自由基引发剂对PLA/PBAT共混物结构与性能的影响

利用过氧化苯甲酰(BPO)与过氧化二异丙苯(DCP)作为自由基引发剂,通过三螺杆挤出机制备了原位增容聚乳酸/聚己二酸-对苯二甲酸丁二酯(PLA/PBAT)共混物。运用傅立叶红外光谱仪、扫描电子显微镜、差式扫描量热仪、热重分析仪和电子万能试验机等研究了BPO与DCP对PLA/PBAT共混物的结构、微观形貌、热学性能、以及力学性能等。结果表明,BPO与DCP降低了分散相的尺寸,改善了两相界面粘结强度,增加了两相的相容性; BPO与DCP能够大幅提高共混物的热稳定性;添加0. 1份DCP时,PLA/PBAT共混物冲击强度达到最大值9. 38 MPa。     

界面作用对PP/PA6共混体系相结构与力学性能的影响

研究了两种相容剂马来酸酐接枝聚丙烯(PP-g-MAH)、马来酸酐接枝乙烯-辛烯共聚物弹性体(POE-g-MAH)对聚丙烯/尼龙6(PP/PA6)共混体系力学性能的影响.通过扫描电子显微镜(SEM)、差示扫描量热仪(DSC)分析和力学性能测试,研究了相容剂POE-g-MAH和PP-g-MAH对PP/PA6共混物相容性、形态结构和力学性能的影响.研究结果表明:两种相容剂的加入都使PP/PA6体系的相容性增加,但PP-g-MAH的加入主要表现为增强效果,而POE-g-MAH的加入主要表现为增韧效果.     

马来酸酐接枝物对PE/PA6共混物相容性的影响

采用熔融共混法制备了PP/PA6/POE-g-MAH和PP/PA6/PP-g-MAH共混物。通过扫描电子显微镜(SEM)、差示扫描量热(DSC)仪分析和力学性能测试研究了增容剂POE-g-MAH和PP-g-MAH对PP/PA6共混物相容性、形态结构和宏观力学性能的影响。结果表明,在PP/PA6共混体系中分别加入POE-g-MAH和PP-g-MAH不仅能显著改善两相界面的相容性,减小分散相的粒径,而且能使共混物的力学性能显著提高。当增容剂的用量为5份时,PP/PA6共混物有较好的综合力学性能。POE-g-MAH和PP-g-MAH增容PP/PA6共混体系非等温结晶行为的研究表明,POE-g-MAH和PP-g-MAH均能促进PA6对PP基体的异相成核作用。     

马来酸酐接枝反式聚异戊二烯的结构与性能

以过氧化二异丙苯(DCP)和过氧化二苯甲酰(BPO)为引发剂,采用熔融法制备了马来酸酐(MAH)接枝反式聚异戊二烯(TPI)共聚物(TPI-g-MAH),通过傅里叶变换红外光谱仪、核磁共振波谱仪和差示扫描量热(DSC)仪对TPI-g-MAH进行了表征,探讨了接枝反应机理,研究了DCP和MAH用量对接枝产物TPI-g-MAH力学性能的影响。结果表明,以DCP、BPO作为引发剂,用熔融法制备的TPI-g-MAH均存在接枝现象,MAH主要与TPI中的α氢原子发生取代反应而接入TPI大分子链上,用DCP作为引发剂接枝率高、凝胶质量分数小。TPI-g-MAH的DSC谱图由双峰分布转向单峰分布,加入DCP引发剂得到的TPI-g-MAH比加入BPO引发剂得到的TPI-g-MAH的DSC谱图熔融峰窄、峰面积小。与纯TPI相比,TPI-g-MAH的拉伸强度下降,随着MAH和DCP用量的增加,TPI-g-MAH的拉伸强度下降明显。     

EPDM/NBR共混胶硫化体系的研究

研究了过氧化物DCP、DCP/S并用硫化体系及共交联剂ZDMA的加入对三元乙丙胶/丁腈胶(EPDM/NBR)共混胶性能的影响。研究表明:在过氧化物硫化体系中,随DCP用量的增加,共混胶综合性能先提高后降低,DCP用量为3份时性能达到最佳;DCP/S并用硫化体系中,随硫磺和促进剂加入量的增加,共混胶硫化速度提高,但综合力学性能降低;共交联剂ZDMA由0份增加至15份,共混胶力学性能显著增加,老化性能没有改善。     

