混合纤维对尼龙66的增刚研究

以尼龙66（PA66）为基体,研究和分析玻璃纤维和碳纤维混杂对尼龙66增刚的影响.固定玻璃纤维质量分数为24.6%,改变碳纤维的质量分数,将玻璃纤维（GF）、碳纤维（CF）先用硅烷偶联剂KH550进行表面处理,用双螺杆挤出造粒和注塑成型方式制备GF/CF增刚PA66复合材料,对试样进行拉伸模量、拉伸强度、弯曲模量、弯曲强度、缺口冲击强度等性能测试,并利用扫描电镜分析复合体系的冲击断面特征.研究结果表明：GF/CF混合纤维对PA66具有很好的增刚效果.     

高抗冲PP/滑石粉复合材料的研究

研究滑石粉的不同质量分数对PP材料力学性能的影响．发现当滑石粉质量分数大于10％时，拉伸强度随其含量的增加而逐渐降低，冲击强度逐渐降低．针对大量滑石粉填充PP后力学性能下降很大，采用两种大分子接枝物和两种弹性体对含质量分数30％的滑石粉的PP复合材料进行增韧，结果表明在增韧剂质量分数小于30％时，EPDM-g-MAH的增韧效果明显好于POE-g-MAH。而POE的增韧效果要好于EPDM；通过扫描电镜观察增韧后复合材料冲击断面的形状，得出增韧后的滑石粉能够均匀分布于基体树脂中，并且相界面明显改善，     

钛酸钾晶须—橡胶—尼龙66体系的力学性能

考察了钛酸钾晶须－马来酸酐接枝三元乙丙橡胶－尼龙66体系的力学性能,探讨了晶须对改性橡胶－尼龙体系的增强作用以及改性橡胶对晶须－尼龙体系的增韧作用。研究表明,晶须对橡胶－尼龙体系的增强效果在橡胶含量少时较明显,体系中改性橡胶含量赵多,其冲击强度随体系中晶须含量增加下降的幅度越大,而弯曲与接伸强度随晶须含量增加上升的幅度越小。改性橡胶对晶须－尼龙体系也具有一定的增韧作用。     

增容剂对三元乙丙橡胶/尼龙共混胶相态及性能的影响

探讨了不同种类的增容剂对三元乙丙橡胶/尼龙(EPDM/PA)硫化胶物理机械性能和共混胶相态的影响。结果表明:增容剂为CPE时,硫化胶的拉伸永久形变值最小;增容剂为EPDM-g-MAH时,硫化胶的拉伸强度和撕裂强度最大,DIN磨耗值最小;增容剂为POE-g-MAH时,硫化胶的扯断伸长率最大。在DSC分析中,增容剂POE-g-MAH使共混胶中两相的玻璃化转变温度值靠近最大。从扫描电镜照片中看出,增容剂EPDMg-MAH对两相相容性的提高最明显。     

无卤阻燃低密度聚乙烯的增韧研究

目的为提高无卤阻燃材料的拉伸强度、断裂伸长率、冲击强度及阻燃性能.方法选用增容物三元乙丙橡胶接枝马来酸酐(EPDM-g-MAH)、乙烯-辛烯共聚物接枝马来酸酐(POE-g-MAH)和乙烯-辛烯共聚物(POE),加入到基体树脂中减少材料的力学性能损失;对原位反应增容方法进行改性,以过氧化二异丙苯(DCP)为引发剂,丙烯酸甲酯(MMA)和马来酸酐(MAH)为单体制备原位增容阻燃材料.结果在增容物增韧条件下,增韧效果为POE>EPDM-g-MAH>POE-g-MAH;在原位增容反应中,当DCP用量为2.0 g、单体MMA为20 mL、MAH为25 g时原位反应制得材料的性能最佳:拉伸强度为15.74 MPa、断裂伸长率为134.81%、冲击强度为40.84 kJ/m2、垂直燃烧等级达到UL94V-0级.结论增容物的加入能显著提高材料的冲击性能;原位反应中引发剂和单体之间的比例对材料的力学和阻燃性能有一定的影响.     

