PC/PETG共混物熔体的流变性能

采用熔融共混工艺制备了聚碳酸酯（PC）/聚对苯二甲酸乙二醇酯-1,4-环己烷二甲醇酯（PETG）共混物,测试了PC/PETG共混物的熔融指数,研究了共混物的复数黏度与剪切频率、温度以及物料组成的关系。结果表明,PETG的引入改善了PC的成型加工流变性能;PC/PETG共混物呈现出假塑性流体特性,表现出切力变稀的现象;共混物随着温度的升高,复数黏度下降,随着PETG含量的增加,共混物黏度呈现下降的趋势。     

PETG/PC共混物的制备及结构性能研究

采用双螺杆挤出机将聚对苯二甲酸乙二醇酯-1,4-环己烷二甲醇酯( PETG)与聚碳酸酯(PC)熔融共混,制备PETG/PC共混物,研究了共混物的透明性、力学性能、微观形态结构以及流变性等性能.研究发现,制备的PETG/PC共混物透光率约为91%;PETG、PC相容性很好;PETG/PC共混物为韧性断裂;随着PC含量的增...     

PETG-酪蛋白胶3D打印形状记忆塑料的制备研究

以聚对苯二甲酸乙二醇-1,4-环己烷二甲醇酯(PETG)为基体材料,加入一定量的酪蛋白胶使其具有一定的形状记忆特性。实验采用熔融共混法制备形状记忆复合塑料,平板硫化仪热模压复合塑料成片材,3D打印机对片材建模打印测试用样条。对3D打印样品影响因素进行了探讨,研究发现3D打印样品的应力-应变在一定程度内满足线性关系,而打印速度控制在40～80 mm/s之间能保证3D打印样品的质量,打印厚度控制在0.1～0.3 mm之间能保证打印样品良好的冲击强度和弯曲强度。研究表明:复合塑料的流动性能随酪蛋白胶含量的增大而增强,实验温度在120℃以内时,酪蛋白胶含量的增大有助于复合塑料热形变回复能力的提升。且温度越高,酪蛋白胶含量越大,形状记忆的回复时间越短。     

PETG/PC/TPU合金共混改性研究

采用双螺杆挤出机对聚氨酯(TPU)、聚碳酸酯(PC)和聚对苯二甲酸乙二醇酯-1,4-环己烷二甲醇酯(PETG)进行熔融共混,制备出PETG/PC/TPU三元共混物,研究了不同共混物的力学性能、耐溶剂性能、软化温度及微观形态结构等性能。研究发现,对于同样硬度的TPU,聚酯型TPU对改善合金的拉伸强度和冲击强度均优于聚醚型TPU与PETG/PC的共混。硬度较低的聚酯型TPU可较大幅度提高PETG/PC/TPU合金的韧性。TPU的加入可明显改善PETG/PC/TPU合金的耐溶剂性。     

抗氧剂1010对3D打印用聚乳酸氧化降解性能的影响

为研究抗氧剂1010（KY1010）对3D打印用聚乳酸（PLA）氧化降解性能的影响,以PLA和KY1010为原料,通过挤出成型工艺制得3D打印用PLA丝材,并采用FDM工艺制备复合材料,研究KY1010添加量对PLA丝材拉伸性能、动态热机械性能、氧化诱导期以及复合材料力学性能的影响。结果表明,KY1010可有效改善PLA的抗氧化性,随KY1010添加量的增加,PLA丝材拉伸强度和储能模量先增加后减少,氧化诱导时间和氧化诱导温度逐渐增加;复合材料拉伸强度和弹性模量先增加后减少,冲击强度和缺口冲击强度逐渐提高;当KY1010添加量为0.5 %（质量分数,下同）时,PLA丝材的综合性能最好,PLA丝材的氧化诱导时间和氧化诱导温度分别提高了1 655.19 %和16.91 %,拉伸强度提高了15.35 %,储能模量最佳;复合材料的拉伸强度和弹性模量分别提高了26.04 %和33.23 %。     

