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1.
通过物理共混的方式制备了发泡杜仲胶(EUG)/高密度聚乙烯(HDPE)形状记忆材料,探讨了共混比对其硫化特性、物理机械性能、发泡程度、结晶熔融行为和形状记忆性能的影响。结果表明,随着HDPE用量的增加,EUG/HDPE形状记忆材料的交联程度降低,100%定伸应力、300%定伸应力增大,但拉伸强度及扯断伸长率降低,物理机械性能与材料的交联结构、晶区、泡孔等微观结构密切相关;HDPE的加入使材料的发泡程度增大,EUG相的熔融温度及相对结晶度随着HDPE用量的增加而降低,HDPE的相对结晶度增大而熔融温度基本无变化;随着HDPE用量的增加,材料的热刺激响应温度Tr升高,形变回复速率Vr减小,热致形变回复率Rf无明显变化。  相似文献   

2.
采用超临界二氧化碳发泡技术制备了反式-1,4-聚异戊二烯/高全同聚丁烯-1(TPI/iPB-1)共混发泡材料,考察了TPI/iPB-1质量比对材料发泡性能及形状记忆性能的影响。结果表明,对于未交联TPI/iPB-1共混材料,随着iPB-1用量的增加,发泡倍率逐渐降低,发泡效果逐渐变差;二级形状记忆性能应变固定率逐渐下降,回复率逐渐升高,回复时间逐渐缩短。对于交联TPI/iPB-1共混材料,随着iPB-1用量的增加,发泡倍率逐渐减小,大孔逐渐消失,小孔数目也逐渐减少;交联的TPI/iPB-1发泡材料具备三级形状记忆效应,随着iPB-1用量的增加,材料的应变固定性变好,应变回复性降低。  相似文献   

3.
以可膨胀物理微球Expancel 920 DU 40为发泡剂,通过物理共混和化学交联的方式制备了发泡杜仲胶(EUG)/高密度聚乙烯(HDPE)形状记忆材料,从而实现了轻量化。采用扫描电镜、差示扫描量热法和万能材料试验机等对不同共混比的发泡EUG/HDPE复合材料的微观形貌、结晶熔融行为、物理机械性能和形状记忆行为等进行了研究。结果表明,随着HDPE用量的增加,发泡EUG/HDPE形状记忆材料的交联程度和拉伸强度降低,定伸应力增大,物理机械性能与材料内部的交联结构、晶区、泡孔等微观结构密切相关;HDPE的加入使复合材料的发泡程度增大,EUG相的熔融温度和相对结晶度随HDPE用量的增加而降低,HDPE的相对结晶度增大而熔融温度基本无变化;随HDPE用量的增加,复合材料的热刺激响应温度升高,形变回复速率减小,热致形变回复率无明显变化。  相似文献   

4.
研究了共混比对反式聚异戊二烯(TPI)/聚丁二酸丁二醇酯(PBS)共混物物理机械性能和形状记忆性能等的影响。结果表明,在TPI/PBS共混物中,随着PBS用量的增加,共混物的交联密度逐渐减小,物理机械性能下降,热刺激相应温度和形状恢复率整体也呈下降趋势。当TPI与PBS质量比为90/10时共混物的综合性能较为优异。增容剂CPE的加入可改善TPI与PBS两相的相容性,使共混物的物理机械性能和热致形状记忆性能得以有所提高。  相似文献   

5.
《塑料》2017,(2)
采用熔融共混的方法制备聚丙烯(PP)/反式-1,4-聚异戊二烯(TPI)共混材料,并加入过氧化二异丙苯(DCP)使其形成一定程度的交联结构,然后用超临界CO2方法对其进行发泡。通过差示扫描量热分析(DSC)对共混材料发泡前后的热性能进行了研究;通过扫描电子显微镜(SEM)等测试手段观测了发泡材料的泡孔结构。研究表明:交联PP/TPI发泡材料的发泡倍率、泡孔尺寸降低,泡孔密度增大。  相似文献   

6.
硅烷交联HDPE配方的二次正交回归设计(续后)   总被引:2,自引:0,他引:2  
采用两步法研制了硅烷交联高密度聚乙烯(HDPE)。利用二次正交回归设计探讨了交联温度、交联时间等5个因素对硅烷交联HDPE的拉伸强度、断裂伸长率及凝胶含量的影响,并对所得的回归方程进行了最优化,找出了各单项性能最优和综合性能最佳时所对应的参变量值,并通过实验进行了验证。  相似文献   

7.
《塑料》2017,(1)
采用熔融共混的方法制备聚丙烯(PP)/反式-1,4-聚异戊二烯(TPI)共混材料,然后用超临界CO_2对其进行发泡。通过差示扫描量热分析(DSC)、发泡倍率测试、扫描电子显微镜(SEM)等测试手段研究了共混材料发泡前后的性能变化。结果表明:PP/TPI共混材料可形成微孔泡沫结构;随着TPI含量增加,材料泡孔尺寸变大,泡孔壁变薄。  相似文献   