反应性熔融共混改性聚乳酸柔韧性研究

采用反应性熔融共混的方法制备聚己二酸-1,2-丙二醇酯(PPA)增塑改性聚乳酸(PLA)材料,并加入4,4-二苯基甲烷二异氰酸酯(MDI)作为相容剂.通过扫描电子显微镜(SEM)、动态力学热分析(DMA)、差示扫描量热仪(DSC)及力学性能测试等手段研究了共混材料的相容性和力学性能.结果表明,在PPA含量低(10％)的情况下,其达不到增塑改性PLA的目的;而添加MDI能够改善两者之间的作用力和界面相容性,从而提高材料的断裂伸长率,并使共混材料由脆性断裂变成韧性断裂.     

聚乙烯/石蜡油共混体系动态流变行为和相容性

将分子量相差较大的两种聚乙烯(PE)分别与石蜡油(LP)组成共混体系,通过旋转流变仪、偏光显微镜(PLM)、差示扫描量热仪(DSC)和扫描电子显微镜(SEM)研究了温度和LP含量对共混体系动态流变行为的影响,并对两相共混体系的相容性及微孔结构进行了表征.结果表明,随着温度的升高和LP含量的增加,PE/LP共混体系的储能...     

Study on NBR/PP grafting crosslinking system

以MP(马来酸酐接枝聚丙烯)作为NBR/PP弹性体的增容体系,采用3种引发体系BPO为引发剂,DCP为引发剂和没有引发剂研究对接枝反应的影响。还对不同橡塑比及3种不同的硫化体系DCP体系,酚醛树脂体系及硫黄体系对NBR/PP共混体系的影响进行了探讨。通过DSC,TEM对产品的亚微观结构进行了验证。     

聚丁二酸丁二醇酯与聚乳酸共混型全生物降解材料的结构和性能研究

通过机械共混法,使聚丁二酸丁二醇酯(PBS)、聚乳酸(PLA)熔融共混,制备了一种完全生物降解塑料。用红外光谱(FTIR)法、DSC(DifferentialScanningCalorimetry)法、扫描电镜法(SEM)及力学测试等手段研究了不同组分配比情况下共混物的结构、热性能以及力学性能变化。并研究了聚丙撑碳酸亚丙酯(PPC)的加入对共混体系性能的影响。结果表明:随着PBS含量的增加,PBS/PLA共混体系的拉伸强度降低不多,而断裂伸长率显著提高。而PPC的加入能够提高共混体系的相容性并显著提高体系的韧性。     

E-MA-GMA增容剂对PPS/PA66共混体系性能的影响

研究了增容剂乙烯(E)-丙烯酸酯(MA)-甲基丙烯酸缩水甘油酯(GMA)共聚物(E-MA-GMA)对聚苯硫醚(PPS)/聚酰胺(PA)66共混体系的相容性、力学性能、热性能、流变性能的影响。结果表明,增容剂的加入,增加了共混体系的相容性,提高了共混物的力学性能;DSC结果表明,E-MA-GMA影响共混体系的结晶和熔融行为;流变性能测试结果表明,增容PPS/PA66共混体系是假塑性流体,E-MA-GMA用量增加,使共混体系的表观黏度增大。     

PLA/PBS共混物增黏改性的研究

采用熔融反应共混法,通过引入过氧化二苯甲酰(BPO),对聚乳酸/聚丁二酸丁二醇酯(PLA/PBS)进行增黏改性。研究了该PLA/PBS反应共混物的流变性能、凝胶分数、热性能、力学性能和断面微观形貌。结果表明:随着BPO用量的增加,PLA/PBS反应共混物的转矩和凝胶分数均增大;PLA/PBS反应共混物的结晶性和熔点(Tm)随着BPO用量的增加而降低,且出现熔融双峰,当BPO用量增至1 phr时,熔融双峰消失,PLA和PBS间的相容性显著改善;随着BPO用量的增加,PLA/PBS反应共混物的断裂伸长率、拉伸强度、冲击强度均有所提高,而玻璃化转变温度(Tg)先降后升,体系的内耗则逐渐降低。     

