Polydicyclopentadiene Composites Research Articles

Carbon fibre-reinforced polydicyclopentadiene composites for automobile applications

In this study, two types of carbon fibre (CF)-reinforced polydicyclopentadiene (PDCPD) composites were prepared using CF powder and cloth. The effects of the CF content and curing temperature on the mechanical properties of PDCPD were investigated, and the reinforcement mechanisms were explored from a microstructural perspective. CF cloth-reinforced PDCPD achieved a tensile strength of 405 MPa and bending strength of 213 MPa, which were higher than those of CF powder-reinforced PDCPD. Based on the results, PDCPD composites reinforced with CF powder can be used in automotive exterior trims, whereas PDCPD composites prepared using CF cloth can be used in load-bearing parts of automobiles.

Application of poly(lactic acid)-grafted cellulose nanofibers as both inhibitor and reinforcement for 3D-printable tough polydicyclopentadiene composites via frontal ring-opening metathesis polymerization

Due to the contradiction between curing rate and degree of polymerization, fabrication of 3D-printable thermosetting polymer resin with strong, and tough properties via frontal ring-opening metathesis polymerization (FROMP) remains challenging. Here, poly(lactic acid)-grafted cellulose nanofibers (CNF-g-PLA) was used as both inhibitor and fortifier to prepare 3D printable, strong, and tough polydicyclopentadiene (PDCPD)-based composites by FROMP. When 5 % CNF-g-PLA was added, the fracture toughness and tensile strength of the PDCPD/CNF-g-PLA composites increased by 277.94 % and 12.6 %, respectively. Meanwhile, the rate of radical-induced polymerization was reduced by 106 %, significantly improved the 3D-printability of PDCPD. The two-dimensional (2D) sheet of PDCPD/CNF-g-PLA composites exhibited good flexibility, which could easily be crimped into a cylinder because of CNF-g-PLA contribution. Moreover, owing to the improved toughness, PDCPD/CNF-g-PLA composites can be used as engineering protect materials such as vehicle bumpers, further broadening the application fields of 3D-printed PDCPD/CNF-g-PLA composites. This study provides a feasible method for the application of CNF in 3D printable thermoset resins.

Assessment of Long Fiber Spray-up Molding of Chopped Glass Fiber Reinforced Polydicyclopentadiene Composites

Chopped strands of glass fiber reinforced polymerized dicyclopentadiene (p-DCPD) was manufactured and mechanical properties were assessed. For the purpose, a lab-scale long fiber spray-up molding apparatus had been designed and built. Polydicyclopentadiene (p-DCPD) is a crosslinking polymer with a very rigid network structure resulting excellent mechanical and corrosion resistant properties. In this research, the length of the glass fiber roving was cut such that it would be 100 times its critical length. Uniformity of the fiber volume distribution was examined by varying the spray height, glass fiber weight percentage and the fiber length. Mechanical properties were measured for each processing conditions. It was found that tensile strengths of the specimen fabricated with 50 mm glass fiber were higher over the shorter (25 mm) fiber only if sufficient spray height was achieved. It is definitely desirable to use long strands of chopped glass fibers for composite fabrication processes however; a careful manufacturing precaution is required since the effect of the adhesion force between long fibers from the fiber entanglement cannot be ignored.

Impact and shear properties of carbon fabric/ poly-dicyclopentadiene composites manufactured by vacuum‐assisted resin transfer molding

AbstractDicyclopentadiene (DCPD) resin has gained popularity owing to its fast curing time and ease of processing with a low viscosity in the monomer state. In the present study, the impact and shear properties of a carbon fiber (CF)/p-DCPD composite were investigated. The CF/p-DCPD composite was manufactured by vacuum-assisted resin transfer molding with CF as the reinforcement and p-DCPD as the resin with a maximum fiber volume fraction of 55 weight percent. Impact and shear properties of the CF/p-DCPD composite were evaluated and compared with those of a CF/Epoxy composite. The maximum shear stress and modulus of the CF/p-DCPD composite were lower than that of the CF/Epoxy composite. However, the CF/p-DCPD composite had higher toughness than that of the CF/Epoxy composite; this indicates that it is tougher and exhibits a more ductile load-displacement response with a lower modulus and larger failure deformation. The impact strength of the CF/p-DCPD composite was about three time that of the CF/Epoxy composite. The higher impact strength of the CF/p-DCPD composite is attributed to the resin characteristics: epoxy resin has a more brittle behavior, and hence, higher energy is required for crack propagation due to fracture.

