聚酰亚胺

Silver localization on polyimide using microcontact printing and electroless metallization

ty10086 提交于 周四, 08/26/2021 - 13:33
Abstract(#br)Silver localization is obtained on polyimide Kapton ® HN (PI) in step by step processes combining surface treatments (chemical and plasma), microcontact printing (μCP) and electroless metal deposition. There processes are developed in order to obtain silver patterns onto flexible polymer surfaces at the micro and sub-micro scale. Patterns of silver dots or, at the opposite, of holes in silver layer, were obtained using the same PDMS polydimethylsiloxane (PDMS) stamp (positive/negative technology). Processes are based on the same first step, i.e.

Crosslinkable TEGMC asymmetric hollow fiber membranes for aggressive sour gas separations

ty10086 提交于 周四, 08/26/2021 - 13:17
Abstract(#br)Hollow fiber membranes were prepared from TEGMC ( T ri E thylene G lycol M onoesterified C rosslinkable) 6FDA-DAM:DABA (3:2) polyimide and shown to retain their stability and permselectivity under aggressive sour gas feed conditions. The H 2 S/CH 4 and CO 2 /CH 4 permselectivities of these cross-linked fibers exceeded those of dense-film membranes, which is attributed to polymer-chain alignment induced during the spinning process.

Effect of in situ-formed polydimethylsiloxane on the properties of polyimide hybrids

ty10086 提交于 周四, 08/26/2021 - 12:57
Abstract\n\t\t\t\t\n\t\t\t\t\tPolyimide-polydimethylsiloxane (PI-PDMS) hybrids were synthesized by combining an in situ sol–gel reaction of diethoxydimethylsilane (DEDMS) and imidization of poly(amide acid) (PAA) prepared from pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA). Transparent hybrid films were obtained with up to 3\n\t\t\t\t\t\twt.% PDMS content corresponding to the relatively small domain size of PDMS as confirmed by scanning electron microscopy.

Characterization and gas transport properties of UV-irradiated polydimethylsiloxane (PDMS)-containing polyimide copolymer membranes

ty10086 提交于 周四, 08/26/2021 - 12:40
研究了紫外光照射对无规分段聚酰亚胺-硅氧烷( PIS )共聚物薄膜气体渗透性能的影响。以4,4\"- (六氟异丙基亚甲基)二苯甲酸酐( 6FDA )和3,3\",4,4\"-苯甲酮四羧酸二酐( BTDA )为原料,以2,4 -二氨基二甲苯( DAM )和不同量的二胺封端聚二甲基硅氧烷( PDMS )低聚物( Mn   =  3000   g / mol ),以7∶3   M的比例进行酯酸亚胺化反应,合成了随机分段共聚物。这些共聚物的溶剂铸膜在365 nm的空气中被紫外光照射,引起交联和光氧化。在温度为35  ℃,上游压力为2 ~ 18   atm  的条件下,测定了H2、O2、N2、CH4和CO2的纯气体透过率.结果表明,PIS系列共聚物的气体透过率降低,紫外交联和光氧化使自由体积减小,所有气体对的选择性提高.

具有宽工作温度范围的可编程和热淬复合纱线驱动器

ty10086 提交于 周三, 08/25/2021 - 16:57
摘要\n执行器在智能机器人、可变形纺织品和可穿戴设备等领域有着广泛的应用,其中基于纤维的卷曲线型执行器因其良好的灵活性、高应力和应变而特别有优势。然而,其性能受到所用材料的限制,其微观结构不易设计和控制。本文提出了一种用于作动器的工程复合纱线的新方法。它通过在材料特性和器件结构方面提供广泛的设计选择,为克服这些困难提供了新的解决方案。这里举例说明了一种具有广泛工作温度的可编程热硬螺旋复合纱线驱动器( HCYAs )的工程设计。选用聚酰亚胺( PI )和聚二甲基硅氧烷( PDMS )制备HCYAs,在~ 50℃~ 160℃的1.2 MPa下拉伸驱动20.7 %,比功竞争( 158.9 J kg–1,4倍天然肌肉)。在拉伸变形不变的情况下,PI / PDMS HCYA将20 ~ 100℃的应力提高了近一倍,而且,PI / PDMS HCYA的拉伸刚度随温度的升高而增大,这令人惊讶。通过电热驱动PI / Cu / PDMS HCYAs,机器人手和压力可调的压缩绷带被展示在机器人和可穿戴设备中的潜在应用。

有机改性硅气凝胶与聚合物复合材料的分子间相互作用:分子模拟研究

ty10086 提交于 周三, 08/25/2021 - 16:26
通过全原子分子动力学模拟研究了两种ORMOSIL基复合体系:( 1 )聚二甲基硅氧烷( PDMS )与正硅酸乙酯( TMOS )和乙烯基三甲氧基硅烷( VMTS );( 2 )聚酰亚胺/聚酰胺酸为3,3 ',4,4 ' -联苯四甲酸二酐- 4,4 ' -氧二苯胺( BPDA-ODA )和均苯四甲酸二酐- 3,5 -二氨基苯甲酸( PMDA-DBA )的正硅酸乙酯( TEOS )和3 -氨丙基三乙氧基硅烷( APTES )或TEOS / ( 3 -环氧丙基)三甲氧基硅烷( GLYMO )。对于体系( i ),得出PDMS %   mol的增加导致二氧化硅初级粒子形成较小的团聚体,这是因为有利于二氧化硅- PDMS氢键的二氧化硅-二氧化硅氢键数量减少,静电作用和范德华作用对两相之间的整体吸引力贡献显著。在体系( ii )中,聚酰亚胺/聚酰胺酸中,二氧化硅的羟基和胺基与酸酐、羰基、羧基和末端胺基形成氢键,而在TEOS / GLYMO中,最常见的氢键是二氧化硅的羟基与聚合物链上的羧基或末端胺基之间形成的氢键,在后一种复合体系中,范德华力在二氧化硅粒子与聚合物之间的粘结性能中起着更重要的作用。