Synthesis and Characterization of Thermotropic Liquid Crystalline Polyesters/Glass Fiber by In Situ Process

2009 ◽  
Vol 79-82 ◽  
pp. 1435-1438
Author(s):  
Chuan Ji Zhang ◽  
Zhi Xiong Huang
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Optical Microscopy ◽  
Liquid Crystalline ◽  
Mechanical Test ◽  
Fiber Type ◽  
Fiber Content ◽  
Synthesis Process ◽  
Processing Mode ◽  
Mesogenic Unit

Liquid crystalline polyesters containing central biphenylene moiety in the mesogenic unit with ester linkages to the different lengths of flexible spacers were synthesized using melt polycondensation reaction. Glass fiber, as a reinforce, was meltpolymerized with 4-acetoxybenzoic(ABA),4,4＇-diacetoxybiphenyl and terephthalic acid(TA) to make TLCPs with a good mechanical properties. All the obtained compounds were characterized by conventional spectroscopic methods. The thermal behavior of the polymers has been characterized using polarized optical microscopy and differential scanning calorimetry. The effect of monomer structure and mechanical properties has been investigated on the prepared polyesters and is also compared with that of the analogous polyester by other processing mode. Optical microscopy showed a highly threaded liquid crystalline texture to a high birefringent Schlierene texture characteristic of the nematic phase for all polyesters. DSC experiments were also found in accord with mesophase formation. The melting points of polymers having a central 4,4’-biphenyldicarboxylate residue have two broad endotherms. The glass transition temperature values of polyesters are not effect by the glass fiber. According to the SEM result showed that the composite had strong fiber-matrix adhesion. From the mechanical test result, it showed that TLCP are reinforced by rigid fiber further improvement of properties depending on fiber content, fiber fabric construction, fiber type. The mechanical properties of GF/TLCP had been improved greatly as the content of glass fiber was increased,but GF/TLCP mechanical properties do not improve remarkably as glass fiber content more than 30wt%.The effect of copolymerization with added glass fiber in synthesis process is compared with that of the anlogous homopolyesters by other processing mode. Our finding shows that the copolymers exhibit reduced technical process and maintained mechanical properties.

Two New Thermotropic Liquid Crystalline Polyesters and their Composites: Synthesis and Characterization

2009 ◽  
Vol 87-88 ◽  
pp. 154-159
Author(s):  
Chuan Ji Zhang ◽  
Zhi Xiong Huang ◽  
Min Xian Shi ◽  
Ming Zhang
Keyword(s):  
Mechanical Properties ◽  
Liquid Crystalline ◽  
Synthesis Process ◽  
Differential Scanning Calorimetric ◽  
Melting Points ◽  
Texture Characteristic ◽  
Scanning Calorimetry ◽  
Heating And Cooling ◽  
Melt Polycondensation ◽  
Monomer Structure

Two new series of liquid crystalline polyesters were synthesized using melt polycondensation reaction.Glass fiber,as a reinforcement,was meltpolymerized with 4-acetoxybenzoic(ABA),4,4＇-diacetoxybiphenyl, isophthalic acid(IA) and terephthalic acid(TA) to make TLCP/GF composites with a good mechanical properties.All the obtained compounds were characterized by conventional spectroscopic methods. The structure of the target compounds and intermediates was conformed by the IR, 1H NMR and SEM. The thermal behavior of the polymers has been characterized using polarized optical microscopy and differential scanning calorimetry. The effect of monomer structure and mechanical properties has been investigated on the prepared polyesters. These compounds show a high birefringent Schlierene texture characteristic of the nematic phase on heating and cooling experiments. This was further confirmed using differential scanning calorimetric investigations.The melting points of polymers having a central 4,4’-biphenyldicarboxylate residue have broad endotherms. The glass transition temperature values of polyesters are not effect by the glass fiber.According to the SEM result showed that the composite had strong fiber-matrix adhesion.The effect of copolymerization with added glass fiber in synthesis process is compared with that of the anlogous homopolyesters by other processing mode.Our finding shows that the copolymers exhibit reduced technical process and maintained mechanical properties.

