Synthesis and characterization of porous polyimide films containing benzimidazole moieties

2017 ◽  
Vol 29 (7) ◽  
pp. 869-876 ◽  
Author(s):  
Jianwei Li ◽  
Guangcheng Zhang ◽  
Zhanxin Jing ◽  
Jiantong Li ◽  
Lisheng Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Mechanical And Thermal Properties ◽  
Size Distributions ◽  
Porous Films ◽  
Polyimide Films ◽  
Molar Ratios ◽  
Phase Separation Process ◽  
Cell Size Distributions

In this study, a series of porous polyimide films containing benzimidazole units were prepared through a phase separation process. The dibutyl phthalate was selected as porogen. The copolyimides were prepared by the reaction of 3,3′,4,4′-benzophenonetetracarboxylic dianhydride with two diamines of 2-(4-aminophenyl)-5-aminobenzimidazole (BIA) and 4,4′-diaminodiphenyl ether with various molar ratios. The resultant porous polyimide films exhibit optimum cell-size distributions. The effects of BIA on morphology, mechanical, and thermal properties of the porous films were explored. It was found that as the BIA content reached up to 30 mol%, the porous copolyimide film demonstrates remarkable thermal stability and admirable mechanical properties with the glass transition temperature of 294°C, 5% weight loss temperature in argon flow up to 545°C, and a tensile strength of 48 MPa. The incorporation of BIA into the polyimide chains brought the highly rigid structures and strong intermolecular interactions, resulting in the enhancement in the thermal stability and the mechanical properties.

scholarly journals Enhancement of Oil Palm Waste Nanoparticles on the Properties and Characterization of Hybrid Plywood Biocomposites

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1007 ◽  
Author(s):  
Arif Nuryawan ◽  
C. Abdullah ◽  
Che Hazwan ◽  
N. Olaiya ◽  
Esam Yahya ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Oil Palm ◽  
Phenol Formaldehyde ◽  
Morphological Properties ◽  
Mechanical And Thermal Properties ◽  
Empty Fruit Bunch ◽  
Oil Palm Trunk ◽  
Stability Performance ◽  
Properties And Characterization

Using oil palm trunk (OPT) layered with empty fruit bunch (EFB), so-called hybrid plywood enhanced with palm oil ash nanoparticles, with phenol-formaldehyde (PF) resin as a binder, was produced in this study. The phenol-formaldehyde (PF) resins filled with different loading of oil palm ash (OPA) nanoparticles were prepared and used as glue for layers of the oil palm trunk (OPT) veneer and empty fruit bunch fibre mat. The resulting hybrid plywood produced was characterised. The physical, mechanical, thermal, and morphological properties of the hybrid plywood panels were investigated. The results obtained showed that the presence of OPA nanoparticles significantly affected the physical, mechanical, and thermal properties of the plywood panels. Significant improvements in dimension from water absorption and thickness swelling experiments were obtained for the plywood panels with the highest OPA nanoparticles loading in PF resin. The mechanical properties indicated that plywood composites showed improvement in flexural, shear, and impact properties until a certain loading of OPA nanoparticles in PF resin. Fracture surface morphology also showed the effectiveness of OPA nanoparticles in the reduction of layer breakage due to force and stress distribution. The thermal stability performance showed that PF filled OPA nanoparticles contributed to the thermal stability of the plywood panels. Therefore, the results obtained in this study showed that OPA nanoparticles certainly improved the characteristic of the hybrid plywood.

scholarly journals Development of Photocrosslinkable Urethane-Doped Polyester Elastomers for Soft Tissue Engineering

2011 ◽  
Vol 1 (1) ◽  
pp. 18-31 ◽  
Author(s):  
Yi Zhang ◽  
Richard T. Tran ◽  
Dipendra Gyawali ◽  
Jian Yang
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Soft Tissue ◽  
Hexamethylene Diisocyanate ◽  
Elongation At Break ◽  
Thermally Induced ◽  
Molar Ratios ◽  
3D Network ◽  
Soft Tissue Engineering

Finding an ideal biomaterial with the proper mechanical properties and biocompatibility has been of intense focus in the field of soft tissue engineering. This paper reports on the synthesis and characterization of a novel crosslinked urethane-doped polyester elastomer (CUPOMC), which was synthesized by reacting a previously developed photocrosslinkable poly (octamethylene maleate citrate) (POMC) prepolymers (pre-POMC) with 1,6-hexamethylene diisocyanate (HDI) followed by thermo- or photo-crosslinking polymerization. The mechanical properties of the CUPOMCs can be tuned by controlling the molar ratios of pre-POMC monomers, and the ratio between the prepolymer and HDI. CUPOMCs can be crosslinked into a 3D network through polycondensation or free radical polymerization reactions. The tensile strength and elongation at break of CUPOMC synthesized under the known conditions range from 0.73±0.12MPa to 10.91±0.64MPa and from 72.91±9.09% to 300.41±21.99% respectively. Preliminary biocompatibility tests demonstrated that CUPOMCs support cell adhesion and proliferation. Unlike the pre-polymers of other crosslinked elastomers, CUPOMC pre-polymers possess great processability demonstrated by scaffold fabrication via a thermally induced phase separation method. The dual crosslinking methods for CUPOMC pre-polymers should enhance the versatile processability of the CUPOMC used in various conditions. Development of CUPOMC should expand the choices of available biodegradable elastomers for various biomedical applications such as soft tissue engineering.

