Izod impact strength


Fig. 3. Dependence of Izod impact strength on temperature for (— Fig. 3. Dependence of Izod impact strength on temperature for (—
Izod impact strength, J /m  [c.405]

Izod impact strength at —SO "C, J/m, >640 250 120  [c.271]

The particle size and size distribution are largely controlled by the appHed shear rate during and after phase inversion, the viscosity of the continuous phase, the viscosity ratio of the two phases, and the interfacial tension between the phases (51,202). The viscosity parameters depend on phase compositions, polymer molecular weights, and temperatures the interfacial tension is largely controlled by the amount and stmcture of the graft copolymer available at the particle surface. Phase-contrast micrographs of this phase-inversion sequence, wherein the PS phase is dark, are shown in Figure 27. If shearing agitation is insufficient, then phase inversion does not occur and the product obtained is a network of cross-linked mbber with PS and its properties are much inferior. The morphology of the dispersed mbber phase remains much as formed after phase inversion, unless there is a step change in phase concentration, eg, by blending streams. Rubber-phase volume, including the occlusions, largely controls performance. Izod impact strength depends on mbber particle size and varies from 48 J/m (0.9 ftlbf/in.) at an average particle diameter of 0.6 lm to - 100 J/m (1.9 ftlbf/in.) at 3.5 lm diameter (204).  [c.520]

Izod impact strength. no no 21-213 21-64 varies 18-24 74-640 16-32 750 16-24 64-123  [c.326]

Izod impact strength, J/m 16-80 214-427 240-1500  [c.326]

Izod impact strength at 23°C (ftlbf in D.256 2.0 1.2-1.3 — 3.5 2.9 — —  [c.368]

Izod impact strength ftlbf in- (B.S.) 0.40  [c.406]

Izod impact strength (23 C) D.758 0.4 ft lb per in notch  [c.551]

Izod impact strength ft Ibf per in notch ASTM D.256-56 12-16 15-18 ca 2.5 ca 2.5  [c.568]

Heat aging effects are somewhat complex. Heating at 125°C will cause reduction in elongation at break to 5-15% and in Izod impact strength from 16 down to 1-2 ft Ibf per in notch and a slight increase a tensile strength in less than four days. Further aging has little effect on these properties but will cause progressive darkening. Heat aging in the presence of water will lead to more severe adverse effects.  [c.573]

Because of the irregular structure the copolymers are amorphous and transparent. The higher the polyester component the higher the softening point, typical grades having values in the range 158-182°C compared with 148°C for unmodified polymer. On thermal aging the polyester carbonates also show a lower tendency to embrittlement than polycarbonate. This is, however, at the cost of a reduction in notched Izod impact strength (35-28 kJ/m, compared to 45 kJ/ m for unmodified polymer) and increased melt viscosity. As with the poly(co-carbonates) based on bisphenol A and bisphenol S, the polyester carbonates have a low level of notch sensitivity. The polyester carbonates are easier to process than the polyarylates.  [c.580]

Izod impact strength ftlbf in- 2-8 1.3 1.6 2.4 2.5 1.5-1.8 1.7-2.0 0.8 0.8  [c.588]

Non-self-extinguishing grades with a heat distortion temperature in the range 110-160°C and with a notched Izod impact strength of 200-500 J/m.  [c.590]

Izod impact strength 0.8 ft Ibf in notch  [c.720]

Notched Izod impact strength (3.2 mm bar) Impact strength in tension  [c.733]

Exceptionally high Izod impact strength of unreinforced grades, with one ICI grade having a quoted notched Izod figure as high as 931 J/m (approx. 18 ft Ib/in notch). Fibre reinforcement reduces this figure. It should be stressed that these figures apply to Izod test pieces, where a high level of  [c.735]

Izod impact strength (ft Ib/in) notch 1.12 3.75 6.74  [c.885]

Izod impact strength (ft Ib/in notch) 1.4-4.0 0.9-8.3  [c.891]

Trade literature can provide a wealth of information. Users should, however, bear in mind that suppliers will naturally wish to emphasise data in the best possible light. For example, if the Izod impact strength increases sharply with decrease in sample thickness, then results may be quoted for thinner section test pieces. Whilst the facts may be stated, the underlying significance may not be fully appreciated by the casual reader.  [c.892]

The study on commercial HDPE samples could not provide a correlation of the izod impact test with the field performance test, i.e., drop impact resistance on moulded products [113]. It was found that the sample of highest density and lowest izod impact strength passed the drop impact test, but other samples of lower density and higher izod impact strength could not withstand shock loading by drop impact and failed in brittle manner. This may be due to the fact that velocities and modes of loading vary widely in different impact tests. It has been reported that even the qualitative agreement between the different impact tests is poor because the test bars and moulded products often have different orientation characteristics, particularly near the surface [115].  [c.288]

