弹性体接枝马来酸酐对PP/PA6 的增容作用

以4种弹性体接枝马来酸酐(MAH)共聚物作为聚丙烯/聚酰胺6(PP/PA6)共混体系的增容剂,从界面相互作用、形态结构和力学性能等方面比较了它们的增容作用。乙烯-辛烯共聚物接枝马来酸酐(POE-g-MAH)和乙丙三元共聚物接枝MAH(EPDM-g-MAH)使PP与PA6两相间的界面相互作用增强,增容效果较好;POE-g-MAH为增容剂时,PA6粒子分布较均匀,粒径约为1μm。POE-g-MAH能明显改善PP/PA6共混体系的韧性和强度,具有良好的增容作用。当w(POE-g-MAH)为10%时,w(PA6)为60%的共混体系拉伸强度最高,达到53.4MPa;适当增加PA6用量,可明显改善共混体系的流动性。     

马来酸酐接枝天然橡胶对纤维素纤维增强天然橡胶复合材料的增容作用

在无引发剂的熔融状态下,利用剪切力将马来酸酐接枝于天然橡胶分子链上,并将马来酸酐接枝天然橡胶(MNR)作为增容剂添加到纤维素纤维增强天然橡胶复合材料中,研究其对复合材料性能的影响.结果表明,在熔融状态下利用剪切力能够发生自由基反应或Diels-Alder反应,将马来酸酐接枝于天然橡胶分子链上而制得MNR.添加了MNR的纤维增强天然橡胶硫化胶的物理机械性能,尤其是定伸强度比未添加MNR的硫化胶有明显提高,应力弛豫程度减小;扫描电镜分析也说明添加MNR使填料与橡胶基质之间有了更强的界面黏合力.     

马来酸酐化液体聚丁二烯对天然橡胶/芳纶短纤维复合材料性能的影响

研究马来酸酐化液体聚丁二烯(MLPB)对芳纶短纤维(SAF)补强天然橡胶(NR)复合材料性能的影响。结果表明:SAF和炭黑对NR的补强有协同作用,加入相容剂MLPB提高了橡胶基体与纤维的界面粘合性能,复合材料静态和动态力学性能明显提高;随着MLPB用量的增大,复合材料100%定伸应力增大,拉伸强度、拉断伸长率和撕裂强度在MLPB用量为4.5份时达到最大值。     

马来酸酐接枝天然橡胶的制备及应用研究

以过氧化二异丙苯(DCP)为引发剂,在转矩流变仪中以马来酸酐(MAH)单体对天然橡胶(NR)进行接枝改性。通过傅里叶变换红外光谱对接枝物进行了定性表征;采用化学滴定法测定了反应产物中MAH的接枝率和接枝效率。研究了MAH单体用量、DCP用量、反应温度、转子转速等因素对反应产物接枝率和接枝效率的影响,研究结果表明,以转矩流变仪作为反应器,NR为100份(质量份数,以下同此),MAH和DCP分别为5份、0.75份,温度为130℃,转子转速为50 r/min的条件下反应3min,产物接枝率和接枝效率较高,分别为1.45%和30.63%。将所制备的马来酸酐接枝天然橡胶(NR-g-MAH)应用于尼龙短纤维增强天然橡胶复合材料(NR/SF)体系中,可有效改善尼龙短纤维与NR基体间的界面结合。     

聚丙烯接枝马来酸酐增容聚酰胺6／聚丙烯体系吸湿性能及力学性能的研究

以聚丙烯接枝马来酸酐(PP-g-MAH)为相容剂，利用其与聚酰胺6(PA6)在共混过程中的反应增容作用，实现了与聚丙烯(PP)之间的相容性共混，改变其用量，制备了系列具有不同组成的PA6／PP合金，研究了不同组成合金材料的吸湿性能及其在干态和充分吸湿状态时的冲击强度和拉伸性能。结果表明，向PA6／PP合金体系中加入相容剂PP-g-MAH后，可以改善合金的相界面，形成相容性的合金结构，明显降低合金材料的吸湿量及吸湿速率，但进一步增大相容剂PP-g-MAH的用量时，只能明显降低合金材料吸湿过程初期的吸湿速率，不能进一步显著降低合金材料的吸湿量。在相容剂PP-g-MAH用量一定时，随着PA6／PP合金体系中PA6组分含量的提高，合金在干、湿态条件下的冲击强度、拉伸强度、断裂伸长率均呈近似线性变化。对于具有相同基本组成的合金，随着相容剂PP-g-MAFI用量的增加，材料在干、湿态条件下的拉伸强度均有提高，杨氏模量则在干态时有所提高，在湿态时影响不显著，在干、湿态时断裂伸长率以及冲击强度均没有产生显著影响。     

