晶须改性聚丙烯

主要研究了碱式硫酸镁晶须对聚丙烯及PP／SBS共混体系性能的影响,并将它与其它几种无机填料增强PP的效果作了对比。实验结果表明：碱式硫酸镁晶须对PP有较好的增强增韧效果,最佳用量为30份左右。SBS能使PP的冲击强度大大提高。但PP／SBS晶须体系增强效果不佳。碱式硫酸镁晶须具有开发价值。     

硅灰石填充改性聚丙烯体系结构与性能的研究

采用机械共混的方法制备了聚丙烯(PP)/硅灰石共混体系,并对共混体系的拉伸强度、冲击强度、断口形貌进行了测试与分析。在共混体系中加入弹性体乙烯-醋酸乙烯共聚物(EVA)和苯乙烯-丁二烯-苯乙烯(SBS),以增加体系的韧性;添加马来酸酐(MAH),以提高组分间的界面结合力。结果表明:EVA对共混体系增韧效果不明显,SBS能够增加体系韧性,MAH能够提高体系强度;当硅灰石质量分数为30%,SBS和PP-g-MAH的质量分数均为15%时,体系的力学性能最佳。     

SBS和BR对PP增韧改性协同作用的研究

本文对PP/SBS、PP/BR、PP/SBS/BR和PP/SBS/BR/HDPE几种共混体系进行了研究。得到了这几种共混体系配比与物理机械性能和熔体表观粘度的关系。结果表明,SBS与BR并用增韧PP时,有着显著的协同效应。PP/SRS/BR三元共混物具有优良的抗冲性能和良好的成型工艺性。     

PP-HBP改性PP／PVO的流变行为

研究了聚丙烯接枝超支化聚（酰胺酯）（PPHBP）／PP／聚氯乙烯（PVC）共混体系的流变行为。讨论了PP-HBP用煮对PP／PVC共混体系流变行为的影响。结果表明，当PP／PVC共混体系中加入PPHBP不大于5份时，PP／PVC／PPHBP共混体系的表观粘度大于PP／PVc共混体系的；当加入PP—HBP大于5份时，PP／PVC／PP-HBP共混体系的表观粘度小于PP／PVC共混体系的；随着温度升高，PP／PVC和PP／PVC／PP—HBP共混体系表观粘度减小。     

SIS/SBS/PP共混改性的研究

研究了新型聚丙烯(PP)合金材料的配方、制备、工艺及性能。分别讨论了不同用量的三元乙丙橡胶 (EPDM)、苯乙烯与异戊二烯嵌段共聚物(SIS)及苯乙烯与丁二烯嵌段共聚物(SBS)与PP组成的二元和三元共混体系对材料力学性能的影响。结果表明:SIS为PP较好的增韧剂,PP／SIS/SBS三元共混体系具有较好的协同效应,在某种程度上可以代替EPDM改性PP,共混改性后拉伸强度、扯断伸长率等性能优良。     

高抗冲聚丙烯喷灌管材的研制

用SBS和纳米CaCO3对无规共聚聚丙烯进行改性,结果表明,SBS使PP的冲击强度明显提高,但拉伸强度等有所降低;将表面改性的纳米CaCO3填充于PP／SBS共混体系中,可有效地提高共混体系的冲击强度、拉伸强度等力学性能及其它性能,可满足喷灌管在不同区域使用的要求。     

超声功率对PP/EVA共混物性能及微观形貌影响

对乙烯-醋酸乙烯酯(EVA)增韧聚丙烯(PP)共混物在熔融挤出过程中施加一定超声功率,研究超声功率对PP/EVA共混体系微观形貌、力学性能及结晶性能的影响。结果表明:随着超声功率的增大,分散相EVA在PP基体中的尺寸逐渐减小,超声的加入提高了EVA在PP中的分散性;另外,随着超声功率的增大,PP/EVA共混体系的缺口冲击强度先增大后降低;超声的加入提高了共混体系的结晶度。     

蓄电池用共混改性PP的研制

以均聚PP为主要原料,共聚PP、HDPE、SBS为改性剂,用挤出共混法研制蓄电池用共混改性PP塑料。通过对原材料的选择和配方试验,确定了共混物的基本配方:均聚PP100份,共聚PP10～15份,HDPE5～10份,SBS 3～5份,抗氧剂和紫外线吸收剂0.4～0.6份,其它2～3份,所得多元共混物的冲击强度比纯PP提高7～9倍,其他性能无明显下降,完全满足了使用要求。     