PPC-MA/PETG共混型生物降解材料的结构与性能研究

采用熔融共混法制备了马来酸酐(MA)封端聚碳酸亚丙酯(PPC)和聚对苯二甲酸乙二醇酯-1,4-环己烷二甲醇酯(PETG)的共混物(PPC-MA/PETG),采用套管上吹法将共混物吹塑成膜.通过差示扫描量热仪(DSC)、热失重分析(TGA)及扫描电子显微镜(SEM)等手段系统地研究了共混物的热、力学性能及形貌.结果表明:PPC-MA/PETG共混物为部分相容体系;MA封端PPC可以提高PPC的热分解温度(T-5%),PETG与PPC-MA共混进一步提高了PPC的热性能;当PETG含量低时,PETG作为岛相分散在PPC基体中,随着含量的增加,共混物将发生"海-岛"结构转变成"海-海"结构;共混物薄膜的力学性能较纯PPC大幅增强,从4.7MPa提高到16.93MPa.PPC-MA与PETG共混可以获得力学性能较好的膜材料,改善PPC材料的缺陷,在包装、生物医用材料等领域具有广阔的应用前景.     

PBS/PLA/滑石粉3D打印线材制备及熔融沉积成型工艺研究

以聚丁二酸丁二醇酯(PBS)为基体,滑石粉和聚乳酸(PLA)为改性剂,采用熔融挤出法制备了PBS/PLA/滑石粉三维 （3D）打印线材,并对其进行了熔融成型研究。通过分析结晶性能、流变性能、力学性能、断面形貌和打印效果对PBS/PLA/滑石粉体系进行了探究。结果表明,PLA的加入使PBS的结晶温度下降了5 ℃;随着PLA含量的增加,材料的复数黏度、储能模量和损耗模量均得到提高;而拉伸强度则随PLA含量的增加下降了1.71 MPa,缺口冲击强度下降了2.63 kJ/m2;PLA含量的增加使断面逐渐粗糙;在打印效果上复合材料的打印模型随PLA含量的增加而变得美观规整,当底板温度高于110 ℃时,打印制件的翘曲度较低,同时拉伸强度随着打印温度的升高而增加。     

柠檬酸三乙酯改性聚(3-羟基丁酸酯-co-4-羟基丁酸酯)的性能研究

用熔融模压法制备了柠檬酸三乙酯（TEC）增塑的4HB含量不同的聚（3-羟基丁酸酯-co-4-羟基丁酸酯）[P（3HB-co-4HB）]共混物，用差示扫描量热仪（DSC）、广角X射线衍射仪（WAXI））和拉伸试验对共混物的热性能、结晶结构和力学性能进行了表征，考察了增塑剂TEC的用量和4HB含量对共聚酯性能的影响。结果表明：随着TEC用量的增大，P（3HB—co-17％4HB）共聚酯体系的结晶度减小，其熔融温度、玻璃化温度和结晶温度降低，屈服强度、断裂强度及模量也降低，屈服伸长率增大；随4HB含量的增大，相同用量的TEC共混体系的熔点、玻璃化温度和结晶温度降低，屈服强度、断裂强度和模量减小。     

PETG/PC合金材料制备及增韧改性

在聚碳酸酯(PC)中通过添加丙烯腈–丁二烯–苯乙烯塑料(ABS)获得共混体系是改善PC耐溶剂性、降低加工温度的常见方式,然而ABS与PC为不相容体系,在实际加工过程中存在一些问题,聚对苯二甲酸乙二醇酯–1,4–环己烷二甲醇酯(PETG)作为一种新型无定型聚酯具备优异的耐溶剂性有望改善这一问题。通过双螺杆挤出机制备了PETG/PC合金材料,研究了PC与PETG的相容性,以及不同配比下该合金的耐溶剂性和力学性能,同时比较了乙烯–丙烯酸甲酯共聚物、热塑性聚氨酯、苯乙烯–乙烯–丁烯–苯乙烯嵌段共聚物、甲基丙烯酸甲酯–丁二烯–苯乙烯三元共聚物(MBS)四种增韧剂对PETG/PC合金的增韧效果。结果表明,不同配比下PETG/PC合金仅存在一个玻璃化转变温度,说明PETG与PC拥有极好的相容性,相比于PC,PETG/PC合金的玻璃化转变温度更低,加工温度更低;随着PC比例的增加,材料的力学性能显著提升,耐溶剂性逐渐下降。当PETG与PC比例为7∶3时,合金的综合性能最优;四种增韧剂中MBS的效果最好,当添加5份MBS时,合金的冲击强度达到65 kJ/m2,优于PC的冲击强度。     

