动态光交联法制备PP/EPDM热塑性弹性体的力学及热性能

采用动态光交联法制备了PP/EPDM热塑性弹性体。动态力学热分析(DM TA)和扫描电子显微镜(SEM)及力学性能测试表明:动态光交联能明显提高PP与EPDM间的相容性,从而显著提高PP/EPDM热塑性弹性体的拉伸性能和缺口冲击强度。并结合DM TA、差热扫描量热仪(DSC)等手段,证实了动态光交联过程中产生了少量的接枝共聚物PP-g-EPDM。     

嵌段共聚物对PPO／PP共混物的增容作用

研究表明苯乙烯－乙烯／丙烯嵌段共聚物及其混合顺序对聚／聚丙烯共混物形态和性能有一定影响。ＰＰＯ／ＰＰ共混物加入增容剂后，分散相颗粒变得精细均匀，缺口冲击强度大大提高。文中计算了ＳＥＰ／ＰＰＯ及ＳＥＰ／ＰＰ共混物的相互作用能密度Ｂ，计算表明，ＥＰ体积分数高的ＳＥＰ和ＰＰＯ的亲和力比ＳＥＰ与ＰＰ的亲和力小，因此当ＳＥＰ先与ＰＰＯ预混合，然后与ＰＰ混合，ＳＥＰ易于迁移到两相界面，降低了界面张力，减小了分     

PP-g-(GMA-co-St)增容PC/PP共混体系的形态与性能

运用分级注入方法制备了不同配比的PC/PP-g-(GMA-co-St)/PP共混物。通过力学性能测试、扫描电子显微镜观察、高压毛细管流变测试等方法考察了增容剂PP-g-(GMA-co-St)对PC/PP共混体系的形态与性能的影响。PP-g-(GMA-co-St)的加入提高了两相界面结合力,降低了分散相粒子尺寸,有效地改善了共混体系的相容性;同时PC/PP-g-(GMA-co-St)/PP体系的拉伸性能得到显著的提高,体系表观黏度提高,对剪切应力的敏感性降低。     

增容作用和动态固化对聚丙烯/环氧树脂共混物形态结构的影响

研究了增容作用和动态固化对聚丙烯(PP)/环氧树脂(EP)共混物形态结构的影响。实验结果表明,PP/EP共混物是不相容共混体系,当环氧树脂含量小于50%时,共混物中环氧树脂以分散相存在,PP为连续相。反之,则共混物的相态发生相反转,即环氧树脂为连续相,PP为分散相。加入马来酸酐接枝聚丙烯(M AH-g-PP)促进环氧树脂与PP的相容性,使得分散相的颗粒明显变小。与PP/EP和PP/M AH-g-PP/EP共混物不同,当环氧树脂含量大于50%时,动态固化PP/EP和PP/M AH-g-PP/EP共混物仍是环氧树脂分散相和PP连续相结构,未出现相反转。对于相同含量环氧树脂的共混物,动态固化PP/M AH-g-PP/EP共混物中环氧树脂分散相尺寸明显小于动态固化PP/EP共混物中环氧树脂分散相尺寸。     

Grafting effects of polypropylene/polyethylene blends with maleic anhydride on the properties of the resulting wood-plastic composites

In the presented study, polypropylene (PP) and high density polyethylene (PE) were blended at the ratios of 80/20 and 20/80 to simulate recycled waste thermoplastic mixtures. The effects of in situ grafting of PP/PE blends with maleic anhydride through the extruder on the mechanical and rheological properties of resulting wood/plastic composites were investigated. Different ratios of PP and PE in the blends created distinct properties in the resulting composites. Grafting of PP and PE blends improved the tensile and flexure properties of the resulting composites. The composites exhibited a reduced water uptake and resultant dimensional swelling due to grafting with maleic anhydride. Grafting of the blends also considerably improved the interfacial bonding and enhanced the dispersion of wood in the matrix, as evidenced by rheological analysis and scanning electron microscopy.     

