PA6/POSS纳米杂化材料的结构与性能

采用熔融共混方法,用环氯官能化笼型倍半硅氧烷(POSS)改性聚酰胺(PA)6,制备了PA 6/POSS纳米杂化材料.研究表明:环氧化POSS可在一定程度上改善PA 6的低温抗冲击性能,在w(POSS)低于3％时,可提高杂化材料的拉伸强度.此外,环氧化POSS可显著改善杂化材料的介电性能,将环氧化POSS加入PA 6基体...     

G-POSS/CE杂化材料的制备及性能研究

采用共混法制备八环氧基POSS(G-POSS)/氰酸酯树脂(CE)有机-无机杂化材料。研究了环氧基POSS含量对杂化材料的固化反应、介电性能、力学性能等的影响,并对杂化材料的微观相态结构进行了表征和分析。结果表明,G-POSS的引入使氰酸酯树脂基体的介电性能显著改善,同时反应活性、韧性等都有所提高。且当G-POSS的质量分数为2.5%时,杂化材料的介电性能、力学强度和刚性提高较为明显,且其断面形貌呈韧性断裂。     

EP/POSS/SiO2纳米复合材料性能研究

以自制的两种不同黏度的环氧基倍半硅氧烷(POSS)为改性剂,对双酚A型环氧树脂(EP)/4,4’–二氨基二苯砜(DDS)进行改性,制备EP/POSS杂化材料。再以纳米SiO2为填料制备了EP/POSS/SiO2纳米复合材料。结果表明,与EP相比,杂化材料和纳米复合材料的弯曲强度和弯曲弹性模量都有所提高,其中纳米复合材料(分别添加低黏度和高黏度的POSS)的弯曲弹性模量分别提高了15.03%和9.44%,添加高黏度的POSS和纳米SiO2后其杂化材料和纳米复合材料体系的弯曲强度均有所提高,杂化材料和纳米复合材料的最大分解温度和在高温时的热残留量都有所提高。     

聚丁二烯/烯丙基异丁基多面体低聚倍半硅氧烷纳米杂化材料的形貌及性能

对采用活性负离子聚合法制得的聚丁二烯( PB)/烯丙基异丁基多面体低聚倍半硅氧烷(A - POSS)纳米杂化材料进行硫化,采用X射线衍射仪、扫描电子显微镜、差示扫描量热法、热重分析、动态力学性能分析等手段,研究了A - POSS含量对硫化PB/A -POSS纳米杂化材料的微观形貌、耐热性能和动态力学性能的影响.结果表明...     

环氧树脂/POSS杂化材料力学性能和耐热性研究

以自行合成的环氧基倍半硅氧烷（POSS）为改性剂,分别对环氧树脂139S/六氢苯酐和环氧树脂BE 188EL/六氢苯酐进行改性,制备环氧树脂/POSS杂化材料。力学性能分析结果表明,两种杂化材料的冲击强度和弯曲强度都有明显的提高,冲击强度分别提高了57.45 %和32.26 %,弯曲强度分别提高了9.23 %和5.07 %。热性能分析结果表明,两种杂化材料在高温时的热残留量都有所提高,分别提高了50.19 %和20.16 %。两种杂化材料的热膨胀系数也得到了降低,即热稳定性得到了提高。     

八环氧基笼型倍半硅氧烷/EP杂化材料的制备及性能研究

以三乙烯四胺(TETA)为固化剂,采用共混法制备八环氧基笼型倍半硅氧烷(G-POSS)/环氧树脂(EP)杂化材料。研究了环氧基POSS含量对杂化材料的固化反应、介电性能、力学性能及热性能等影响,并对杂化材料的微观相态结构进行了表征和分析。结果表明,G-POSS的引入提高了EP的反应活性,制备的杂化材料透明性良好,力学性能、介电性等都有所提高;且当m(G-POSS)m∶(EP)=20 1∶00时,杂化材料的介电性能、力学强度和刚性提高较为明显,且其断面形貌呈韧性断裂。其拉伸强度为67.8 MPa、断裂伸长率为3.44%、弯曲强度为116.7 MPa,与纯EP相比,分别提高了83.20%、320.13%、49.17%。     