马来酸酐接枝聚合物对聚酰胺共混物的增容作用

由于马来酸酐很容易被熔融接枝到很多的高聚物,并且可以较好改善共混体系的相容性,目前受到了很高的重视。本文对马来酸酐接枝聚合物对聚酰胺共混物的增容作用进行了综述,同时介绍了笔者在这方面的工作     

马来酸酐接枝SEBS对尼龙6/液晶共聚酯共混物的增容作用

通过流变行为和ＤＳＣ研究,发现马来酸酐接枝ＳＥＢＳ能有效地增容尼龙６／液晶共聚酯共混物。     

马来酸酐酰化壳聚糖/天然橡胶复合材料的制备及其性能研究

采用胶乳共混法,分别以引发剂过氧化苯甲酰(BPO)、过二硫酸钾(KPS)、偶氮二异丁腈(AIBN)、硫黄体系(VS)为引发剂,制备马来酸酐酰化壳聚糖(MCS)/天然橡胶(NR)复合材料。试验结果表明:KPS和VS引发的MCS/NR复合材料凝胶较少;VS引发的MCS/NR复合材料的物理性能比过氧化物预硫化MCS/NR复合材料大幅提高;MCS/NR复合材料的亲水性、耐热性能和抗菌性能与NR相比明显提高,有望作为制备医用NR制品的材料。     

马来酸酐预处理炭黑对硫化天然橡胶动态力学性能的影响

用DMA研究了马来酸预处理炭黑对硫化天然橡胶动态力学性能的影响,结果表明,马来酸酐预处理炭黑有利于降代天然橡胶的滚动阻力。     

马来酸酐及其酯接枝mPE增容PA 6/mPE共混物的制备

采用水相悬浮法制备了马来酸酐接枝茂金属聚乙烯(mPE-g-MAH)、马来酸二丁酯接枝茂金属聚乙烯(mPE-g-DBM),并以其为聚酰胺(PA)6/茂金属聚乙烯(mPE)共混物的增容剂,分别制备了PA 6/mPE/mPE-g-MAH,PA 6/mPE/mPE-g-DBM三元共混物。随着mPE-g-MAH,mPE-g-DBM用量的增加,三元共混物中PA 6的γ晶型增多,α晶型减少,PA 6与mPE的相容性加强,使三元共混物的韧性,特别是低温韧性提高。尽管mPE-g-DBM的接枝率比mPE-g-MAH高,但由于后者中的酸酐基团比前者的酯基更易与PA 6中的氨基、亚氨基反应,因此,mPE-g-DBM的增容、增韧效果不如mPE-g-MAH。     

Compatibilization of poly(lactic acid)/epoxidized natural rubber blend with maleic anhydride

The objective of this work was to determine the compatibilization effect of different concentrations of maleic anhydride (MA) in poly(lactic acid) blended with epoxidized natural rubber (PLA/ENR). ENR-grafted MA [ENR-g-MA] was synthesized using four concentrations of MA: 0.15, 0.30, 0.45, and 0.60 phr. Using an internal mixer, binary (PLA/ENR, PLA/ENR-g-MA) and ternary (PLA/ENR/ENR-g-MA) polymer blends were prepared with a constant rubber content of 10 wt %. ENR impaired the mechanical properties of PLA, perhaps due to the relatively large size of the rubber particles. The compatibilization effect of MA was evaluated from the results of impact strength testing. ENR-g-MA was a toughening agent for PLA when the concentration of MA was in the range of 0.30–0.60 phr. MA increased miscibility between PLA and ENR. This effect was indicated in the blends by reductions in rubber particle size, the glass transition temperature of PLA, and the α-transition temperatures of PLA and ENR. In the binary polymer blends, the MA concentration in ENR-g-MA that produced the optimal mechanical properties of PLA was 0.60 phr. In the ternary blends, mechanical properties of PLA did not improve at any concentration of MA in ENR-g-MA. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48297.     