Preparation and characterization of surface modified boron nitride epoxy composites with enhanced thermal conductivity

RSC Advances ◽  
2014 ◽  
Vol 4 (83) ◽  
pp. 44282-44290 ◽  
Author(s):  
Jun Hou ◽  
Guohua Li ◽  
Na Yang ◽  
Lili Qin ◽  
Maryam E. Grami ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Boron Nitride ◽  
High Thermal Conductivity ◽  
Epoxy Composites ◽  
Surface Modified ◽  
Enhanced Thermal Conductivity ◽  
Electrical Insulation Properties

The fabricated surface modified boron nitride epoxy composites exhibit high thermal conductivity, superior thermal stability and good mechanical properties while retaining good electrical insulation properties.

Characterization of kaolinite/styrene butadiene rubber composite: Mechanical properties and thermal stability

2016 ◽  
Vol 124-125 ◽  
pp. 167-174 ◽  
Author(s):  
Yinmin Zhang ◽  
Qinfu Liu ◽  
Shilong Zhang ◽  
Yude Zhang ◽  
Yongfeng Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Rubber Composite ◽  
Styrene Butadiene

Mechanical and Thermal Properties of PLA Melt Blended with High Molecular Weight PEG Modified with Peroxide and Organo-Clay

2017 ◽  
Vol 751 ◽  
pp. 337-343 ◽  
Author(s):  
Chanchai Thongpina ◽  
Chaiwat Tippuwanan ◽  
Kwanchai Buaksuntear ◽  
Teerani Chuawittayawuta
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Mechanical Performance ◽  
Organic Peroxide ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Cloisite 30B

The thermal and mechanical properties of poly (lactic acid) blended with high molecular weight PEG, i.e. PEG1000 and PEG6000 were compared. The contents of PEG added were 10, 12.5 and 15 % by weight, with respect to PLA. The PLA/PEG blends were modified by addition of organic peroxide in order to induced crosslinking. Addition of organic modified montmorrillonite (Cloisite 30B, C30B) was also performed in order to modify mechanical performance of PLA/PEG blends. C30B was prepared via master batch in PLA. Morphology, crystallization, thermal stability and mechanical properties of the blends were investigated using SEM, DSC, TGA and universal testing macine, respectively. Morphology of cryogenic fracture surface showed smooth brittle surface. PEG1000 well plasticized PLA where as PEG6000 shows better thermal stability and mechanical properties. The presence of PEG induced PLA to perform cold crystallization. Tm in PLA was slightly changed whereas degree of crystallinity of PLA was improved by PEG but slightly decreased by peroxide. The thermal stability of PLA was enhanced with the addtion of PEG6000. The toughening of PLA was confirmed by the increment of elongation at break. The exfoliation of C30B was interfered by the crosslink PLA. Then tensile strength of PLA/PEG/C30B/Luperox101 was then suppressed. The optimum properties, in term of toughening and thermal stability, were found at PEG content of 10 % rather than 15% by weight, for both PEG1000 and PEG6000.

Clay modification with silane compounds and characterization of the silicone rubber/clay composites

2012 ◽  
Vol 32 (8-9) ◽  
pp. 493-502 ◽  
Author(s):  
Kyeong Hoon Jang ◽  
Eung-Soo Kim ◽  
Young Ho Jeon ◽  
Jin-San Yoon
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Silicone Rubber ◽  
Cross Linking ◽  
Mechanical And Thermal Properties ◽  
Curing Agent ◽  
Thiol Groups ◽  
Rubber Composites ◽  
Clay Modification

Abstract Na+ montmorillonite (MMT) was modified with benzyldimethyltetradecylammonium chloride (B13) and further with (3-mercaptopropyl)triethoxysilane and vinyltrimethoxysilane to prepare B13-MMT, mercaptomethylorthosilicate modified MMT (MTMO), and vinyltrimethoxysilane modified MMT (VTMO), respectively. The pristine and modified clays were compounded with an HTV-type silicone rubber (GP-30®), and the physical properties and morphology of the resulting rubber composites were examined. Both HTV/MTMO and HTV/VTMO exhibited an intercalated/exfoliated coexisting morphology, but the degree of exfoliation of the former composite was higher than that of the latter. Moreover, the thermal stability, as assessed by the onset temperature of thermal degradation, as well as the tensile stress, elongation at the break, and tear strength of HTV/MTMO was higher than those of HTV/B13-MMT and HTV/VTMO. However, the cross-linking density of HTV/MTMO was the lowest among the composites examined because the thiol groups of MTMO extinguished and abstracted the radicals formed by the curing agent. Accordingly, the improved mechanical and thermal properties of HTV/MTMO were attributed to the enhanced interactions between HTV and MTMO due to the chemical reaction between the thiol groups of MTMO and the vinyl groups of HTV.

