Heat-resistant and high-conductivity nanometer zinc oxide-graphene TPU and preparation method thereof
阅读说明：本技术 一种耐热且高传导的纳米氧化锌-石墨烯tpu及其制备方法 (Heat-resistant and high-conductivity nanometer zinc oxide-graphene TPU and preparation method thereof ) 是由 叶显柱 齐燕 余致远 于 2020-06-01 设计创作，主要内容包括：本发明公开了一种耐热且高传导的纳米氧化锌-石墨烯TPU及其制备方法,属于石墨烯与纳米颗粒负载组装、原位聚合技术领域。首先将GO纳米片利用SDBS在超声去离子水中与纳米氧化锌粒子组装成负载态的氧化石墨烯纳米片；在不破坏原溶胶结构的前提下进行溶解-还原-冷冻-萃取过程；然后加入缔合催化剂的聚醚二醇溶胶与二异氰酸酯低聚物反应生成最终功能性PGZ弹性体。本发明利用纳米组装-还原-冷冻萃取技术,制备了具有超高界面功能的支撑增强屏蔽石墨烯/纳米氧化锌/热塑性聚氨酯(TPU)。由于纳米效应和纳米片的正堆积行为,初始分解温度被有效地延迟；并在聚合过程中掺杂的GZ界面使得玻璃化转变温度明显向高温区移动,使得TPU链段稳定性获得较大的提升。(The invention discloses a heat-resistant and high-conductivity nano zinc oxide-graphene TPU and a preparation method thereof, and belongs to the technical field of graphene and nanoparticle load assembly and in-situ polymerization. Firstly, assembling GO nano-sheets and nano-zinc oxide particles in ultrasonic deionized water by using SDBS to form loaded graphene oxide nano-sheets; the dissolving-reducing-freezing-extracting process is carried out on the premise of not damaging the original sol structure; the polyether diol sol with the associated catalyst is then reacted with the diisocyanate oligomer to produce the final functional PGZ elastomer. The invention utilizes the nano assembly-reduction-freezing extraction technology to prepare the support reinforced shielding graphene/nano zinc oxide/Thermoplastic Polyurethane (TPU) with the ultrahigh interface function. Due to the nano-effect and the positive stacking behavior of the nanoplates, the initial decomposition temperature is effectively delayed; and the doped GZ interface in the polymerization process enables the glass transition temperature to obviously move to a high-temperature area, so that the stability of the TPU chain segment is greatly improved.)
1. A preparation method of heat-resistant and high-conductivity nanometer zinc oxide-graphene TPU is characterized by comprising the following steps:
step 1, firstly, assembling GO nano-sheets and nano-zinc oxide particles in ultrasonic deionized water by using SDBS to form loaded graphene oxide nano-sheets;
step 2, performing dissolving-reducing-freezing-extracting processes on the premise of not damaging the original sol structure;
and 3, adding polyether glycol sol associated with a catalyst to react with diisocyanate oligomer to generate the final functional PGZ elastomer.
2. The method for preparing the heat-resistant and highly conductive nano zinc oxide-graphene TPU of claim 1, wherein the step 1 is: dispersing and ultrasonically dissolving nano ZnO particles and graphene oxide in deionized water according to a preset ratio, stirring at the speed of 10-20000r/min, and adding a sodium dodecyl benzene sulfonate solution for load activation.
3. The method for preparing the heat-resistant and highly conductive nano zinc oxide-graphene TPU according to claim 2, wherein the amount of the sodium dodecylbenzenesulfonate added is 0.1 to 5% by weight of the mixed solution of ZnO particles and graphene oxide.
4. The method for preparing the heat-resistant and highly conductive nano zinc oxide-graphene TPU according to claim 1, wherein the dissolving process in the step 2 is specifically as follows: the loaded graphene oxide nanosheet is dissolved in polyether glycol, wherein the stirring temperature is 70-105 ℃, the stirring speed is 10-10000 r/min, and the stirring time is 0-100h until the deionized water is converted into a viscous oil state.
5. The method for preparing the heat-resistant and highly conductive nano zinc oxide-graphene TPU according to claim 1, wherein the reduction process in the step 2 is specifically: during the dissolving and stirring process, N is added2H4·H2O and NH3·H2Mixed solution of O, wherein, N2H4·H2O and NH3·H2The molar ratio of O is 1: (4-7).
6. The method for preparing the heat-resistant and highly conductive nano zinc oxide-graphene TPU according to claim 1, wherein the freezing process in the step 2 is specifically: and (3) freeze-drying the homogeneous phase colloid mixture at-25 ℃ for 0.1-100 hours to obtain the TDI-GZ sol with the staggered nano-flakes.