EPDM/POSS纳米杂化材料防火性能及力学性能的研究

以三元乙丙橡胶(EPDM)为原料,笼形八乙烯基硅倍半氧烷(OVP)及膨胀阻燃体系(IFR)为添加剂,制备了EPDM/POSS纳米杂化材料,并使用热重分析仪、锥形量热仪及烟密度箱等测试了其热性能、烟火性能及力学性能。结果表明,与纯EPDM胶料相比,添加了OVP的EPDM/POSS杂化材料的热稳定性、阻燃性能及力学性能均有所提升,当OVP加入3份时,起始热分解温度提高27.5℃,峰值热释放速率降低9.2%,拉伸强度提高26.5%,烟密度显著降低,说明OVP可提升EPDM/POSS杂化材料的综合性能。     

氨基POSS/环氧树脂有机无机杂化材料的动态力学性能

为了提高环氧树脂(EP)的综合性能,以含氨基官能团的笼型倍半硅氧烷(POSS)作为EP的改性剂,得到有机-无机POSS改性EP杂化树脂;然后以4,4′-二氨基二苯基砜(DDS)为固化剂对杂化树脂进行固化,得到有机-无机杂化材料。重点考察了POSS含量对杂化材料动态力学性能的影响。结果表明:不同杂化材料体系均呈单相结构,POSS在EP基体中分散较均匀,说明两者间相容性良好;随着POSS含量的不断增加,杂化材料体系的玻璃化转变温度(Tg)增大,与传统杂化材料不同的是损耗峰强度随POSS含量增加而降低,但损耗峰宽度几乎不变。     

POSS/聚合物复合材料的制备以及在尼龙中应用的研究进展

多面体低聚倍半硅氧烷(polyhedral oligomeric silsesquioxane,POSS)是一种具有独特中空刚性结构的纳米级材料,作为无机-有机的新型杂化材料,其可设计的分子杂化结构使得POSS能够在聚合物基体中达到分子水平或纳米级别的良好分散,有效提升材料的表面性能、热性能、介电性能和力学性能等,极大地拓宽了在聚合物中的应用领域。本文主要针对POSS的合成制备方法、功能化改性方法、POSS形貌与性能的关系、POSS/尼龙复合材料的制备方法等进行综述。主要介绍POSS的合成方法、官能化方法及POSS/尼龙复合材料的制备方法及结构与性能的关系。未来随着POSS官能化方法的改进必然能够将POSS引入更多的聚合物基体内并实现更好的分散,POSS在聚合物中的应用范围将不断扩大。     

笼型倍半硅氧烷改性氰酸酯树脂杂化材料研究

采用甲基笼型倍半硅氧烷(POSS)改性双酚A二氰酸酯(BADCy),研究了不同含量的POSS对BADCy结构及性能的影响,利用傅立叶变换红外光谱仪考察了BADCy/POSS杂化材料的反应性,研究了BADCy/POSS杂化材料的介电性能、热稳定性和耐湿热性能.结果表明,BADCy/POSS杂化材料具有比BADCy低的介电常数,有望用作高性能印刷线路板基体材料.     

交联POSS-聚氨酯胶的结构与性能研究

采用含八乙烯基的POSS为原料,与不同的聚氨酯预聚体进行共聚,合成了一系列POSS基高分子胶粘剂材料。通过表面红外(ATR)、广角X射线衍射(WAXD)和动态力学分析(DMTA)等方法表征了杂化胶粘剂的热性能。     

Synthesis of eugenol‐based polybenzoxazine–POSS nanocomposites for low dielectric applications

Nanocomposites of eugenol‐based polybenzoxazines/amine containing polyhedral oligomeric silsesquioxane (POSS) have been prepared through copolymerization of allyl‐containing benzoxazine compounds and amine containing POSS. Their structures, curing behaviour, and thermomechanical properties were characterized by Fourier transform infrared, ¹H‐NMR, ¹³C‐NMR, X‐ray diffraction, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermogravimetric analysis (TGA). The nanoscale dispersion of POSS cores in the nanocomposites was verified by scanning electron microscopy, atomic force microscopy, and transmission electron microscopy studies. The results from DMA and TGA show that the thermal stability, crosslink density and flame retardance of the nanocomposites increased when small amounts of POSS cores (5 wt%) were incorporated into the system. Further the POSS incorporation reduces the dielectric constant of the benzoxazines to about 1.32. Hence, the prepared nanocomposites could be used as ultra‐low‐k materials for advanced microelectronics. POLYM. COMPOS., 36:1973–1982, 2015. © 2014 Society of Plastics Engineer     