Dramatically enhanced tensile strength and impact toughness of polydicyclopentadiene composites by covalent bond formation between phenyl-functionalized silica and dicyclopentadiene

Enhanced tensile strength and impact toughness of polymers are desirable for their engineering applications through introduction of low loading fine fillers. In this work, dramatically enhanced tensile strength and impact toughness of polydicyclopentadiene (PDCPD) composites are simultaneously achieved by addition of phenyl-functionalized silica (P–SiO2) at low loadings. First, P–SiO2 particles with a uniform size of ca. 600 nm were prepared via a one-step sol-gel process, leading to covalent bond formation between phenyl-functionalized silica and dicyclopentadiene. Then, P–SiO2/PDCPD composites were fabricated by in-situ polymerization, and their tensile and impact properties were investigated. Interestingly, it is observed that the yield strength of the P–SiO2/PDCPD composites was dramatically enhanced by 63% and the notched Izod impact strength (impact toughness) was improved by 217% via addition of 0.3 wt% P–SiO2. Besides these enhancements, the storage modulus and glass transition temperature of PDCPD were also increased by the introduction of silica particles at low loadings. Consequently, it is clear that silica particles with rigid phenyl groups are promising for enhanced strength and toughness of silica/PDCPD composites. Compatibility between PDCPD and P–SiO2 as well as strong covalent bonding between phenyl groups and DCPD are responsible for the dramatic reinforcements of the composite tensile strength and impact toughness, etc.

Dramatic Toughness Enhancement of Polydicyclopentadiene Composites by Incorporating Low Amounts of Vinyl-Functionalized SiO2

A dramatic improvement of the toughness of polydicyclopentadiene (PDCPD) composite containing low amounts of vinyl-functionalized SiO2 was achieved, and the toughening mechanism was investigated. Considering the nonpolarity of the DCPD monomer and the probability of covalent bonding between SiO2 and DCPD, vinyl-functionalized SiO2 (V-SiO2) with a high content of vinyl groups was prepared by a facile, reproducible, one-step, remodeled synthetic sol–gel process. The V-SiO2 was characterized with respect to the content of vinyl groups, particle size, and morphology by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), dynamic light scattering (DLS), and field-emission scanning electron microscopy (FE-SEM). PDCPD/V-SiO2 composites were prepared by in situ polymerization. The mechanical properties of the PDCPD/V-SiO2 composites were investigated by universal testing machine (UTM) and dynamic mechanical analysis (DMA). A slight decrease in the yield strength was observed with incr...

Mechanical properties of norbornene-based silane treated glass fiber reinforced polydicyclopentadiene composites manufactured by the S-RIM process

Abstract A lab scale structural reaction injection molding (S-RIM) piece of equipment was designed and used to fabricate glass fiber reinforced polydicyclopentadiene (p-DCPD) composites for three different fiber contents. In order to obtain information regarding the optimal process temperature (>80°C) and the curing time (<30 s), differential scanning calorimetry (DSC) was used to investigate the curing behavior of DCPD resin under isothermal conditions. Further, a norbornene-based silane treatment was used to improve the interfacial adhesion between the glass fibers and DCPD as confirmed by the micro-droplet pull-out test and scanning electron microscopy (SEM). Fabrication of glass fiber/p-DCPD composites with improved mechanical properties was carried out based on the optimized process conditions and surface treatment of glass fiber.

In situ Formation of Mildly Oxidized Graphene Oxide/Polydicyclopentadiene Composite and Reinforced Mechanical and Thermal Performances

A series of mildly oxidized graphene oxide (MOGO) reinforced polydicyclopentadiene composites (MOGO/polyDCPD) were prepared via the in situ polymerization of DCPD in the presence of MOGO using ring-opening metathesis polymerization (ROMP). The inter-crosslinking networks between MOGO and polyDCPD backbones formed the reinforced composite structures, examined qualitatively by swelling tests. Bending tests, DMA and TGA measurements were employed to study the optimal loading content of MOGO for achieving the best mechanical and thermal properties of MOGO/polyDCPD composites. The results showed that the maximum mechanical performance was achieved with 0.1 wt% of MOGO loading. Excess MOGO led to decreased mechanical properties due to the poor solubility and uneven distribution of MOGO in the polymer matrix, which was confirmed by SEM. Meanwhile, the thermal stability of MOGO/polyDCPD composites showed a similar trend. The decomposition temperature at 10 wt% weight loss was significantly increased compared with the unfilled polyDCPD, but decreased with composition of MOGO above 0.1 wt%. The addition of MOGO may not only inhibit the back-biting from the catalyst and the formation of low molecular weight oligomers in the polymer, but also covalently immobilize them on its flake.

Mechanical properties of polydicyclopentadiene/graphite nanosheet composites prepared by reaction injection moulding

Polydicyclopentadiene (PDCPD)/expanded graphite nanosheets treated with silane coupling agent (TEG) composites were prepared by simulating reaction injection moulding. Studies on the mechanical and tribological properties of the composites were carried out. The results showed that TEG of low content had an effect on reinforcing the PDCPD matrix. The incorporation of TEG in PDCPD greatly decreased wear rates and slightly increased friction coefficients under both dry sliding and oil lubricated conditions. The SEM images of the worn surface revealed their wear mechanisms. Unfilled PDCPD was characterised by spalling, with adhesive wear being the major wear form. Polydicyclopentadiene composites were characterised by plastic deformation, fatigue microcracking, spalling and ploughing effect in dry sliding. The wear forms for PDCPD composites under oil lubricated condition were also complicated, and several wear forms such as adhesive, abrasive and fatigue wears co-existed.