ATBN/MP复合增容NBR/PP热塑性硫化胶

研究了端氨基液体丁腈橡胶(ATBN)和马来酸酐接枝聚丙烯(MP)对NBR／PP共混体系的增容效果。采用TEM,SEM,DSC分析了NBR／PP共混体系的相态结构及其PP的结晶行为。结果表明,ATBN／MP是NBR／PP共混体系较理想的增容剂,当ATBN用量为5份,MP为10份时,增容效果最佳;增容剂存在一个临界胶束浓度(CMC),当增容剂浓度大于CMC时,增客剂的增容作用变差。增容良好的NBR／PP共混体系经过动态硫化后,可制备相态结构精细、性能优异的NBR／PP热塑性硫化胶;界面结合加强后,其流动性能略有下降。     

PP/EVA/沸石共混体系流变性能研究

采用3211型毛细管流变仪，研究230℃下乙烯－醋酸乙烯共聚物（EVA）单一体系及聚丙烯（PP）／EVA／沸石共混体系的表观粘度（ηa）和EVA的用量、EVA中醋酸乙烯酯（VA）含量、不同性质偶联剂改性沸石粉体等的相互影响规律。结果表明：对于纯EVA体系而言，熔体的ηa随共聚体系中VA含量的增加而增加，且均高于本研究所用PP熔体的ηa；其变化趋势同VA含量没有明显的线性关系，同熔体流动指数测试结果有相同的趋势。在PP／EVA沸石共混体系中，共混溶体的ηa均高于PP／沸石共混体系。对沸石表面采用极性化改性，所得共混溶体的ηa有所降低，证明采用不同偶联剂对粉体表面改性可以导致共混体系中不同结构的形成。     

不同增韧体系阻燃聚丙烯的制备和性能研究

通过高温预混制备了膨胀型阻燃剂(IFR),以马来酸酐接枝聚丙烯(PP-g-MAH)为增容剂,选用SBS、EVA、CPE、MBS分别对PP进行增韧改性,采用熔融插层法制备了阻燃聚丙烯(FRPP)。用TGA、LOI、SEM和力学性能测试等研究了不同种类的增韧剂对阻燃PP的热稳定性、阻燃性、力学性能的影响。结果表明:SBS的加入使阻燃PP的缺口冲击强度显著提高;IFR的加入,使得体系的极限氧指数普遍升高,其中EVA和CPE的极限氧指数达到32和30;综合材料的性能,选用SBS作为阻燃PP的增韧剂,所制得的阻燃PP的各性能优良。     

Morphological and mechanical properties of polypropylene [PP]/poly(ethylene vinyl acetate) [EVA] blends. II: Polypropylene‐(ethylene‐propylene) heterophasic copolymer [PP‐EP]/EVA systems

Morphological characteristics and mechanical properties of PP‐EP/EVA blends were studied and compared to those of PP/EVA previously reported. For the PPEP/EVA blends, interfacial interactions in amorphous zones, which were associated with shifts in T_g, were well defined compared to those of PP/EVA blends, although the nature of crystalline zones was similar for both systems. At EVA concentrations up to 20%, the elongation at break and impact strength slightly increased in both systems. However, PP‐EP/EVA displayed higher values of these properties compared with PP/EVA. At high EVA concentrations (above 20%), the indicated properties were enhanced in both polymeric systems, and the same proportional behavior was maintained. The decrease in tensile strength of PP‐EP/EVA was not as marked as in PP/EVA with the addition of EVA, and it remained below PP/EVA at high EVA concentrations. The improvement in properties of PP‐EP/EVA was attributed to favorable interactions between the ethylene groups contained in both copolymers. These interactions rendered a high degree of compatibility between the PP‐EP and EVA components.     

BR/EVA/HIPS TPV的制备和性能研究

采用苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)改善BR/乙烯-乙酸乙烯酯共聚物(EVA)/高抗冲聚苯乙烯(HIPS)共混物的界面相容性,通过动态硫化法制备BR/EVA/HIPS TPV,并对其性能进行研究.结果表明:未加入SBS的BR/EVA/HIPS共混物未表现出橡胶类弹性体特征,而加入适量SBS的共混物表现出典型橡胶类弹性体特征;当SBS用量为8～12份时,BR/EVA/HIPS TPV的综合物理性能较好,拉伸断面平滑,界面相容性良好.     