Polyimide and polyhedral oligomeric silsesquioxane nanocomposites for low-dielectric applications

A novel polyimide (PI) hybrid nanocomposite containing polyhedral oligomeric silsesquioxane (POSS) with well defined architecture has been prepared by copolymerization of octakis(glycidyldimethylsiloxy)octasilsesquioxane (Epoxy-POSS), 4,4′-oxydianiline diamine (ODA), and 4,4′-carbonyldiphthalic anhydride (BTDA). In these nanocomposite materials, the equivalent ratio of the Epoxy-POSS and ODA are adjustable, and the resultant PI-POSS nanocomposites give variable thermal and mechanical properties. More importantly, we intend to explore the possibility of incorporating POSS moiety through the Epoxy-POSS into the polyimide network to achieve the polyimide hybrid with lower dielectric constant (low-k) and thermal expansion. The lowest dielectric constant achieved of the POSS/PI material (PI-10P) is 2.65 by incorporating 10 wt% Epoxy-POSS (pure PI, k=3.22). In addition, when contents of the POSS in the hybrids are 0, 3, 10 wt% (PI-0P, PI-3P, PI-10P), and the resultant thermal expansion coefficients (TEC) are 66.23, 63.28, and 58.25 ppm/°C, respectively. The reduction in the dielectric constants and the resultant thermal expansion coefficients of the PI-POSS hybrids can be explained in terms of creating silsesquioxane cores of the POSS and the free volume increase by the presence of the POSS-tethers network resulting in a loose PI structure.     

POSS/PS复合材料的制备及其热性能研究

以1,3,5,7,9,11,13-苯基-15-氯丙基笼型倍半硅氧烷(POSS-Cl)与二乙醇胺进行反应,将末端氯基团转化为两个端羟基,通过羟基与2-溴代异丁酰溴的酯化反应得到POSS-(Br)2引发剂,并运用原子转移自由基聚合(ATRP)成功合成了一种新型POSS/PS复合材料。采用傅里叶红外(FTIR)、核磁共振(NMR)等手段对POSS和POSS/PS的结构进行了表征。通过差示扫描量热(DSC)和热失重(TGA)分析对POSS/PS复合材料的热性能进行了研究。结果表明:POSS单元的引入能显著提高聚合物的热稳定性。     

Mechanical,thermal, and viscoelastic response of novel in situ CTBN/POSS/epoxy hybrid composite system

The present study focuses on the preparation of a novel hybrid epoxy nanocomposite with glycidyl polyhedral oligomeric silsesquioxane (POSS) as nanofiller, carboxyl terminated poly(acrylonitrile‐co‐butadiene) (CTBN) as modifying agent and diglycidyl ether of bisphenol A (DGEBA) as matrix polymer. The reaction between DGEBA, CTBN, and glycidyl POSS was carefully monitored and interpreted by using Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC). An exclusive mechanism of the reaction between the modifier, nanofiller, and the matrix is proposed herein, which attempts to explains the chemistry behind the formation of an intricate network between POSS, CTBN, and DGEBA. The mechanical properties, such as tensile strength, and fracture toughness, were also carefully examined. The fracture toughness increases for epoxy/CTBN, epoxy/POSS, and epoxy/CTBN/POSS hybrid systems with respect to neat epoxy, but for hybrid composites toughening capability of soft rubber particles is lost by the presence of POSS. Field emission scanning electron micrographs (FESEM) of fractured surfaces were examined to understand the toughening mechanism. The viscoelastic properties of epoxy/CTBN, epoxy/POSS, and epoxy/CTBN/POSS hybrid systems were analyzed using dynamic mechanical thermal analysis (DMTA). The storage modulus shows a complex behavior for the epoxy/POSS composites due to the existence of lower and higher crosslink density sites. However, the storage modulus of the epoxy phase decreases with the addition of soft CTBN phase. The T_g corresponding to epoxy‐rich phase was evident from the dynamic mechanical spectrum. For hybrid systems, the T_g is intermediate between the epoxy/rubber and epoxy/POSS systems. Finally, TGA (thermo gravimetric analysis) studies were employed to evaluate the thermal stability of prepared blends and composites. POLYM. COMPOS., 37:2109–2120, 2016. © 2015 Society of Plastics Engineers     

Hybrid nanocomposites based on novolac resin and octa(phenethyl) polyhedral oligomeric silsesquioxanes (POSS): miscibility, specific interactions and thermomechanical properties