短切碳纤维对天然橡胶/顺丁橡胶复合材料性能的影响

以天然橡胶(NR)和顺丁橡胶(BR)为基料,以短切碳纤维(SCF)为添加剂,制备了SCF/NR/BR复合材料,考察了SCF用量对NR/BR的摩擦性能及力学性能的影响。结果表明,SCF可增强NR/BR基体的强度,增大其硬度。在NR/BR混合胶中加入15份SCF可以降低混合胶的摩擦系数,减少混合胶的磨损量,提高混合胶的耐磨性能。SCF增强的NR/BR在摩擦过程中发生了磨粒磨损和黏着磨损,形成了卷曲磨屑。     

Effects of fiber composition and graft‐copoly(ethylene/maleic anhydride) on thermoplastic natural rubber composites reinforced by aramid fiber

Thermoplastic natural rubber (TPNR) composites of natural rubber and high‐density polyethylene at a ratio of 70/30 were prepared by melt blending with aramid fibers using an internal mixer. The fiber loadings were varied from 0 to 30% for systems with and without graft‐copoly(ethylene/maleic anhydride) (PE‐g‐MA) as a compatibilizer to study the variation of mechanical and dynamic mechanical properties. The tensile strength, modulus, hardness, and storage modulus improved with fiber loadings for both systems. The interaction between the matrix and fiber had also improved with the addition of PE‐g‐MA. Nevertheless, different behavior was observed in tan δ peak. The tan δ peak decreased with the increment of Twaron composition in the system with PE‐g‐MA and increased in the system without PE‐g‐MA. The results showed the importance of PE‐g‐MA in the system in improving the mechanical properties of Twaron–TPNR composite. POLYM. COMPOS., 27:395–401, 2006. © 2006 Society of Plastics Engineers     

Esterification effect of maleic anhydride on swelling properties of natural fiber/high density polyethylene composites

The natural fibers (banana, hemp, and sisal) and high density polyethylene were taken for the preparation of natural fiber/polymer composites in different ratios of 40 : 60 and 45 : 55 (w/w). These fibers were esterified with maleic anhydride (MA) and the effect of esterification of MA was studied on swelling properties in terms of absorption of water, at ambient temperature, and steam. It was found that the steam penetrates more within lesserperiod of time than water at ambient temperature. Untreated fiber composites show more absorption of steam and water in comparison to MA‐treated fiber composites. The more absorption of water was found in hemp fiber composites and less in sisal fiber composites. Steam absorption in MA‐treated and untreated fiber composites are higher than the water absorption in respective fiber composites. The natural fiber/polymer composites containing low amount of fibers show less absorption of steam and water at ambient temperature than the composites containing more amount of fibers in respective fiber composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

天然短纤维增强橡胶复合材料的研究进展

介绍了短纤维的预处理方法,总结了短纤维在橡胶中的混合、分散及取向状态,综述了短纤维-橡胶复合材料在轮胎、胶带和胶管中的应用进展,并提出了复合材料的研究方向.     

废聚丙烯/废轮胎胶粉/废尼龙短纤维复合材料Ⅱ.工艺条件

采用反应挤出方法制备了废聚丙烯／废轮胎胶粉／废尼龙短纤维(WPP／GRT／WSF)复合材料,讨论了螺杆转速、机头温度对WPP／GRT／WSF复合材料力学性能的影响。结果表明,当螺杆转速为15r／min,机头温度为185～195℃时,WPP／GRT／WSF复合材料的力学性能达到最佳,拉伸强度为13．6MPa,冲击强度为25．2kJ／m^2。按照最佳配方和工艺挤出管材的拉伸强度为4,6MPa,冲击强度为5．4kJ／m^2,爆破压力为0．69MPa。