聚丙烯／丙烯－辛烯共聚物共混体系的研究

利用扫描电镜、差热扫描量热计和动态粘弹谱仪等手段研究了聚丙烯／丙烯－辛烯共聚物共混体系的相容性及结晶和转变性能等。研究结果表明，该共混体系是完全相容的体系，该共混物的低温韧性优于聚丙烯。     

DCP用量对PP／EPDM共混物性能和形态的影响

用动态硫化法制备的PP／EPDM共混型热塑性弹性体的性能明显优于直接共混型PP／EPDM热塑性弹性体,这是由于模量低的EPDM柔性长链经化学交联后,强化对PP的增韧效果,而交联后又被扯断细化的EPDM的颗粒,改变了因EPDM相互缠结所导致的熔融粘度大,加工性能差的缺陷。制备PP／EPDM热塑性弹性体的关键是动态硫化,由于PP／EPDM共混物的动态硫化是一个融物理共混、化学引发交联和剪切细化分散为一体的复杂过程,材料的性能除决定于组成、组分性能和化学交联体系外,还强烈依赖于所采用的共混工艺方式及其条件。本章采用过氧化二异丙苯（DCP）作为硫化剂,研究了过氧化物用量对动态硫化PP（K8303）／EPDM共混物性能和形态的影响。     

PP/PA1010共混物的形态结构及力学性能的研究

利用红外光谱、扫描电子显微镜和力学测试等方法, 甲基丙烯酸环氧丙酯熔融接枝聚丙烯ＰＰ－ｇ－ＧＭＡ对不同组成的ＰＰ／ＰＡ１０１０共混物形态结构和力学性能的影响。     

Toughening of polyamide 6 with β-nucleated thermoplastic vulcanizates based on polypropylene/ethylene–propylene–diene rubber grafted with maleic anhydride blends

The toughening of polyamide 6 (PA 6) with β-nucleated thermoplastic vulcanizates (TPVs) based on polypropylene (PP)/ethylene–propylene–diene rubber grafted with maleic anhydride (EPDM-g-MAH) blends was studied. A series of TPVs without and with different dosage of β-nucleating agent (β-NA) were prepared and used to toughen PA 6 at the same proportion. Differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) measurements showed that β crystals of PP were effectively induced in the TPVs. The PA 6 blends toughened with β-nucleated TPVs (β-TPVs) exhibit significantly enhanced toughness, balanced mechanical properties and thermal properties compared with PA 6 toughened by TPV without β-NA or only by EPDM-g-MAH. Phase morphologies of the blends characterized by scanning electron microscopy (SEM) showed that better interfacial adhesion caused by the migration of β-NA from PP to PA 6/PP interface and PP/EPDM-g-MAH interface gives rise to more uniform dispersion and smaller size of the dispersed phase; moreover, the core–shell structure comprised of rubber particles enveloped by PP on the surface, brings about easier and stronger interference of the stress field of EPDM phase.     

Compatibilizing effect of maleated polypropylene on the mechanical properties of injection molded polypropylene/polyamide 6/functionalized-TiO2 nanocomposites

TiO₂ nanoparticles were pretreated with excessive toluene-2,4-diisocyanate to synthesize TDI-functionalized TiO₂ (TiO₂-NCO), and then the polypropylene/polyamide 6/(PP/PA6, 70/30 wt%) blends containing 3 phr of the TDI-functionalized TiO₂ were prepared using twin-screw extruder followed by injection molding. Maleated polypropylene (PP-g-MAH) was used to compatibilize the blends. The mechanical properties of PP/PA6 blends based nanocomposites were studied through tensile and flexural tests. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to assess the fracture surface morphology and the dispersion of the TDI-functionalized TiO₂, respectively. The dynamic mechanical properties of PP/PA6 based nanocomposites were analyzed by using dynamic mechanical thermal analyzer (DMTA). The strength and stiffness of the PP/PA6 compounds were improved significantly in the presence of PP-g-MAH. This has been attributed to the synergistic effect of TDI-functionalized TiO₂ and PP-g-MAH. The PP-g-MAH compatibilized PP/PA6 compounds showed a homogeneous morphology supporting the compatibility improvement between PP, PA6 and TDI-functionalized TiO₂. TEM results revealed that the TDI-functionalized TiO₂ nanoparticles were exfoliated and uniformly dispersed in blends matrix. Possible chemical interactions between PP, PA6, TDI-functionalized TiO₂ and PP-g-MAH were proposed based on the experimental work.     