7. The method for preparing the heat-resistant and highly conductive nano zinc oxide-graphene TPU according to claim 1, wherein the step 3 is specifically: and (3) reacting the modified sol and diisocyanate oligomer by adopting a spray reactor at 50-70 ℃, wherein the isocyanate index controlled by the mass ratio is fixed at R = 0.7-1.25.
8. The heat-resistant and high-conductivity nano zinc oxide-graphene TPU material is prepared by the preparation method of the heat-resistant and high-conductivity nano zinc oxide-graphene TPU material as claimed in any one of claims 1-7.
Technical Field
The invention belongs to the technical field of graphene and nanoparticle load assembly and in-situ polymerization, and particularly relates to a heat-resistant and high-conductivity nano zinc oxide-graphene TPU and a preparation method thereof.
Background
Thermoplastic Polyurethane (TPU) has been widely used in the industries of decoration, cable, sealing, etc. due to its characteristics of viscoelasticity, plasticity, impregnation resistance, antibacterial activity, etc. However, with the increasing demand of people for various functions, the method has great prospect for photoelectric application and thermal resistance, and the deep exploration of interface modification has important significance for providing TPU meeting mechanical strengthening, thermal stability or ultraviolet resistance. At present, the research on the assembly of graphene nanomaterials into three-dimensional (3D) forms such as aerogels, microporous or mesoporous frameworks, and hydrogels has progressed significantly. Graphene or graphene oxide, an excellent monoatomic laminar flow material, has pi bonds throughout the atomic layer, and has been demonstrated to be an excellent modifier to provide a variety of functional characteristics to the elastomeric structure. In particular, the graphene loaded with the active nanoparticles can show different performances in terms of phonon/electron/magnetism/stress and the like, such as applications in electromagnetic shielding, energy storage, catalysis, photoelectricity and the like. Previous studies have conducted modifications, such as nanodispersion or crosslinking, to the dissolved or melted TPU matrix. However, studies on functional multi-group interfaces in the in situ reaction process have been rarely reported, and one very important reason is that the nano-size or laminar structure is difficult to distribute in the high viscosity monomer, and the activity effect is not well maintained. In fact, the in-situ polymerization reaction of polyurethane with the catalytic process is relatively fast (30-50 s), forming an obstacle to the construction of one-or two-dimensional uniform nano-networks in the matrix. In the work, the thermal conductivity and the structural stability are improved by efficiently loading the transition nanocrystalline metal oxide on the graphene nanosheet and introducing the transition nanocrystalline metal oxide into the in-situ synthesis process of the TPU. Finally, a preparation route of nano assembly, freezing, extraction and polymerization is provided, a three-dimensional GZ (rGO-ZnO) network is formed and has high functionality, and a nano effect and a heat conduction path can be fully constructed in such a way.
Disclosure of Invention
The purpose of the invention is as follows: provides a preparation method of heat-resistant and high-conductivity nano zinc oxide-graphene TPU, so as to solve the problems involved in the background technology.
The technical scheme is as follows: a preparation method of heat-resistant and high-conductivity nano zinc oxide-graphene TPU comprises the following steps:
and 3, then adding the polyether glycol sol associated with the catalyst to react with diisocyanate oligomer (PMDI) to generate the final functional PGZ elastomer.
Preferably, the
Preferably, the addition amount of the sodium dodecyl benzene sulfonate is 0.1-5% of the weight of the mixed solution of the ZnO particles and the graphene oxide.
Preferably, the dissolving process in the
Preferably, the reduction process in the
Preferably, the freezing process in
Preferably, the
The invention also provides a heat-resistant and high-conductivity nano zinc oxide-graphene TPU material prepared based on the preparation method.
Has the advantages that: the invention relates to a preparation method of heat-resistant and high-conductivity nano zinc oxide-graphene TPU (thermoplastic polyurethane), which utilizes a nano assembly-reduction-freezing extraction technology to prepare support reinforced shielding graphene/nano zinc oxide/Thermoplastic Polyurethane (TPU) with an ultrahigh interface function. Due to the nano-effect and the positive stacking behavior of the nanoplates, the initial decomposition temperature (Td, increased by 47 ℃ and 38 ℃) is effectively delayed. The GZ interface doped in the polymerization process enables the glass transition temperature (Tg) to obviously move to a high-temperature region, so that the stability of the TPU chain segment is greatly improved.
Drawings
Fig. 1 is a schematic assembly of the TPU of the present invention.
Fig. 2 is a diagram showing the actual appearance and effect of the TPU of the present invention.
