The Influence of Recycling On Thermotropic Liquid Crystalline Polymer and Glass Fiber Composites

2021 ◽  
Author(s):  
Tianran Chen
Keyword(s):  
High Performance ◽  
Liquid Crystalline ◽  
Tensile Modulus ◽  
Crystalline Polymer ◽  
Fiber Composites ◽  
Reinforced Composites ◽  
Recycling Process ◽  
Mechanical Recycling ◽  
Glass Fiber Composites ◽  
Pp Composites

In this paper, high-performance thermotropic liquidcrystalline polymer (TLCP)/polypropylene (PP) and glassfiber (GF)/PP composites were prepared by the injectionmolding process. Mechanical recycling of TLCP/PP andGF/PP composites consisted of grinding of the injectionmolded specimens and further injection molding of thegranules. The influence of mechanical recycling onmechanical and thermal properties was investigated. In situTLCP/PP maintains tensile modulus and strength duringthe recycling process, indicating the regeneration ofpolymeric fibrils at each reprocessing stage. GF/PPcomposite exhibits deterioration of mechanical propertiesafter recycling because of fiber breakage during processing,which is a very common issue on reusing glass or carbonfiber reinforced composites. The experimental resultsreveal that the TLCP/PP composite has better recyclabilitythan GF/PP.

Morphology of High-Performance Rigid-Rod Polymer Fibers and Molecular Composites

1989 ◽  
Vol 47 ◽  
pp. 338-339
Author(s):  
W.W. Adams ◽  
S. J. Krause
Keyword(s):  
Tensile Strength ◽  
High Performance ◽  
Liquid Crystalline ◽  
Molecular Level ◽  
Synergistic Effects ◽  
Tensile Modulus ◽  
Commercial Development ◽  
The Matrix ◽  
Molecular Composites ◽  
Rigid Rod

Rigid-rod polymers such as PBO, poly(paraphenylene benzobisoxazole), Figure 1a, are now in commercial development for use as high-performance fibers and for reinforcement at the molecular level in molecular composites. Spinning of liquid crystalline polyphosphoric acid solutions of PBO, followed by washing, drying, and tension heat treatment produces fibers which have the following properties: density of 1.59 g/cm3; tensile strength of 820 kpsi; tensile modulus of 52 Mpsi; compressive strength of 50 kpsi; they are electrically insulating; they do not absorb moisture; and they are insensitive to radiation, including ultraviolet. Since the chain modulus of PBO is estimated to be 730 GPa, the high stiffness also affords the opportunity to reinforce a flexible coil polymer at the molecular level, in analogy to a chopped fiber reinforced composite. The objectives of the molecular composite concept are to eliminate the thermal expansion coefficient mismatch between the fiber and the matrix, as occurs in conventional composites, to eliminate the interface between the fiber and the matrix, and, hopefully, to obtain synergistic effects from the exceptional stiffness of the rigid-rod molecule. These expectations have been confirmed in the case of blending rigid-rod PBZT, poly(paraphenylene benzobisthiazole), Figure 1b, with stiff-chain ABPBI, poly 2,5(6) benzimidazole, Fig. 1c A film with 30% PBZT/70% ABPBI had tensile strength 190 kpsi and tensile modulus of 13 Mpsi when solution spun from a 3% methane sulfonic acid solution into a film. The modulus, as predicted by rule of mixtures, for a film with this composition and with planar isotropic orientation, should be 16 Mpsi. The experimental value is 80% of the theoretical value indicating that the concept of a molecular composite is valid.

Photochemistry of Azobenzene Side-Chains Liquid Crystalline Containing Pendant Polyhedral Oligomeric Silsequioxanes (POSS)

2013 ◽  
Vol 721 ◽  
pp. 316-319
Author(s):  
Xiao Tao Wang ◽  
Xiao Tie Ye ◽  
Zhen Hua Li ◽  
Zui Fang Liu
Keyword(s):  
Thermal Stability ◽  
Rate Constant ◽  
High Performance ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Crystalline Polymer ◽  
Liquid Crystalline Polymers ◽  
Side Chains ◽  
Crystalline Polymers ◽  
First Order

Liquid crystalline polymer (LCP) and the copolymer of LCOand Pendant Polyhedral Oligomeric Silsequioxanes (LCP-POSS) showed the first-order photoisomerization reaction. As compared with LCP, the photoisomerization rate constant of LCP-POSS decreased a little. With a higher thermal stability and more stable LC behavior as well as a little decreased photoisomerization rate constant, the incorporation of POSS to azobenzene liquid crystalline polymers may have significant sense and will definitely play a key role in developing novel high-performance optic and photonic nanodevices.

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

Investigation on Improvement of Mechanical Properties of Kenaf / E-Glass Fiber Composites by Mercerization Process

2011 ◽  
Vol 471-472 ◽  
pp. 227-232 ◽  
Author(s):  
Abdul Malek Ya’acob ◽  
Azhar Abu Bakar ◽  
Hanafi Ismail ◽  
Dahlan Khairul Mohd. Zaman
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Hybrid Composites ◽  
Weight Ratio ◽  
Fiber Composites ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Kenaf Fiber ◽  
Glass Fiber Composites

A hybrid composites mechanical properties consisting of un-treated and treated bast Kenaf fiber and E- glass fiber was investigated by varying the fiber glass weight ratio and using interplay fabrication method. A further comparison was made with corresponding properties of 100% wt E-glass fiber composites sample. The expected results were to have better composites performance in terms of toughness and impact strength as a comparison between the E- glass fiber reinforced composites and Kenaf fiber reinforced composites alone. All samples are prepared using typical samples preparation techniques. Result shows that the incorporation of E – glass fiber resulted in brittle failure and a higher amount of E-Glass fiber with low percentage of Kenaf fiber resulted in high strength, low ductile and low toughness behavior.

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