超临界流体制备PLA/SEBS-g-MAH发泡材料

采用熔融共混法制备了聚乳酸/SEBS-g-MAH共混材料,将其在超临界二氧化碳流体下进行发泡,研究了SEBS-g-MAH含量对聚乳酸/SEBS-g-MAH体系的力学性能、动态机械性能、热稳定性能和发泡性能的影响。研究结果表明:随着SEBS-g-MAH含量的增加,共混物的拉伸强度减小、断裂伸长率显著增加;加入SEBS-g-MAH后,聚乳酸的储能模量增加,损耗因子减小;共混材料的初始分解温度较纯聚乳酸的初始分解温度增加;SEBS-g-MAH含量越高,SEBS-g-MAH在聚乳酸相中的分布越均匀,共混体系发泡后泡孔尺寸变化明显,发泡材料的密度越来越大,SEBS-g-MAH的加入改善了聚乳酸的发泡性能。     

AS/POE共混体系的增容增韧改性研究

研究乙烯-辛烯共聚物(POE)用不同相容剂增容对AS(苯乙烯-丙烯腈共聚物)增韧效果的差异及其对共混体系力学性能和熔体流动速率的影响,用SEM和DSC研究共混体系的相容性.比较接枝率为1.0%的PE-g-MAH、接枝率为1.8%的PE-g-MAH、接枝率为1.2%的POE-g-MAH三种相容剂对POE/AS共混体系力学性能、熔体流动速率的影响.研究表明:相容剂的加入进一步提高了共混体系的冲击强度,起到了增容的作用,拉伸强度和熔融指数均有所下降.     

无卤阻燃聚丙烯复合材料的制备研究

为获得较好阻燃性能的聚丙烯(PP)复合材料,实验通过加入较大量的无机复合阻燃剂以实现其阻燃性能,加入大分子的增容物以提高体系的韧性,加入大分子的接枝物以改善无机粒子和聚合物之间的相容性,从而弥补因为加入大量无机阻燃剂引起的机械性能的损失.当m(氢氧化镁)∶m(氢氧化铝)为4∶1,硼酸锌加入35 g,红磷加入65 g时,材料的阻燃性能满足垂直燃烧等级UL-94,为V-0级,机械性能也较好;当增韧体系m(乙烯-辛烯共聚物)∶m(三元乙丙橡胶)(m(POE)∶m(EPDM))为110∶30时,制得的聚丙烯复合材料的综合性能较好,拉伸强度为19.35MPa,断裂伸长率可达到350.47%,冲击强度可达到35.23 kJ/m2,阻燃性能仍然保持在垂直燃烧等级UL-94,为V-0级.所以,无机阻燃剂氢氧化镁、氢氧化铝、红磷和硼酸锌一起使用可以达到很好的阻燃效果,通过大分子增容剂对PP无卤阻燃体系进行增韧,可以同时满足PP复合材料的阻燃性能和机械性能.     

碳酸钙和乙烯-辛烯共聚物对废旧聚丙烯塑料的改性

研究了废旧聚丙烯塑料的共混工艺、增强增韧改性及共混物的流动性能.以废旧聚丙烯塑料为研究对象,加入无机填料碳酸钙,增韧剂乙烯-辛烯共聚物及适量相容剂马来酸酐接枝聚丙烯对其进行增强增韧改性,通过熔融共混法制备了聚丙烯/碳酸钙、聚丙烯/碳酸钙/乙烯-辛烯共聚物两种复合材料.结果表明:碳酸钙和乙烯-辛烯共聚物对废旧聚丙烯塑料均有良好的的增韧效果,马来酸酐接枝聚丙烯作为聚丙烯/碳酸钙复合体系的界面改性剂能有效改善分散相碳酸钙在连续相聚丙烯中的分散状态,但乙烯-辛烯共聚物的加入会降低复合材料的拉伸强度,且共混体系的流动性能也有明显的降低趋势.当聚丙烯/碳酸钙/乙烯-辛烯共聚物质量份数比为100/15/10时,两种复合材料的悬臂梁缺口冲击强度均达到最大值,增韧效果最佳,弯曲强度和模量也有一定程度的提高,复合材料表现出良好的综合力学性能.     