Dispersion, mechanical and thermal properties of nano graphite platelets reinforced flouroelastomer composites

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Deng Xu ◽  
V. Sridhar ◽  
Thanh Tu Pham ◽  
Jin Kuk Kim
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Thermogravimetric Analysis ◽  
Fracture Surface ◽  
Exfoliated Graphite ◽  
Mechanical And Thermal Properties ◽  
Reinforcing Fillers ◽  
Processing Of Composites

AbstractThe potential of exfoliated graphite nano platelets (xGnP™) as reinforcing fillers in flouroelastomer has been investigated. The dispersion of the nano graphite platelets in the polymer matrix has been investigated by WAXD, SEM, TEM, EPMA and AFM. WAXD studies indicated that the processing of composites did not change the inter-gallery distance (d-spacing) of the graphite platelets. The effect of increasing nano graphite loadings on mechanical properties like tensile strength, modulus and tear resistance has been studied. Formation of weld lines on the fracture surface of the composite has been observed by SEM. The thermal stability was determined using thermogravimetric analysis. The composites showed higher thermal stability in comparison with nonreinforced polymer.

Synthesis and characterization of a phosphorus-containing flame retardant with double bonds and its application in bismaleimide resins

RSC Advances ◽  
2015 ◽  
Vol 5 (123) ◽  
pp. 101480-101486 ◽  
Author(s):  
Song Li ◽  
Hongxia Yan ◽  
Shuyao Feng ◽  
Song Niu
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Synthesis And Characterization ◽  
Bismaleimide Resin ◽  
Phosphorus Containing ◽  
Reactive Phosphorus ◽  
Bismaleimide Resins

A novel reactive phosphorus-containing flame retardant was synthesized and used to modify bismaleimide resin. According to investigations, the modified bismaleimide resin has good mechanical properties, thermal stability and flame retardancy.

Synthesis and characterization of alicyclic two-component waterborne polyurethane

2018 ◽  
Vol 47 (4) ◽  
pp. 315-322 ◽  
Author(s):  
Jizhi Zhang ◽  
Xiankai Jiang
Keyword(s):  
Thermal Stability ◽  
Water Resistance ◽  
Aqueous Dispersion ◽  
Waterborne Polyurethane ◽  
Molar Ratio ◽  
Mechanical And Thermal Properties ◽  
Content Type ◽  
Two Component ◽  
Practical Implications

Purpose The purpose of this paper is to synthesize and characterize a series of alicyclic two-component waterborne polyurethane (2K-WPU) which is composed of non-ionic polyisocyanate aqueous dispersion and hydroxyl aqueous dispersion. Design/methodology/approach The appearances of aqueous dispersions and 2K-WPU films were observed by photographs. The micromorphology of alicyclic polyisocyanate aqueous dispersion was examined by scanning electron microscopy (SEM). The molecule structures of WPU were studied by Fourier transform infrared (FTIR). The effect of NCO:OH molar ratio of two components and trimethylolpropane (TMP) content on the thermal stability, mechanical and water resistance properties of 2K-WPU films was studied. Findings It was found by SEM that alicyclic polyisocyanate particles in aqueous dispersion showed a kind of spherical particle appearance, in which hydrophobic polyisocyanate was encapsulated by hydrophilic ether linkages segment. FTIR showed that WPU was polymerized through mixture of polyisocyanate component and hydroxyl component and increasing NCO:OH molar ratio of two components from 1.1:1 to 1.5:1 had increased the content of urea, urethane and allophanate of 2K-WPU films. Increasing NCO:OH molar ratio had improved the mechanical and thermal properties of the 2K-WPU film, but the water resistance of the 2K-WPU film increased first and then weakened. Increasing TMP contents from 1 to 0.75 mol for 1:5 system had improved the mechanical, thermal and water resistance properties of the 2K-WPU film. Practical implications The investigation established a method to prepare alicyclic 2K-WPU which is composed of non-ionic polyisocyanate aqueous dispersion and hydroxyl aqueous dispersion. The prepared 2K-WPU film could be applied in the field of waterborne surface coating, e.g. textile, wood and synthetic leather surfaces (Hasan et al., 2017; Akindoyo et al., 2016). Originality/value The paper established a method to synthesize alicyclic two-component 2K-WPU. The effect of NCO:OH molar ratio and TMP content on the thermal stability, mechanical and water resistance properties of 2K-WPU films were studied.

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