基于FDM的低翘曲玻璃纤维改性ABS粒料的制备与性能

采用玻璃纤维（GF）、苯乙烯-丙烯腈共聚物（SAN）和丙烯腈-丁二烯-苯乙烯共聚物（ABS）制备GF/ABS复合材料，通过工业级熔融沉积成型（FDM）设备打印测试件，探究GF含量、偶联剂、ABS和SAN的质量比对复合材料打印件翘曲率和力学性能的影响。结果表明：随着GF含量的增大，打印件的翘曲率和力学性能逐渐下降。当GF含量为7份时，打印件的翘曲率为2.89%，平行打印方向和垂直打印方向试件的拉伸强度分别为36.32 MPa和30.59 MPa。材料中加入偶联剂，可以进一步降低打印件的翘曲率，提高力学性能。随着SAN含量的增加，打印件的翘曲率逐渐减小，力学性能逐渐提高。当ABS和SAN树脂的质量比为50∶50,GF和偶联剂含量分别为5份和0.5份，打印件的翘曲率降至2.07%；平行打印方向和垂直打印方向试件的拉伸强度分别提高至46.02 MPa和41.53 MPa。     

Investigation of 3D printing strategy on the mechanical performance of coextruded continuous carbon fiber reinforced PETG

Fused filament fabrication (FFF) has been used to create prototypes and functional parts for various applications using plastic filaments. It has also been extended to the use of continuous fibers for reinforcing thermoplastic polymers. This study aims to optimize the deposition design of a coextruded continuous carbon fiber (CCF) composite filament with a polyethylene terephthalate glycol-modified (PETG) filament. The characterizations on the raw materials revealed that the matrix polymer in CCF composite filament had similar physicochemical properties as PETG, and carbon fibers were homogeneously distributed in CCF filament. The effect of raster orientation and shells number on the mechanical properties of non-reinforced and coextruded CCF-reinforced PETG was investigated. The highest mechanical properties were obtained at a raster orientation of 0° for both reinforced and non-reinforced materials. With the increase of raster orientation, Young's modulus and ultimate tensile strength decreased. The presence of shells improved the tensile strength of non-reinforced PETG. For composite samples printed with unreinforced shells, Young's modulus decreased due to decrease in fibers content, and elongation at break and ultimate tensile strength increased. Tomographic observations showed that the mechanical behavior of printed specimens depended on the anisotropy of porosity in printed specimens.     

3D printability of highly ductile poly(ethylene glycol-co-cyclohexane-1,4-dimethanol terephthalate)-EMAA blends

In this work, ionomers were employed to improve the adhesion between 3D printed layers of poly(ethylene glycol-co-cyclohexane-1,4-dimethanol terephthalate) (PETG), a commonly used polymer in 3D printing. The printability, rheology, and mechanical properties of PETG were tailored by incorporating poly(ethylene-co-methacrylic acid) neutralized with sodium (EMAA), a soft ionomer. PETG/EMAA polymer blends were prepared by melt extrusion to yield filaments for 3D fused filament fabrication (FFF) printing in different compositions by weight: 70/30, 50/50, and 30/70. The filaments and 3D printed samples were characterized by scanning electron microscopy, rheological and tensile tests. The results revealed that the interaction between PETG and EMAA favored the production of 3D printed samples with enhanced adhesion of layers, ductility, and toughness compared to neat PETG. Increases of 83.5 times in toughness and 86.4 times in ductility were achieved. The blends 30/70 and 50/50 presented the best printability in terms of adhesion between printed layers and mechanical properties.     

