Polyethylene terephthalate flexural modulus

Janik and Krolikowski [53] investigated the effect of Charpy notched impact strength and other mechanical properties such as tensile strength, flexural strength, elastic modulus, flexural modulus, melt viscosity, and fracture on the mechanical and rheological properties of PE-polyethylene terephthalate (PET) blends. 

Janick and Kroliskowski [40] investigated the effect of Charpy notched impact strength on the flexural modulus of polyethylene and polyethylene terephthalate. Polymers with good flexural modulus include polydiallylisophthalate (11.3 GPa), phenol-formaldehyde (6.5 GPa), alkyd resins (8.6 GPa), and polyphenylene sulfide (13.8 GPa), as well as glass-filled polyester laminate (16 GPa) epoxy resins (3-3.5 GPa), sUica-fiUed epoxies (15 GPa), and acetals containing 30% carbon fiber (17.2 GPa). 

With the exception of epoxies and perfluoroalkoxy, the incorporation of 25%-50% glass fiber reinforcement leads to an improvement in flexural modulus. As shown in Table 3.2, the outstanding polymers are polyethylene terephthalate, where... 

Reinforced polymers that combine high tensile strength with high flexural modulus include polybutylene terephthalate, polyether ether ketone, polyamide-imide, and polyethylene terephthalate (see Table 3.3). 

As seen earlier, the incorporation of 30% glass fiber into polyethylene terephthalate increases the tensile strength from 55 to 100 MPa (Table 3.1), while increasing the flexural modulus from 2.3 to 5-17.9 GPa and decreasing the elongation of break from 250% to 2.2% (Table 3.3). 

FIGURE 2.15 Flexure modulus E for epoxy, PES, and PET as a function of temperature determined by the DMA test. (PES, polyether sulfone PET, polyethylene terephthalate.) (From Sepe, M. R, Advanced Materials and Processes Magazine, 4, 32—41, 1992. Reprinted with permission of ASM International.)... 

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