8.
采用反应性挤出法制备了硅烷交联聚丙烯/聚烯烃弹性体(PP/POE)共混材料。研究了过氧化二异丙苯(DCP)用量对硅烷交联PP/POE共混材料凝胶含量、热稳定性、结晶行为、耐溶剂性及力学性能的影响。结果表明:随着DCP用量的增加,硅烷交联PP/POE共混材料的凝胶含量、热稳定和耐溶剂性均逐渐提升。随着交联程度的增大,共混材料中PP相的结晶度逐渐减小。扫面电子显微镜(SEM)分析结果显示,硅烷交联反应能够改善PP和POE相之间的相容性。力学性能测试结果显示,相比于未改性PP/POE共混材料,硅烷交联PP/POE共混材料的各项性能均有不同程度的提升。  相似文献   

9.
《塑料科技》2016,(7):56-61
利用电子束对乙烯-醋酸乙烯共聚物(EVA)与丁腈橡胶(NBR)的共混物进行辐照交联,得到不同共混比例的EVA/NBR复合材料。考察了该复合材料的力学性能、交联度、耐油性、结晶性能及形状记忆性能,并讨论了辐照剂量和共混比例对材料性能的影响。结果表明:电子束辐照提高了EVA/NBR复合材料的力学性能和耐油性,同时降低了材料的结晶性能,这主要是由于辐照诱发了交联反应使材料内部产生了交联结构。通过控制交联度以及结晶相与NBR的比例,能够得到综合性能良好的耐油热收缩材料。  相似文献   

10.
通过电子束辐照研究了乙烯-甲基丙烯酸甲酯共聚物(EMMA)与三元乙丙橡胶(EPDM)不同共混比例材料的力学性能、硬度、交联度、结晶及形状记忆等,考察了辐照剂量和共混组分比例对材料性能的影响。结果表明,辐照提高了共混体系的力学性能和硬度,同时降低了结晶性能,这主要是由于辐照诱发了交联反应,使材料内部产生了交联结构。辐照交联为EMMA/EPDM共混物热收缩材料提供了形状回复的驱动力,但降低了形状固定率,通过控制交联度和结晶相所占比例,能够得到综合性能好的热收缩材料。当EMMA/EPDM(质量比)达到或高于3/7、辐照剂量控制在40~80 k Gy时,能够制备出满足基本要求的热收缩材料。  相似文献   

11.
A novel series of shape memory blends of trans‐1,4‐polyisoprene (TPI) and low‐density polyethylene (LDPE) were prepared using a simple physical blending method. The mechanical, thermal and shape memory properties of the blends were studied and schemes proposed to explain their dual and triple shape memory behaviors. It was found that the microstructures played an important role in the shape memory process. In TPI/LDPE blends, both the TPI crosslinking network and LDPE crystalline regions could work as fixed domains, while crystalline regions of LDPE or TPI could act as reversible domains. The shape memory behaviors were determined by the components of the fixed and reversible domains. When the blend ratio of TPI/LDPE was 50/50, the blends showed excellent dual and triple shape memory properties with both high shape fixity ratio and shape recovery ratio. © 2017 Society of Chemical Industry  相似文献   

12.
陈挺  张广成  刘铁民  项士新  缪桦 《塑料》2004,33(5):22-25
研究了利用具有较高形变回复能力的弹性体与HDPE共混,以改善纯HDPE材料较低的形状回复能力;以及共混体系形状回复性能的影响因素和材料的耐原油腐蚀性能;探讨了HDPE及共混体系形状回复机理。结果表明:HDPE(2480)/NBR15%的形状回复率由纯HDPE(2480)的81.3%提高到89.8%,并具有良好的耐高温原油腐蚀性能,可以满足穿插法修复原油输送管道的要求。弹性体的加入使体系形状回复能力提高,对穿插法修复旧管道具有重要的应用价值。  相似文献   

13.
形状记忆功能高分子材料的研究现状   总被引:16,自引:2,他引:14  
讨论了形状记忆功能高分子材料的类型和特点,概述了反式聚戊二烯、交联聚乙烯、聚降冰片烯及聚氨酯等形状记忆功能高分子材料的实验和理论研究进展。重点介绍了反式聚异 一烯的结构、特性、形状记忆功能的原理、配方、性能及其应用领域与前景。  相似文献   