硅橡胶/顺丁橡胶/乙丙橡胶共混材料的研究

针对硅橡胶具有较高耐热性．但力学性能差；三元乙丙橡胶（EPDM）力学性能较好，但互粘性较差；顺丁橡胶（BR）弹性好．但加工性能堇的特点，提出了将硅橡胶、三元乙丙橡胶与顺丁橡胶共混的方法，制成共混材料；再通过测定样品的性能，确定共混的最佳配比。结果表明：BR与EPDM、硅橡胶相客性较好，可达到共硫化；硅橡胶／BR／EPDM质量比为20／30／50时，共混物的物理机械性能和老化性能较好；用过氧化二异丙苯（DCP）／硫磺作硫化剂要好于用硫磺、过氧化二苯甲酰（BPO）和硫磺／BPO硫化剂。试样的耐热老化性能、邵尔A型硬度和扯断伸长率较好，其中样品的综合性能具备了硅橡胶、顺丁橡胶和三元乙丙橡胶的优点。     

(E/VAC)-g-MAH对PP/PBT共混体系的增容改性

以过氧化苯甲酰(BPO)为引发剂,通过熔融接枝法在Brabender转矩流变仪中制得马来酸酐接枝(乙烯/乙酸乙烯酯)共聚物[(E/VAC)-g-MAH]。将该接枝物用于增容聚丙烯/聚对苯二甲酸丁二酯(PP/PBT)共混体系。结果表明,在(E/VAC)-g-MAH的作用下,PP/PBT共混物的力学性能得到提高,界面形貌得到改善,体系的相容性得到明显增强。     

Silica‐modified SBR/BR blends

The purpose of this article is that the silica‐modified SBR/BR blend replaces natural rubber (NR) in some application fields. The styrene‐butadiene rubber (SBR) and cis‐butadiene rubber (BR) blend was modified, in which silica filler was treated with the r‐Aminopropyltriethoxysilane (KH‐550) as a coupling agent, to improve mechanical and thermal properties, and compatibilities. The optimum formula and cure condition were determined by testing the properties of SBR/BR blend. The properties of NR and the silica‐modified SBR/BR blend were compared. The results show that the optimum formulawas 80/20 SBR/BR, 2.5 phr dicumyl peroxide (DCP), 45 phr silica and 2.5 mL KH‐550. The best cure condition was at 150°C for 25 min under 10 MPa. The mechanical and thermal properties of SBR/BR blend were obviously modified, in which the silica filler treated with KH‐550. The compatibility of SBR/BR blend with DCP was better than those with benzoyl peroxide (BPO) and DCP/BPO. The crosslinking bonds between modified silica and rubbers were proved by Fourier transform infrared analysis, and the compatibility of SBR and BR was proved by polarized light microscopy (PLM) analysis. The silica‐modified SBR/BR blend can substitute for NR in the specific application fields. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

用KH-550改性白炭黑增强SBR／BR并用胶研究

丁苯橡胶（SBR）与顺丁橡胶（BR）进行共混改性,加入交联剂改善两者的相容性,并通过加入硅烷偶联剂了一氨丙基三乙氧基硅烷（KH-550）对白炭黑进行改性,增加其力学性能。测定试样的性能并确定具有最佳性能时的配比及最佳工艺参数。实验结果表明：在SBR／BR并用胶质量比为80／20时力学性能和耐老化性能较好;得到了最佳硫化工艺参数：硫化温度150℃;压力10MPa;时间20min;加入硅烷偶联剂KH-550后。胶料的力学性能得到明显改善。当加入硅烷偶联剂KH-5502．5mL时性能最为优异;加入交联剂过氧化二异丙苯（DCP）、过氧化二苯甲酰（BP0）都增加了两者的相容性,当加入两种交联剂DCP与BPO的质量比为1／3时相容性最佳。通过对空白试样及共混物试样进行FT—IR谱图分析和偏光显微镜照片分析,前者证明了SBR和BR之间产生了新的交联键,而后者证明了相界面的相容性提高了,胶料的机械性能和热老化性能得到显著提高。     