Hybrid nanocomposites were prepared via solution blending of octaphenethyl POSS into novolac resin. The resulted hybrid blends were investigated by Fourier-transformed infrared spectra (FTIR), polarized optical microscopy (POM), wide X-ray diffraction and differential scanning calorimetry (DSC). FTIR results showed that there existed intermolecular hydrogen bond between the hydroxyl groups of the phenolic resin and POSS siloxane groups, which could promote POSS to disperse well in the polymer matrix up to 20 wt% POSS loading. At higher POSS loading, POSS would aggregate and lead to macrophase separation, which was demonstrated by POM, DSC and WXRD. Finally, hexamethylene tetramine was used to cure the novolac blends to form hybrid network phenolic nanocomposites. Dynamic mechanical analysis results showed that the storage modulus of the hybrid networks was improved up to 20 wt% POSS loading; the T _g was increased with increasing POSS content and higher than that of the control phenolic resin except that 5 wt% POSS loading. Thermo gravimetric analysis showed that the thermal stability of hybrid networks was also enhanced with the incorporation of POSS.     

The effects of structure of POSS on the properties of POSS/PMMA hybrid materials

Octa‐vinyl polyhedral oligomeric silsesquioxane (V‐POSS) and octa‐(methacryloxy) propyl polyhedral oligomeric silsesquioxane (M‐POSS) were incorporated into PMMA to prepare POSS/PMMA hybrid materials at molecular level via in situ polymerization. The resulting hybrid materials showed only swelling instead of solution in ethyl acetate, while pristine PMMA completely dissolved in ethyl acetate; moreover, the M‐POSS/PMMA hybrid materials exhibited more excellent resistance to solvent stress cracking. An excellent transparency was observed for all hybrid materials. Incorporation of V‐POSS and M‐POSS significantly improved thermal properties of PMMA. The thermal decomposition temperature of hybrid materials was enhanced except a slightly compromised initial decomposition temperature. The hybrid materials prepared with 0.2–0.6 mol% M‐POSS or V‐POSS improved the reinforcing and toughening properties in comparison to pristine PMMA. Also, the incorporation of POSS decreased the dielectric constant and dielectric loss of the hybrid materials with more voids introduced into the composites no matter the structure of POSS. POLYM. ENG. SCI., 55:565–572, 2015. © 2014 Society of Plastics Engineers     

POSS/PMMA杂化材料的制备及性能研究

采用八乙烯基倍半硅氧烷（OV-POSS）通过原位聚合法制备了POSS/PMMA杂化材料。通过FTIR、SEM,EDS以及力学性能和透光性雾度的测定等方法对杂化材料的结构和性能进行了表征。结果表明,POSS的加入对PMMA可见光的透过性无影响。POSS含量较低时,POSS的引入能明显改善材料力学性能,但当POSS含量较高时,力学性能下降。当POSS的含量为0.6%时,与纯的PMMA相比,断裂伸长率略有降低,降低了5.8%,然而,其他力学性能均有提高,其中,拉伸模量和强度分别提高了22.7%和32.0%,弯曲强度和模量分别提高了9.8%和27.0%。     

Novel phenyl‐POSS/polyurethane aqueous dispersions and their hybrid coatings

A facile and rapid preparation of 3‐(2‐aminoethylamino)propylheptaphenylPOSS (AA‐POSS), a special phenyl‐POSS that contains two functional amino groups (Scheme 1), is demonstrated by the corner‐capping method. Then AA‐POSS forms a series of novel phenyl‐POSS/PU aqueous dispersions. The structure of AA‐POSS has been confirmed by ¹H, ¹³C, ²⁹Si NMR, and ESI‐MS. The POSS/PU hybrid films are studied by Fourier transform infrared spectrometer (FT‐IR), gel permeation chromatography (GPC), scanning electron microscope (SEM), X‐ray diffraction (XRD) spectra, differential scanning calorimetry (DSC) analysis, and thermal gravimetric analyzer (TGA). FT‐IR and GPC are conducted to validate the chemical structure of the hybrid PU. The properties of hybrid films display significant changes with notable increases in T_g, thermal properties, tensile strength, as well as surface hydrophobicity. These changes are attributed to the incorporation of novel POSS into PU. Moreover, these significant material property enhancements are achieved at low levels of POSS incorporation (only 4%). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1611–1620, 2013