Preparation and Characterization of TiO2 Particulate Filled Polyester Based Glass Fiber Reinforced Polymer Composite

2014 ◽  
Vol 984-985 ◽  
pp. 360-366 ◽  
Author(s):  
S. Srinivasa Moorthy ◽  
K. Manonmani ◽  
M. Sankar Kumar
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Chemical Resistance ◽  
Fiber Content ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Gfrp Composites ◽  
Glass Fiber Reinforced Polymer ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced

Polyester based glass fiber reinforced polymer (GFRP) composites are widely used in marine and automotive industries because of its strength to weight ratio with lower price. In order to have the better properties of GFRP composites, the particulate filler material titanium oxide (TiO2) was added in unsaturated polyester resin with the fiber reinforcement by hand lay-up process. The fiber content was kept at 35 wt% constant with the fiber length of 5 cm. The particulate was varied with 2 wt. %, 4 wt. %, 6 wt. %, 8 wt. %, and 10 wt. %. Experiments were carried out to study the mechanical properties like tensile strength, impact strength, and Rockwell hardness. The chemical resistance analysis (CRA) was carried out by weight loss method. The mechanical properties of the hybrid reinforced composites were improved due to the fiber content with increased particulate content. The influence of the particulate content was more pronounced in the chemical resistance.

Mechanical properties of glass fiber composites with an epoxy resin modified by a liquid crystalline epoxy

2002 ◽  
Vol 23 (4) ◽  
pp. 564-573 ◽  
Author(s):  
Prakaipetch Punchaipetch ◽  
Nandika Anne D'Souza ◽  
Witold Brostow ◽  
James T. Smith
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Epoxy Resin ◽  
Liquid Crystalline ◽  
Fiber Composites ◽  
Glass Fiber Composites ◽  
Liquid Crystalline Epoxy

The Studying on the Influence of Coupling Agents to Short Glass Fiber Reinforced Polyamide Composites

2011 ◽  
Vol 181-182 ◽  
pp. 836-841
Author(s):  
Jiang Liu ◽  
Xiang Guo Liu
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Fiber Content ◽  
Coupling Agents ◽  
Fiber Reinforced ◽  
Short Glass Fiber ◽  
Glass Fiber Reinforced ◽  
Twin Screws ◽  
Short Glass ◽  
Better Than

Influence of coupling agents on microstructure and mechanical properties of short glass fiber reinforced PA66 composites(SGF/PA66) were investigated by using twin screws extruder and injection machine in this paper. When coupling agents (A1100 or A1100+A+B) were added, short glass fiber was distributed in the PA66 matrix more homogeneously; at the same time, the microstructure and properties of GF/PA66 were improved too. Modified effect of multiple coupling agent (A1100+A+B) is better than that of only A1100 and the desired content of A1100 is about 1.5~2.0wt%. When glass fiber content was less than the critical value (35~40%), mechanical properties of PA composites increase with fiber content increasing, but it begin to decrease when content was excess that value. At last, Failure mechanism of GF/PA66 (treated by A1100 or A1100+A+B) was obtained: adhesion of interface between glass fiber and PA66 matrix, friction after the adhesion, glass fiber pullouted and matrix failure.

scholarly journals Injection Molding of Wood-Filled Thermoplastic Polyurethane

2021 ◽  
Vol 5 (12) ◽  
pp. 316
Author(s):  
Elmar Moritzer ◽  
Maximilian Richters
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Temperature Control ◽  
Fiber Type ◽  
Wood Fiber ◽  
Region Of Interest ◽  
Fiber Reinforcement ◽  
Fiber Content ◽  
Shore Hardness ◽  
Product Price

