with increasing the total concentration of the glass particles and χ _GF . The observed linearity of weldline strength and modulus with χ _GF indicated that these properties like their unweld counterparts can be expressed by simple rule-of-mixtures. It was noted also that weldline integrity factor for tensile modulus and strength decreased with increasing χ _GF and the total concentration of the glass particles in the hybrids. Weldline integrity values indicated that hybrid tensile strength was more affected by the weldlines than hybrid modulus.     

CPVC玻璃纤维增强塑料的耐腐蚀行为研究

本文首先用粘弹谱图说明了CPVC玻璃纤维增强塑料的动态力学性能,继而参考有关试验标准对这一材料耐水及耐稀酸、碱、盐溶液的腐蚀行为进行了研究,并通过扫描电镜(SEM)分析考察了腐蚀后材料的微观腐蚀形态.研究结果表明这一动态力学性能良好的增强塑料在70℃以下耐腐蚀性能良好,其腐蚀机理是物理渗透和化学作用并举.这一研究结果为今后这一材料的配制、成型与使用提供了基础数据.     

聚苯硫醚及其玻璃纤维增强复合材料力学性能研究

本文利用差示扫描量热仪(DSC)研究了国产低分子量聚苯硫醚及其固相热处理产物的热行为,并用悬浮-熔融法制备了玻璃纤维增强聚苯硫醚复合材料的预浸带,测定了其单向板的力学性能,观察了其断口形貌。结果表明:低分子量聚苯硫醚经过固相热处理后,其T_g、T_c上升,T_m下降;热处理后的聚苯硫醚玻纤复合材料在室温时的力学性能有很大程度的提高,其高温性能受玻璃化转变的影响显著;通过SEM观察断口发现其破坏主要属于界面脱粘。     

GF／PTT复合材料的力学性能和流变行为

采用扫描电子显微镜(SEM)和毛细管流变仪研究了玻璃纤维(GF)/聚对苯二甲酸丙二酯(PTT)复合材料的界面性能和流变行为。结果表明,材料断面较整齐,纤维与基体界面粘接牢固而拔出较少,表现出较强的整体承载负荷能力。部分暴露的GF表面仍附着大量树脂,说明纤维与基体间的界面粘接性能很好,GF的界面处理效果较好。复合材料熔体在剪切作用下为假塑性流体,表观黏度随剪切速率升高而下降。在相同剪切速率下,GF含量增加,非牛顿指数n增大,熔体黏度逐渐变小,且都低于纯PTT熔体黏度。粘流活化能随GF含量的增加先增加后降低。     

Effects of multi-walled carbon nanotube (MWCNT) dispersion and compatibilizer on the electrical and rheological properties of polycarbonate/poly(acrylonitrile–butadiene–styrene)/MWCNT composites

In this study, the effects of multi-walled carbon nanotube (MWCNT) dispersion and poly(styrene-co-acrylonitrile)-g-maleic anhydride (SAN-g-MAH) as a compatibilizer on the electrical conductivity, electromagnetic interference shielding effectiveness (EMI SE), and rheological properties of polycarbonate (PC)/poly(acrylonitrile–butadiene–styrene) (ABS)/MWCNT composites were investigated. The morphological results from the scanning and transmission electron microscope images showed that the droplet size of the ABS decreased when the SAN-g-MAH (5 phr) was added to the PC/ABS (80/20) blend. This result suggests that the SAN-g-MAH acts as an effective compatibilizer in the PC/ABS blend. Also, the MWCNT appeared to be located more in the ABS phase (dispersed phase) than in the PC phase (continuous phase). The interfacial tension of the ABS/MWCNT composite was lower than that of the PC–MWCNT composite, and the lower value of interfacial tension of the ABS/MWCNT composite affected the preferred location of the MWCNT in the ABS phase more than in the PC phase. The electrical conductivities and EMI SE of the PC/ABS/MWCNT composite with the compatibilizer were higher than those of the composite without compatibilizer. The complex viscosity of the PC/ABS/MWCNT composite containing the SAN-g-MAH increased with the frequency compared to that of the composite without SAN-g-MAH. This result is possibly due to the increased degree of MWCNT dispersion. The result of rheological properties is consistent with the results of the morphology, electrical conductivity, and EMI SE of the PC/ABS/MWCNT composite.     

Design of low temperature self-cured phthalonitrile-based polymers for advanced glass fiber composite laminates

Self-promoted copolymerization behavior and processability of phthalonitrile oligomer/phthalonitrile containing benzoxazine (Po/BA-ph) system were investigated by differential scanning calorimetry and dynamic rheological analysis. The results revealed that Po/BA-ph systems exhibited double-stage curing behaviors which corresponded to the ring-opening polymerization of benzoxazine rings and ring-formation polymerization of nitrile groups. Compared with Po, processability of Po/BA-ph blends was improved and could be tuned by varying BA-ph contents, processing temperature, and time. The structures of the copolymers were also characterized and discussed to further confirm the copolymerizing behaviors. Then Po/BA-ph copolymers were employed to prepare Po/BA-ph/glass fiber (GF) composite laminates, and their mechanical and thermal properties were investigated. Compared with those of Po/GF composites, the flexural strength and modulus of Po/BA-ph/GF composites were increased by 6.5 and 25 %, respectively. All of the Po/BA-ph/GF composite laminates were stable up to 430 °C in air. The systematic study of Po/BA-ph system could enrich the thermosetting resin/thermosetting resin systems in industrial applications. Meanwhile, the outstanding mechanical properties and thermal stabilities enable the Po/BA-ph/GF composite laminates to be further applied in the areas which require excellent mechanical properties and high temperature resistance.