14.
热固性环氧树脂形状记忆效应研究   总被引:2,自引:0,他引:2  
将新型的高分子固化剂与环氧树脂(EP)进行共混,经适度交联固化后制备出一种具有较低玻璃化转变温度(Tg)的无定型EP体系,并对该EP固化体系的力学性能、形状记忆特性和动态力学性能等进行了研究。结果表明:适度交联固化的EP体系具有良好的形状记忆特性,固化剂用量是影响该形状记忆体系综合性能的主要因素;其最大形变恢复率均为100%,形变恢复速率基本上随固化剂用量增加而增大,最大形变恢复速率为0.023 s-1;形变固定率随固化剂用量增加而减小,当w(固化剂)=37.5%或54.5%时,形变固定率为100%或96%。  相似文献   

15.
Shape memory materials are a type of smart material with potential applications in sensors, textiles, aerospace engineering and medical devices. In this study, we prepared Eucommia rubber and high density polyethylene (HDPE) composites with co‐continuous architecture by a simple physical blending method. The shape memory composites memorized two temporary shapes using different melting points of natural Eucommia rubber and HDPE with the addition of dicumyl peroxide (DCP). The architecture of Eucommia rubber/HDPE composites is critical to the materials' properties: each component forms a three‐dimensional percolating network and good properties of the two components may be synergically combined. Our results showed that the memory behavior of the composites was dependent on the degree of crystallinity in the composites. When the DCP was 1 phr, the physical and mechanical properties of the Eucommia rubber/HDPE composites improved and exhibited excellent shape memory behavior, with better values of the shape fixity ratio than of the shape recovery ratio. When DCP was 6 phr, the crystalline phase of Eucommia rubber in the composites was almost completely destroyed, which resulted in one temporary shape memory behavior of the composites. © 2016 Society of Chemical Industry  相似文献   

16.
辐照交联阻燃形状记忆标识套管材料是用于电线电缆和电子元器件标识领域的高分子形状记忆材料。本文选择合适的乙烯-醋酸乙烯酯(EVA)作为基体,十溴二苯乙烷、氧化锑和氢氧化镁作为复合阻燃剂,研究了辐照交联阻燃形状记忆标识套管材料的配方,通过混炼造粒、挤出成型、辐照交联、真空扩张和整平包装,获得了符合美军标AMS-DTL-23053和SAE-AS81531的形状记忆标识套管材料。  相似文献   

17.
根据扬子石化公司开发HDPE新牌号产品的生产经验,从分子量及分子量分布与树脂性能的关系、密度对HDPE性能的影响、HDPE的共聚改性、HDPE的共混改性、添加剂与HDPE改性等5个方面讨论了HDPE新牌号产品开发的方法。  相似文献   

18.
Abstract

Change in crystallization morphology of polypropylene (PP) on blending with high density polyethylene (HDPE), and on incorporation of cross-linking agent, trimethyl propane triacrylate (TMPTA), and nucleating agent, aluminium dibenzoate (DBS), was studied using differential scanning calorimetry (DSC), polarizing light microscopy (PLM), and small angle light scattering (SALS). In all, three blend systems: PP-HDPE, PP-HDPE-TMPTA, and PP-HDPE-DBS were developed. Analysis of crystallization exotherm, PLM, and SALS studies indicate that DBS is an effective nucleating agent for PPHDPE system and results in appreciable reduction in spherulite size and increase in percent crystallinity, while on cross-linking there is reduction in both percentage crystallinity and spherulite size. Improvement in overall mechanical properties is observed in all the systems studied. As it is desirable to work with PP having a high degree of crystallinity, low spherulite size and low melt flow index (MFI) for oriented film applications, PP-HDPE-DBS system with a low MFI grade HDPE is found to be most suitable.  相似文献   

19.
Shape memory behaviors of trans‐polyisoprene (TPI) segmented urethane copolymers were studied. Film specimens for cyclic loading tests were prepared from the polymer solution by casting, and tested at the loading temperature of 65°C. Results show that the recovery rates of the films depend on their TPI segment contents, while the fixity rate was measured to be close to 100% for each sample. The film containing 70% TPI segments was found to show a recovery rate of 85%. Two separated phases were clearly observed in the morphology of the films. The urethane segments were organized into spherical domains acting as physical cross‐links during the shape memory process. The continuous phase formed by the crystalline TPI segments serves as the reversible phase responsible for fixation of the temporary shape. The tensile and dynamic thermal properties of those films were also studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 879–885, 2006  相似文献   

20.
以反式聚异戊二烯(TPI)为基质,研究了纳米碳化硅用量对碳化硅/TPI形状记忆复合材料硫化特性、物理机械性能、热性能及形状记忆性能的影响。结果表明,随着碳化硅用量的增加,复合材料的焦烧时间和正硫化时间都逐渐缩短;拉伸强度呈现先增大后减小的趋势,硬度逐渐增大;结晶度逐渐降低,从纯TPI的16.5%下降至碳化硅用量20份(质量,下同)时的13.9%;碳化硅用量为10份时复合材料的单向形状记忆性能最好,而其双向形状记忆行为在应力为250 kPa时的形状回复率达到了最大值79.1%。  相似文献   

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