Wood fiber reinforcement of plastics is almost limited to polypropylene, polyethylene, polyvinyl chloride and polystyrene. Wood fiber reinforcement of thermoplastic polyurethanes (TPU) is a new research field and paltry studied scientifically. Wood fiber reinforcement can carry out synergistic effects between sustainability, material or product price reduction, improved mechanical properties at high elongation, and brilliant appearance and haptics. In order to evaluate to what extent the improvement of mechanical properties depend on material-specific parameters (fiber type, fiber content) and on process-specific parameters (holding pressure, temperature control and injection speed), differently filled compounds were injection molded according to a partial factorial test plan and subjected to characterizing test procedures (tensile test, Shore hardness and notched impact test). Tensile strength showed significant dependence on barrel temperature, fiber type and interaction between holding pressure and barrel temperature in the region of interest. Young’s modulus can be influenced by fiber content but not by fiber type. Notched impact strength showed a significant influence of cylinder temperature, fiber content, fiber type and the interaction between cylinder temperature and fiber content in the region of interest. Shore hardness is related to fiber content and the interaction between mold temperature and injection flow rate. Our results show not only that wood-filled TPU can be processed very well by injection molding, but also that the mechanical properties depend significantly on temperature control in the injection-molding process. Moreover, considering the significant reinforcing effect of the wood fibers, a good fiber-matrix adhesion can be assumed.

scholarly journals Thermal Aging of Unsaturated Polyester Composite Reinforced with E-Glass Nonwoven Mat

2017 ◽  
Vol 17 (4) ◽  
pp. 313-318 ◽  
Author(s):  
Milon Hossain ◽  
A.H.M Fazle Elahi ◽  
Shahida Afrin ◽  
Iqbal Mahmud ◽  
Haeng Muk Cho ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Prolonged Exposure ◽  
Mechanical Test ◽  
Unsaturated Polyester ◽  
Heat Exposure ◽  
Polymeric Composite ◽  
Heat Treated Sample ◽  
Glass Fiber Reinforced ◽  
Polyester Composite

Abstract An experiment was carried out using glass fiber (GF) as reinforcing materials with unsaturated polyester matrix to fabricate composite by hand layup technique. Four layers of GF were impregnated by polyester resin and pressed under a load of 5 kg for 20 hours. The prepared composite samples were treated by prolonged exposure to heat for 1 hour at 60-150°C and compared with untreated GF-polyester composite. Different mechanical test of the fabricated composite were investigated. The experiment depicted significant improvement in the mechanical properties of the fabricated composite resulted from the heat treatment. The maximum tensile strength of 200.6 MPa is found for 90°C heat-treated sample. The mechanical properties of the composite do seem to be very affected negatively above 100°C. Water uptake of the composite was carried out and thermal stability of the composite was investigated by thermogravimetric analysis, and it was found that the composite is stable up to 600°C. Fourier transform infrared spectroscopy shows the characteristic bond in the composite. Finally, the excellent elevated heat resistant capacity of glass-fiber-reinforced polymeric composite shows the suitability of its application to heat exposure areas such as kitchen furniture materials, marine, and electric board.

Study on Properties of Wollastonite Micro Fiber Reinforced Mortar

2013 ◽  
Vol 785-786 ◽  
pp. 151-156 ◽  
Author(s):  
Xiao Deng ◽  
Wen Yang ◽  
Xiao Qin Liu ◽  
Bao Jun Cheng ◽  
Tong Liu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Glass Fiber ◽  
Comparative Studies ◽  
Cement Hydration ◽  
Three Dimensional ◽  
Sem Analysis ◽  
Fiber Content ◽  
Hydration Products ◽  
Fiber Reinforced

The paper carried out comparative studies on the workability, mechanical properties and chloride permeation resistance of wollastonite micro fiber mortar and alkali resistant glass fiber（ARGF） mortar. The results show that the mechanical properties and chloride permeation resistance of wollastonite micro fiber mortar improve significantly. The mechanical properties of wollastonite micro fiber mortar have greater advance in 90°C humidity. The SEM analysis results show that wollastonite micro fiber can form three-dimensional skeleton in the mortar, and combine closely with cement hydration products. This can make the structure of hardened paste denser and lead to excellent properties of mortar. Meanwhile, the compressive strength of wollastonite micro fiber mortar with wollastonite micro fiber content 30%(by mass) is close to ARGF mortar with ARGF content 1.5% (in volume), but the chloride permeation resistance of wollastonite micro fiber mortar is much better.

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