FIGS. 3a-3d are SEM micrographs of GZ dispersed in deionized water and TDI2000 monomer in accordance with the present invention.
FIG. 3e is a TEM image of r-GZ in the present invention.
Fig. 3f is an HRTEM electron micrograph of the graphene oxide nanoplatelets in the loaded state in accordance with the present invention.
FIG. 3g is an SEM micrograph of a TPU according to the invention.
FIG. 3h is an SEM micrograph of PGZ of the present invention.
FIGS. 4a, 4b are TGA analysis plots of the TPU and PGZ of the present invention.
FIG. 5 is a DSC analysis chart of TPU and PGZ of the present invention.
Detailed Description
In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the invention.
As shown in fig. 1, a preparation method of a heat-resistant and highly conductive nano zinc oxide-graphene TPU includes the following steps:
And 2, performing the dissolving-reducing-freezing-extracting process on the premise of not damaging the original sol structure. Preferably, the dissolving process is specifically: the loaded graphene oxide nanosheet is dissolved in polyether glycol, wherein the stirring temperature is 70-105 ℃, the stirring speed is 10-10000 r/min, and the stirring time is 0-100h until the deionized water is converted into a viscous oil state. The reduction process specifically comprises the following steps: during the dissolving and stirring process, N is added2H4·H2O and NH3·H2Mixed solution of O, wherein, N2H4·H2O and NH3·H2The molar ratio of O is 1: (4-7). The freezing process specifically comprises the following steps: and (3) freeze-drying the homogeneous phase colloid mixture at-25 ℃ for 0.1-100 hours to obtain the TDI-GZ sol with the staggered nano-flakes.
And 3, then adding the polyether glycol sol associated with the catalyst to react with diisocyanate oligomer (PMDI) to generate the final functional PGZ elastomer. Preferably, the modified sol and diisocyanate oligomer are reacted by adopting a spray reactor at 50-70 ℃, and the isocyanate index controlled by the mass ratio is fixed at R = 0.7-1.25.
Turning to fig. 2, there are shown a schematic appearance diagram of the individual states during the manufacturing process, an appearance diagram and an elasticity effect diagram of the PGZ product.
Turning to fig. 3a to 3h, a series of assembled morphological structures of GZ nanoplates can be further observed. Indeed, the frozen extracted GZ nanoplates can still remain relatively uniformly dispersed in deionized water and TDI2000 monomers as shown in SEM fig. 3a-3d and TEM fig. 3 e. The layered structure of the nano ZnO-loaded particles (marked by dashed boxes) is clearly visible. As shown in the HRTEM image (dashed oval box labeled) of fig. 3f, the encapsulation effect of graphene nanoplatelets can also be observed at high resolution stage, as predicted in the initial assembly design. The multi-electron lattice of the GZ nanosheets, with interplanar spacings of 0.52nm and 0.34nm, corresponds to the and (0002) lattice planes (marked by dashed rectangular boxes) of nano-zinc oxide and graphene.
Turning to fig. 4 to 5, TGA analysis shows that the glass transition temperature is effectively raised (as shown in fig. 4a, 4 b). The glass transition temperature (Tg) as the initial temperature for exciting polymer bonding has been used as a structural parameter to show the strengthening mechanism of the polymer matrix. In the DSC curve (FIG. 5) of the PGZ composite material, there are three main characteristic peaks, namely, the glass transition of the soft polyether segment (-33.2-22.5 ℃), the glass transition of the hard benzene segment (3.9-5.4 ℃) and the melting peak of the benzene segment (45.1-54.3 ℃). With the introduction of the GZ interface, it is noteworthy that: the glass transition peak is significantly attenuated and moves toward the high temperature region. This may be due to the surface activity of the nanoplatelets and the strong interaction between the active nanoparticles and the segment. In most cases, an increase in Tg is predictive of mechanical reinforcement of the molecular chain. The overall enhanced performance thereof should result from the level of uniform dispersion of the assembled GZ network into isolated continuous nanoplates to achieve payload transfer from the TPU molecular chain. This also results in a more uniform stress distribution and minimizes the presence of stress concentration centers.
The prepared graphene-nano zno (GZ) interface network is analyzed and verified by means of SEM, TEM, TG/DMA and the like. Due to the nano-effect and the positive stacking behavior of the nanoplates, the initial decomposition temperature (Td, increased by 47 ℃ and 38 ℃) is effectively delayed. The results show that the doped GZ interface during polymerization shifts the glass transition temperature (Tg) significantly towards the high temperature region.
The invention will now be further described with reference to the following examples, which are intended to be illustrative of the invention and are not to be construed as limiting the invention.