Enhanced mechanical performance of fused filament fabrication copolyester by continuous carbon fiber in-situ reinforcement

As one of the most commonly used thermoplastics, polyester has rarely been used as the raw materials of 3D printing. However, copolyester obtained by copolymerization modifying polyester, such as Poly Ethylene Terephthalate Glycol (PETG), has been proven to be suitable for the fused filament fabrication (FFF) technique in previous studies, but the mechanical performance of printed products is still poor. In this paper, 3D printed PETG is in-situ reinforced by continuous carbon fiber (CCF), and the relationship between the process parameters and the mechanical performance of CCF/PETG is systematically investigated. The results show that the performance of 3D printed PETG is significantly enhanced by CCF in-situ reinforcement due to the effectively impregnation of CCF. By optimizing process parameters, the tensile strength, flexural strength and flexural modulus of CCF/PETG are 597%, 293% and 650% of pure PETG, respectively, with a relatively low fiber mass fraction of 19.2 wt%. This paper demonstrates that CCF in-situ reinforced 3D printed copolyester may be used in the manufacture of complex structural parts that require high mechanical performance in the engineering application.     

3D polymer composite filament development from post-consumer polypropylene and disposable chopstick fillers

This study focused on the development of three-dimensional (3D) polymer composite filament made of disposable chopstick (DC) and post-consumer polypropylene (PPP). The PPP/DC composite parts were printed via fused filament fabrication (FFF) process. The effect of the printing temperature and different DC fiber content on the properties of the 3D printed parts were investigated. The printing temperature of 200–220°C was suitable for these filaments because the printing temperature did not show any thermal degradation, as proven by thermogravimetric analysis. Furthermore, the thermal stability of the 3D filament increased with DC content. The chemical modification with sodium hydroxide (NaOH) was carried out on DC to remove the unwanted organic components by showing changes in peak intensity in the Fourier transform infrared analysis. Moreover, the melt flow index of the composite filaments decreased with increasing of the DC content and caused the composites' viscosity increased. The results show that the optimum printing temperature of 210°C would reduce the warping and gave better tensile properties to the 3D printed parts. Nevertheless, the tensile strength and elongation at break of the 3D printed PPP/DC parts reduced as the DC content increased because the presence of some air gap and fiber pull out on the fracture surface of 3D printed parts, which are in line with the results observed from scanning electron microscopy. However, the tensile strength and elongation at break percentage of all 3D printed PPP/DC composite parts were higher in comparison with the 3D parts printed by commercial wood plastic composite filament.     

Mechanical properties of 3D parts fabricated by fused deposition modeling: Effect of various fillers in polylactide

Weak mechanical strength and serious mechanical anisotropy are two key limiting factors for three-dimensional (3D) parts prepared by fused deposition modeling (FDM) in industrial applications. In this work, we investigated the relationships between mechanical properties and surface quality of FDM parts with the properties of materials used. Three kinds of polylactide (PLA) filaments, composed of the same PLA matrix but different fillers (carbon fibers and talc), were used to prepare FDM specimens. Due to the nature of FDM process, FDM parts exhibited tensile properties weaker and more anisotropic than their injection-molding counterparts. The presence of fillers affected the tensile properties of FDM parts, especially the degree of mechanical anisotropy. It is found that the interlayer bond governing the mechanical performance of FDM parts was improved since the fillers added in the polymer materials facilitates the molecular diffusion across the bond interface. Also, the surface quality of FDM parts varied with fillers. Neat PLA parts exhibited surface quality superior to the 3D parts printed with composites filaments. This work is believed to provide highlights on the development of polymer composites filament and improvement of mechanical properties of FDM parts. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47824.     