HNBR/EPDM共混物结构与性能研究

分别采用过氧化物和硫给予体作交联剂,考察了不同共混比对氢化丁腈橡胶（ＨＮＢＲ）／ＥＰＤＭ共混物性能的影响,并能力ＤＳＣ和ＴＥＭ分析了共混物的相容性,对两胶的共硫化也作了初步探讨。结果表明,两种硫化体系硫化的共混胶扯断伸长率保持率均在６０％以上,都具有优异的耐热氧老化性能。随ＨＮＢＲ用量增大,共混物的定伸应力、拉伸强度和撕裂强度均提高,磨耗明显降低。ＨＮＢＲ和ＥＰＤＭ为不相容体系,但硫化仪曲线显示二     

硅橡胶／EPDM／ⅡR共混的研究

研究了硅橡胶/三元乙丙橡胶/丁基橡胶的共混技术与硫化体系。对增容剂、共混比例等对共混胶的力学性能的影响进行了探讨。KH570适宜于作为共混增容剂;共混胶宜于采用DCP硫化,也可以采用硫黄硫化,随着丁基橡胶含量的增加,其力学性能有大幅度提高,并出现最佳值点。     

乙烯基酯树脂固化条件及其复合材料的研究

研究了过氧化二苯甲酰(BPO)、过氧化二异丙苯(DCP)、过氧化苯甲酸叔丁酯(TBPB)3种固化剂对乙烯基酯树脂固化工艺的影响,并根据固化工艺制备出树脂浇铸体及其碳纤维复合材料。采用差示扫描量热(DSC)法研究了不同树脂固化体系的反应放热特性,采用扫描电镜(SEM)分析了浇注体的断面的表面形态。并对浇注体及复合材料进行了力学性能测试和热稳定性表征,结果表明制得的复合材料具有优良的力学性能和热稳定性。     

Investigation on two modification strategies for the reinforcement of biodegradable lignin/poly(lactic acid) blends

In this work, biodegradable lignin/poly(lactic acid) (PLA) blends were prepared with melting compounding method. Dicumyl peroxide (DCP) and maleic anhydride (MA)/biphenyl peroxide (BPO) were used for the modification of the polymer blends, respectively. Structure of the polymer blends was characterized with Fourier transformed infrared spectroscopy and field emission scanning electron microscopy. Mechanical properties of the samples were determined with universal test machine and dynamic mechanical analysis. Thermal behaviors and thermal stability of the blends were all characterized with a thermal gravimetric analysis/differential scanning calorimetry simultaneous thermal analyzer. Lignin reinforced the mechanical strength of the blends while the thermal stability was not improved. At low content, DCP and MA/BPO apparently enhanced the mechanical strength of lignin/PLA blends. However, excessive DCP led to decreased tensile strength and elongation at break. Both DCP and MA/BPO resulted in lower glass transition temperature and melting temperature of PLA in the blends, while the thermal stability of the polymer blends was poorer after modification.     

Tailoring morphology to improve the gas‐barrier properties of thermoplastic polyurethane/ethylene‐vinyl alcohol blends

The morphology and helium‐barrier properties of thermoplastic polyurethane (TPU)/ethylene‐vinyl alcohol (EVOH) blends with and without dicumyl peroxide (DCP) were investigated by melting blending. A lamellar dispersion of EVOH with good helium‐barrier properties was observed in the TPU matrix with DCP. The evolution of the morphology of the blends is mainly related to the variation of the viscosity ratio between the dispersed phase and the matrix phase. Compared with pure TPU, lamellar morphology increased the helium‐barrier properties of the TPU/EVOH (60/40) blend by as much as 10‐fold. We also explored the effects of composition, DCP content, and blending sequence on the morphology and helium‐barrier properties of the TPU/EVOH blends. The morphology of the blends ranged from a droplet‐matrix to a lamellar structure. We determined the optimum amount of DCP to improve the helium barrier of the blends. The helium‐barrier properties of the blends prepared by direct blending were superior to those of the blends prepared by two‐segment blending, and the blends prepared by direct blending exhibited a well‐developed lamellar morphology. We compared the permeability of the samples with the theoretical results to explain the relationship between morphology and helium‐barrier properties. POLYM. ENG. SCI., 56:922–931, 2016. © 2016 Society of Plastics Engineers