PES/PEK改性BMI树脂的性能研究

采用熔融预聚法制备N,N’-4,4’-二苯甲烷双马来酰亚胺(BMI)/二烯丙基双酚A(DBA)/聚醚砜(PES)/聚醚酮(PEK)(简称B/D/P/P)改性树脂体系。研究了改性树脂的固化反应性、力学性能及热稳定性。并对不同配比PES/PEK增韧后树脂体系的性能进行比较。结果表明,PEK/PES的加入能明显提高树脂的韧性和强度。在合适的配比下,5wt%PEK/PES的加入就可使改性体系较纯的基体树脂体系冲击强度增加68.5%,弯曲强度增加50.8%。另外,改性树脂体系的热稳定性也较纯的体系以及单一热塑性塑料改性体系有所提高。PES/PEK同时加入效果比PES和PEK单个加入的改性效果明显。     

有机累托面/聚烯烃弹性体协同增韧补强聚丙烯的研究

分别研究了有机累托石粘土(OREC)、聚烯烃弹性体(POE)改性的聚丙烯(PP)以及POE／OREC／PP三元改性体系的冲击强度、拉伸强度及断裂伸长率。结果表明，在粘土添加量为2phr时(per hundred resin)可对PP同时实施增强、增韧。OREC与POE有协同增韧PP的作用。在OREC添加2phr时，POE／OREC／PP复合材料的强度大于相同用量的POE／PP二元体系的强度。在三元体系中，当POE用量15phr时，复合材料的冲击强度比纯PP提高204％，比POE／PP提高15．6％，拉伸强度比纯PP下降15．6％，比POE／PP提高22．6％。扫描电子显微镜分析(SEM)表明，三元体系呈现多相分散，在研究范围内，分散相尺寸越大，粒径分布越宽，复合材料的韧性越高。     

四氢呋喃聚醚型聚氨酯预聚体增韧双酚A型氰酸酯树脂

以本体树脂双酚A型氰酸酯树脂(BCE)为扩链剂,改性四氢呋喃聚醚型聚氨酯预聚体(A)得到改性预聚体BA,用BA与BCE共聚共混以改善BCE树脂的韧性。确定了BCE/BA的固化工艺,考察了共聚共混体系静态力学性能、动态力学性能及热性能。结果表明,用BA与BCE树脂共聚共混,可有效提高氰酸酯树脂基体的韧性和强度。当BA用量为10份时,BCE/BA体系的冲击韧性比纯树脂提高了64%;当BA用量为20份时,增强增韧效果最佳,BCE/BA体系的冲击韧性可达14.5 kJ.m-2,比纯树脂提高了142%;弯曲强度为128 MPa,比纯树脂提高了23%。     

不饱和聚酯挡风抑尘板力学性能研究

以玻璃纤维毡为增强骨架,不饱和聚酯树脂为基体材料,制备挡风抑尘板,并对不饱和聚酯树脂与玻璃纤维的配比、玻璃纤维的种类和固化剂、促进剂含量对挡风抑尘板力学性能的影响进行了研究。结果表明,当不饱和聚酯与玻璃纤维毡的质量比达到3∶1时,其拉伸强度和冲击强度都达到最大。高碱、中碱和无碱的玻璃纤维毡增强的挡风抑尘板拉伸强度分别达到55.198,75.249,89.446MPa,冲击强度分别达到30.699,35.367,41.343kJ/m2。而无碱玻璃纤维毡其拉伸强度比高碱提高了62%,比中碱提高了18.8%。冲击强度比高碱提高了34.7%,比中碱提高了16.9%。当促进剂质量分数为0.5%、固化剂质量分数为1%时,挡风抑尘板的拉伸强度最大为89.446MPa,冲击强度最大为41.343kJ/m2。     

Microstructure and mechanical properties of poly (vinyl chloride) modified by silica fume / acrylic core-shell impact modifier blends

This research explored replacing acrylic core-shell impact modifier (AIM) by silica fume to toughen PVC. 100%, 75%, 50% and 25% of AIM (8 phr) were substituted by silica fume in PVC respectively, and then processed by dry blending and twin-screw extrusion. Severe silica fume agglomeration was observed by scanning electron microscope (SEM) in the PVC matrix when 8 phr pure silica fume was used and processed by screw speed of 20 rpm. Its tensile strength was thereby reduced by 38% comparing to unmodified PVC. The silica fume was successfully dispersed while the screw speed was slowed down to 10 rpm to give a stronger screw torque and a longer melt residential time in the extruder. The tensile strength was ’recovered’ to a level comparable to unmodified PVC. Impact test were performed on all formulations extruded at 10 rpm screw speed and synergetic toughening effect was found with 50% substitution and it had the impact strength that was comparable to 8 phr pure AIM toughened PVC.     