PP固相接枝物增容PP/PA6共混物的界面相互作用和力学性能

研究了PP固相接枝混合三单体（gPP)增容PP／PA6共混物的界面相互作用和力学性能，结果表明，该gPP是PP／PA6共混物的有效增容剂，在PP／PA6共混物的所有组成范围内，加入少量的gPP均可达到良好的增容效果，能显著提高共混物的力学性能，固相接枝物对PP／PA6共混体系的增容效果与固相接枝物用量及制备固相接枝物时第三单体的用量相关，通过Molau实验，傅里叶红外谱换光谱测试，抽提实验等证实；gPP的加入使得PP／PA6共混物在共混过程中就地形成了两相之间的增容剂PP－gPA6，增强了两相界面间的相互作用，gPP用量越大，PP－g-PA6的生成量越大，两相间的界面相互作用越强     

尼龙11/POE共混物的形态与力学性能

采用动态力学分析(DMTA)和扫描电镜(SEM)等方法研究了相容剂乙烯辛烯共聚物接枝马来酸酐聚合物(POE-g-MAH)对尼龙11(PA11)共混体系力学性能及共混物形态的影响。结果表明,混合弹性体中m(POE-g-MAH)/m(POE)=2∶1时,PA11共混物的缺口冲击强度达到81.2 kJ/m2;共混物缺口冲击强度对MAH接枝率敏感;加入混合弹性体,共混体系分子间的作用力增大,损耗峰向高温方向移动,Tg升高;PA11与POE各个共混体系的β松弛峰高显著低于纯PA11的,加入POE和POE-g-MAH可有效降低PA11的吸水性;POE-g-MAH可显著改善PA11/POE共混材料的相容性,使分散相尺寸减小,分布均匀,且材料缺口冲击强度显著增大。     

Effect of polyphosphazene and modified carbon nanotubes on the morphological and thermo-mechanical properties of polyphenylene sulfide and liquid crystalline polymer blend system

Ternary blends of polyphenylene sulfide (PPS) and liquid crystalline polymer (LCP) with either polyphosphazene, unmodified multiwall carbon nanotubes (MWCNTs) or SiC-coated MWCNTs, were prepared by melt blending. While polyphosphazene improved the compatibility between the PPS and LCP, unmodified MWCNTs promoted LCP domain deformation, from spherical to ellipsoidal. Long LCP fibers were formed in presence of SiC-coated MWCNTs due to the bridging effect of modified MWCNTs at the interface of PPS and LCP. This bridging effect was confirmed by field emission scanning electron microscopy (FESEM). The better dispersion of SiC-coated MWCNTs was confirmed by both FESEM and transmission electron microscopy analysis. The superior mechanical properties of SiC-coated MWCNTs added blend system can be attributed to the fibrillation of LCP and better dispersion of SiC-coated MWCNTs. Polyphosphazene containing blend system showed lowest thermal stability while blend with SiC-coated MWCNTs was found to be highest, among all the blend systems.     

RSMA增容PA6/PP共混物的形态结构与增容机理

采用ＲＳＭＡ为增容剂制备了ＰＡ６／ＰＰ共混物,研究了ＲＳＭＡ增容ＰＡ６／ＰＰ共混物的形态结构和热行为以及晶态结构,并探讨ＲＳＭＡ增容ＰＡ６／ＰＰ共混物的增容机理结果表明,ＰＡ６／ＰＰ共混物为热力不相容的海岛型两相结构,ＲＳＭＡ的加入改善ＢＰＡ６与ＰＰ相间的相容性,使两相分均匀,分散度提高。ＲＳＭＡ对ＰＡ／ＰＰ共混物的增容机理可用界面－分散相复合模型描述。     

废弃LDPE / PA6 / LLDPE 复合膜回收再生的研究

以废弃缓冲空气垫( LDPE/ PA6/ LLDPE) 复合薄膜为基体材料,低密度聚乙烯接枝马来酸酐( LDPE-g-MAH)为相容剂,通过混合、挤出、吹塑工艺制备了LDPE/ PA6/ LLDPE 再生共混材料,并对相容剂添加量(质量分数)分别为3%,8%,12%,16%时再生共混材料的力学性能、阻隔性能、熔体流动性能和微观形态结构进行了测试与分析。结果表明,LDPE-g-MAH 的加入明显改善了尼龙和聚乙烯共混两相的界面相容性;相容剂添加量为3% ~8%的再生共混材料的阻隔性能较好,相容剂添加量为8% ~16% 的共混合金的力学性能得到了显著提高。     