PET/EVA/PP ternary blends: An investigation of extended morphological properties

In this study, the effects of different parameters on the morphological properties of ternary blends were investigated. Therefore two systems (PET/H‐EVA/PP and PET/L ‐EVA/PP, H‐EVA and L ‐EVA are high and low viscosity, respectively) were prepared by melt mixing process. In all of the blends, poly (ethylene terephthalate) (PET) as the major phase‐ with poly propylene (PP) and two grades of poly (ethyl‐stat‐vinylacetate) (EVA) with different viscosities and subsequently different interfacial interactions was blended. Theoretical models predicted positive spreading coefficient for two grades of EVA and lower free energy for the samples consisting of EVA and PP as the shell and the core phases respectively. With changing core shell ratio, droplet size of samples containing L ‐EVA and H‐EVA increased and decreased, respectively. Subinclusion of shell into the core was observed in some blended samples. In systems containing H‐EVA, by thickening the shell phase; multi core morphology was observed which would be related to the coalescence phenomenon inter the droplets. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of heterophasic or random PP copolymer on the compatibility mechanism between EVA and PP copolymers

Compatibility mechanisms between EVA and PP copolymers (C‐PP) blends have been studied as a function of the type of copolymer, using a heterophasic PP copolymer (PP‐EP) and a random PP copolymer (PP‐r‐EP), with similar ethylene content. The morphology and thermal and mechanical properties of PP/EVA blends with different levels of EVA containing 28% vinyl acetate (VA) were determined. The obtained results indicated compatibility for both systems showing interactions at the amorphous interfaces; however, this interaction was higher for the PP‐r‐EP/EVA, which showed a single glass transition temperature and changes in the PP crystalline fraction (changes in the fusion temperature and in the diffraction patterns). The evolution of the morphology from isolated spherical domains (20% EVA) to elongated shapes (40% EVA) was related to the observed changes in thermal and mechanical properties. The impact strength and deformation properties showed significant improvement with increasing EVA content above 40% where the highest values of elongation for the PP‐r‐EPand of impact strength for the PP‐EP were obtained. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

动态硫化BR/EVA/SBS/HIPS热塑性弹性体的增强研究

采用动态硫化法制备了顺丁橡胶(BR)/乙烯-醋酸乙烯共聚物(EVA)/苯乙烯-丁二烯-苯乙烯共聚物(SBS)/高抗冲聚苯乙烯(HIPS)热塑性弹性体(TPE),通过在BR中充填炭黑的方式对复合体系进行增强,对其力学性能及断面微观结构进行了研究。结果表明,对于动态硫化BR/EVA/SBS/HIPS共混型TPE,当BR相中炭黑填充量在0~80phr的范围内,其动态硫化产物均表现出TPE的特征;随着炭黑用量的提高,复合体系的拉伸强度、撕裂强度、邵氏硬度趋于显著提高,断裂伸长率趋于下降,而扯断永久形变则趋于不变;未填充炭黑TPE的拉伸断面上两相界面结合良好;炭黑填充后的TPE的断面起伏较大但平滑,表明弹性较强。     

PP／EVA共混物中PP结晶行为及对性能的影响

借助ＤＳＣ和ＷＡＸＤ方法研究聚丙烯／乙烯－乙酸乙烯酯共聚物（ＰＰ／ＥＶＡ）共混体系的结晶行为，测定了共混物中ＰＰ的晶胞参数，结果表明，ＰＰ／ＥＶＡ体系中ＰＰ基体的晶胞参数以及结晶性能不受ＥＶＡ的影响：ＰＰ与ＥＶＡ两相没有形成共结晶，共混物中冲击性能的提高主要受ＥＶＡ含量及其微观形态结构的影响，而与ＰＰ结晶性能基本无关。     

PP/EVA共混物的动态硫化研究

研究了动态硫化对聚丙烯/乙烯-醋酸乙烯酯共聚物(PP/EVA)共混物的性能和结构的影响。结果表明:动态硫化使PP/EVA共混物的力学性能(尤其是韧性)获得显著提高;通过对交联剂BIPB用量和助硫化剂S用量的合理控制可制得综合性能优异的PP/EVA动态硫化共混物;动态硫化可细化分散于PP基体中的EVA颗粒粒径,改善EVA的分散效果。最终制得的抗冲PP料主要性能均达到或超过国外同类产品水平。     

Radiation effects on poly(propylene) (PP)/ethylene–vinyl acetate copolymer (EVA) blends

Radiation effects on poly(propylene)/ethylene–vinyl acetate copolymer (PP/EVA) blends are discussed. Increasing the EVA content enhanced the crosslinking effect of radiation in PP/EVA blends. This effect was significant when the EVA content was ≥50% in PP/EVA blends that were exposed to γ‐ray irradiation in air. This phenomenon is discussed in relation to the compatibility, morphology, and thermal properties of PP/EVA blends. The results indicate that the effect is dependent on the compatibility, the increase in the amorphous region content, and the EVA content in PP/EVA blends. The possible mechanism of radiation crosslinking or degradation in irradiated PP/EVA blends was studied quantitatively by a novel method, a “step analysis” process, and thermal gravimetric analysis. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3420–3424, 2002