Improving interlaminar fracture toughness of flax fiber/epoxy composites with chopped flax yarn interleaving

In this research, unidirectional flax fabrics reinforced epoxy laminates were interleaved with randomly oriented chopped flax yarns at various yarn lengths and contents. Mode I interlaminar fracture toughness of the laminates was evaluated via Double Cantilever Beam(DCB) tests. The results showed that Mode I interlaminar fracture toughness increased with the introduction of the chopped yarns. With moderate yarn length and content, the best toughening effect(31% improvement in Mode I interlaminar fracture toughness) was achieved. It was observed with the aid of Scanning Electronic Microscopy(SEM) that the introduction of the chopped yarns resulted in more tortuous in-plane crack propagation paths as well as the "trans-layer" phenomenon and fiber bridging effect of both the unidirectional yarns and the chopped yarns. These hindered the growth of the crack and led to more energy dissipation during delamination progress. Excessive yarn length or content would induce unstable crack propagation and thus weakened the toughening improvement. No remarkable change was found in the tensile properties and the Charpy impact strength for the interleaved laminates, which indicated that this interleaving method was effective on interlaminar toughening without sacrificing the comprehensive mechanical properties of the laminates.     

P（3HB-co-4HB）／PLA共混物的扩链改性研究

以异佛尔酮二异氰酸酯（IPDI）和亚磷酸三苯酯（TPP）为扩链剂,对聚（3-羟基丁酸酯-co-4-羟基丁酸酯）／聚乳酸[P（3HB-co-4HB）／（PLA）]共混物进行扩链改性．采用毛细管流变仪、电子万能试验机、差示扫描量热仪和扫描电子显微镜等研究两种扩链剂及用量对扩链前后共混物的流变性能、力学性能、结晶性能及断面形态的影响．结果表明：两种扩链剂均显著提高了共混物的熔体剪切黏度和两组分间的相容性,IPDI和TPP添加量分别为1．5份和1．0份时,改性效果最明显,共混物断裂伸长率及缺口冲击强度分别提高了34．5％、69．6％和89．6％、81．0％;IPDI扩链体系的拉伸强度提高8．3％,而TPP扩链体系的拉伸强度略有下降,表明IPDI扩链效果优于TPP．     

Chemical and thermal resistance of basalt fiber in inclement environments

To study the applicability of the basalt fiber through various experimental works in thermal and chemical environments, glass fiber and carbon fiber were compared and discussed. The tensile strength testing was used to investigate the corrosive resistance of basalt fiber, meanwhile, surface study by scanning electron microscopy and microanalysis with complementary X-ray diffraction analysis (SEM/EDS) was also used to ascertain the durability of basalt fiber. The basalt fiber showed better strength retention than the glass fiber at relatively high temperature. Its tensile strength increased when exposed at 300 °C for several hours, and still maintain about 70% of the initial strength at 400 °C, whereas that of the glass fiber decreased dramatically. The better stability of the basalt fiber was observed in hydrothermal and chemical environment. The tensile strength of the basalt fiber increased by 20% after the immersion in boiling water and remained well in acid solution, when it comes to glass fiber, the tensile strength decreased to some extent. Although the alkali resistance of basalt fiber was poor at the initial stage, it shows better resistance than the glass fiber after long time treatment.     

绿色韧性水泥基复合材料力学性能

为了研究绿色尾矿砂PVA纤维增强水泥基复合材料的韧性,参考国内外试验方法开展了立方体抗压、薄板拉伸和冲击韧性等力学性能试验研究.分析了纤维与基体的相互作用及增韧机理,讨论了纤维掺量和水胶比二元因素对增韧性能的影响.该研究获得了复合材料相应的强度和韧性指标,为高性能尾矿砂PVA纤维增强水泥基复合材料的制备和工程应用提供了参考.     

Mechanical Properties and Fracture Mechanism of a Glass Fiber Reinforced Polypropylene Composites

To study the effect of some parameters,such as,length and fraction of glass fiber (GF),and the fraction of maleic anhydride grafted polypropylene (PP-g-MAH),on the mechanical properties of glass fiber reinforced polypropylene (GF/PP) composites,tensile tests,bending tests and impact tests were conducted.Scanning electron microscope (SEM) was used to characterize the fracture mechanisms of the composites.The results show that,compared with 3 mm GF,9 mm GF can significantly improve the strength of the composite better.Addition of PP-g-MAH,a kind of grafting agent,into the PP-30% LGF composite can result in a better mechanical properties because of the strengthening of the bonding interface between the matrix and the fiber.When the mass fraction of GF is 30% and the PP-g-MAH fraction is 6%,the mechanical properties of the composite are the best.