异氰酸酯接枝改性淀粉/聚碳酸亚丙酯共混物及性能

为提高淀粉(Starch)与聚碳酸亚丙酯(PPC)的界面作用力,在淀粉颗粒与PPC复合时加入二苯基甲烷二异氰酸酯(MDI),进行反应性共混改性,通过FTIR、DSC、TGA、SEM、拉伸测试等手段对共混物进行表征,验证了接枝作用的发生,同时讨论了在熔融状态下,MDI对共混物接枝改性的作用效果.结果表明:有PPC大分子接枝到淀粉颗粒表面上.正是接枝的PPC在两相间充当兼容剂,提高了其相容性,增强了PPC相与淀粉颗粒之间的界面粘接力,使得形态结构稳定化,从而使得力学性能和热稳定性得到有效改善.     

Effect of EVOH on the morphology,mechanical and barrier properties of PA6/POE-g-MAH/EVOH ternary blends

Polyamide 6 (PA6)/maleated poly(ethylene-1-octene) (POE-g-MAH) blends with various ethylene–vinyl alcohol (EVOH) concentrations were prepared via melt-blending. The morphology, mechanical and barrier properties of the blends were investigated in terms of scanning electron microscope (SEM), impact/tensile testing, dynamic mechanical analysis (DMA) and oil absorption rate. The SEM images indicated that the compatibility between PA6 and POE-g-MAH was improved significantly after the incorporation of EVOH. The toughness of blends was correlated with the morphology of the POE-g-MAH and EVOH dispersion phase. It has also demonstrated that the incorporation of EVOH increased evidently the tensile strength, storage modulus and barrier properties, which were contributed to the strong interactions formed through the reaction among PA 6, POE-g-MAH and EVOH.     

Control of the structure and properties of barium sulphate-filled blends of polypropylene and ethylene propylene copolymers

The structure and properties of polypropylene (PP) and ethylene propylene copolymer (EPR) blends filled with BaSO₄ have been investigated. The aspect of structure control concerned was the separate dispersion of filler and rubber in the PP matrix or encapsulation of the filler in the rubber phase. The former structure prevails in the PP/EPR/BaSO₄ systems, and addition of maleic anhydride-grafted polypropylene (MAPP) enhances the adhesion between the PP matrix and the filler. Encapsulation of the filler particles into the elastomer takes place when maleated EPR-rubber (EPMA) is used, and the encapsulated structure prevails even under the severe shearing conditions of injection molding. The improved matrix/filler adhesion resulted in increased yield stress and tensile strength, but decreased impact resistance. The particle size of the filler proved to be a crucial factor; below a certain particle size aggregation becomes a dominating factor. Extensive aggregation leads to the deterioration of all mechanical properties, especially to decreased impact strength.     

氧化石墨烯对聚丙烯/尼龙6两组分聚合物的增容作用

采用改进的Hummers法制备氧化石墨烯,然后将其与聚丙烯/尼龙6(PP/PA6)两组分聚合物进行熔融共混制备聚丙烯/尼龙6/氧化石墨烯纳米复合材料。通过拉伸强度测试、差示扫描量热测试并结合扫描电子显微镜对尼龙6分散相尺寸大小观察表明,由于氧化石墨烯表面环氧官能团与尼龙6中端氨基能发生化学反应,有效提高了各组分之间的界面相互作用;少量的氧化石墨烯使尼龙6分散相尺寸大幅度减小,并使复合材料拉伸强度大幅度提高,由此表明石墨烯对热力学不相容聚丙烯/尼龙6两组分聚合物具有良好的增容作用。     

马来酸酐接枝聚丙烯在纸粉填充聚丙烯体系中偶联作用的研究

研究了马来酸酐接枝聚丙烯（ＭＡＰＰ）对纸粉（ＰＦ）／聚丙烯（ＰＰ）复合材料性能的影响，并对其偶联机理进行了探讨。力学测试和扫描电镜（ＳＥＭ）结果表明，ＭＡＰＰ是本体系有效的偶联剂；质量分析实验证明ＭＡＰＰ与纸粉发生了化学反应，同时差示扫描量热分析（ＤＳＣ）和广角Ｘ射线衍射实验（ＷＡＸＤ）证明ＭＡＰＰ的ＰＰ链段可与ＰＰ基体形成共结晶。