Thermal and mechanical properties of polyamide 12/graphene nanoplatelets nanocomposites and parts fabricated by fused deposition modeling

The printable polyamide 12 (PA12) nanocomposite filaments with 6 wt % graphene nanoplatelets (GNPs) for fused deposition modeling (FDM) were prepared by melting compounding and smoothly printed via a commercial FDM three‐dimensional (3D) printer. The thermal conductivity (λ) and elastic modulus (E) of 3D printed PA12/GNPs parts along to the printing direction had an increase by 51.4% and 7% than that of compression molded parts, which is due to the GNPs preferentially aligning along to the printing direction. Along with these improved properties, ultimate tensile strength of 3D printed PA12/GNPs parts was well maintained. These results indicate that FDM is a new way to achieve PA12/GNPs parts with enhanced λ over compression moulding, which could contribute to realize efficient and flexible heat management for a wide range of applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45332.     

An Experimental Study of Nozzle Temperature and Heat Treatment (Annealing) Effects on Mechanical Properties of High-Temperature Polylactic Acid in Fused Deposition Modeling

Fused deposition modeling (FDM) is the trendiest three-dimensional (3D) printing method among additive manufacturing technologies. In this process, the final parts are constructed through layer-by-layer adhesion of thermoplastic polymers. Amorphous thermoplastic polymers have better printability compared to semicrystalline ones; so, they are most popular with FDM users. Generally, the overall mechanical properties of FDM 3D printed parts are weaker in comparison to the traditional methods (such as injection molding) due to the weak bonds between the deposited rasters and layers. Therefore, the introduction of new materials with higher mechanical properties and easy printing process of the semicrystalline polymers has always been challenging to progress the mechanical properties of the products. In this study by the FDM process, the effect of nozzle temperature and heat treatment (annealing) on the mechanical properties of high-temperature polylactic acids is investigated. The increase in the nozzle temperature develops the rasters and layers bonding, and the heat treatment of the parts after printing rises the crystallinity percentage, which is crucial for the improvement of mechanical properties. Experimental results show that an increase in the nozzle temperature raises the tensile strength and modulus to 65.7 MPa and 4.97 GPa, respectively. Furthermore, the heat treatment process increases the tensile strength and modulus up to 67.4 MPa and 5.65 GPa. The final tensile modulus values are the highest ones reported for pure materials printed by the FDM process. POLYM. ENG. SCI., 60:979–987, 2020. © 2020 Society of Plastics Engineers     

Improved part strength for the fused deposition 3D printing technique by chemical modification of polylactic acid

Fused deposition method (FDM) is popular as a plastic 3D printing technique. One of the drawbacks of this technology is its low bonding strength between layers, reducing through‐plane mechanical properties of a part compared with in‐plane strength within the layers themselves. This study focuses on altering the molecular structure of a polylactic acid by chain extension to increase the adhesion strength between layers, quantified by peel testing, in order to increase overall part strength. Four different samples were prepared in a high shear mixer, processed into filament and printed by a FDM‐type 3D printer. These samples were characterized for their thermal, rheological, mechanical and adhesion properties. The findings showed that the chain extender‐modified resins exhibited higher layer‐to‐layer adhesion strength as well as increased viscosity corresponding to an increasing degree of branching. The interlayer diffusion and entanglement of newly created branch chain ends improved bonding between the printed layers resulting in higher tensile properties. POLYM. ENG. SCI., 59:E59–E64, 2019. © 2018 Society of Plastics Engineers     

Effect of printing temperature on microstructure,thermal behavior and tensile properties of 3D printed nylon using fused deposition modeling

The present investigation aims at the thermal conditions for the printability of nylon using fused deposition modeling (FDM). Dog-bone like specimens are manufactured under two printing temperatures to measure the tensile performance of 3D printed nylon with respect to the feedstock material properties. Both Scanning Electron Microscopy (SEM) and X-ray micro-tomography analysis are conducted to shed more light on the microstructural arrangement of nylon filaments. Finite element computation based on microstructural implementation is considered to study the main deformation mechanisms associated with the nylon filament arrangement and the process-induced porosity. The results show a narrow temperature range for printability of nylon, and a significant influence of the printing temperature on the thermal cycling, porosity content and mechanical performance. With the support of both numerical and experimental results, complex deformation mechanisms are revealed involving shearing related to the filament sequencing, compression at the junction points and tension within the raster and the frame. All these mechanisms are associated with the particular and regular arrangement of nylon filaments.