Izod impact strength ( + ) (+ )  [c.289]

Elliot [38] has reported that interfacial adhesion in the NR-PP blend can be enhanced by the addition of small amounts of HOPE. Addition of HDPE does give some improvement in the notched Izod impact strength of NR-PP blend (Fig. 7). The effect of HDPE on the impact modification of NR-PP is associated with the improved crystallinity of PP, enhanced by HDPE. During the mill mixing of NR and PP, chain scission may occur to give polymeric radicals that, on reaction with  [c.643]

Izod impact strength (J m )  [c.644]

The importance of the morphological aspects of the HIPS on their Izod impact strength and gloss has been  [c.657]

Rubber particle size (/i.m) Large particles in blends (%) Rubber phase volume fraction Notched Izod impact strength ft. Ibs/in. Gloss  [c.658]

Particle diameter (urn) izod Impact Strength (J/m) Gloss (arbitrary unit) (ABS=80)  [c.659]

Izod Impact Strength (J/m) 140 76 90  [c.659]

Heterogeneous compatible blends of preformed elastomers and brittle plastics are also an important route for the development of blends of enhanced performance with respect to crack or impact resistance. Polycarbonate blends with preformed rubber particles of different sizes have been used to provide an insight into the impact properties and the fracture modes of these toughened materials. Izod impact strength of the blends having 5-7.5 wt% of rubber particles exhibits best overall product performance over a wide range temperature (RT to -40°C) [151-154].  [c.659]

Figure 2 Notched Izod impact strength of ternary PA-PP-SEBS-g-MAH blends with 0 wt%, 5 wt%, and 10 wt% SEBS-g-MAH. Source Ref. 44. Figure 2 Notched Izod impact strength of ternary PA-PP-SEBS-g-MAH blends with 0 wt%, 5 wt%, and 10 wt% SEBS-g-MAH. Source Ref. 44.
Processings Conditions. Certain variables should be monitored, measured, and recorded to aid in reproducibiUty of the desired balance of properties and appearance. The individual ABS suppHers provide data sheets and brochures specifying the range of conditions that can be used for each product. Relying on machine settings is not adequate. Identical cylinder heater settings on two machines can result in much different melt temperatures. Therefore, melt temperatures should be measured with a fast response hand pyrometer on an air shot recovered under normal screw rpm and back-pressure. Melt temperatures range from 218 to 268°C depending on the grade. Generally, the allowable melt temperature range within a grade is at least 28°C. Excessive melt temperatures cause color shift, poor gloss control, and loss of properties. Similarly, a fiU rate setting of 1 cm/s ram travel will not yield the same mold filling time on two machines of different barrel size. Fill time should be measured and adjusted to meet the requirements of getting a fliU part, and to take advantage of shear thinning without undue shear heating and gas bums. Injection pressure should be adjusted to get a fliU part free of sinks and good definition of gloss or texture. Hydrauhc pressures of less than 13 MPa (1900 psi) usually suffice for most mol ding. Excessive pressure causes flash and can result ia loss of some properties. Mold temperatures for ABS range from 27 to 66°C (60 to 82°C for high heat grades). The final properties of a molded part can be iafluenced as much by the mol ding as by the grade of ABS selected for the appHcation (121). The factors ia approximate descending order of importance are polymer orientation, heat history, free volume, and molded-ia stress. Izod impact strength can vary severalfold as a function of melt temperature and fiU rate because of orientation effects, and the response curve is ABS grade dependent (122). The effect on tensile strength is qualitatively the same, but the magnitude is ia the range of 5 to 10%. Modulus effects are minimal. Orientation distribution ia the part is very seasitive to the flow rate ia the mold therefore, fiU rate and velocity-to-pressure transfer poiat are important variables to control (123). Dart impact is also sensitive to mol ding variables, and orientation and thermal history can also be key factors (124). Heat deflection temperature can be iafluenced by packing pressure (125) because of free volume considerations (126). The orientation on the very surface of the part results from an extensionaHy stretching melt front and can have deleterious effects on electro-plate adhesion and paintabiUty. A phenomenon called the mold-surface-effect, which iavolves grooving the nonappearance half of the mold, can be employed to reduce unwanted surface orientation on the noncorresponding part surface (127—129). Other information regarding the influence of processiag coaditioas oa part quality are givea ia refereaces 130—134.  [c.206]

PiirtDesign. Eor optimum economics and production cycle time, wall thicknesses for ABS parts should be the minimum necessary to satisfy service strength requirements. The typical design range is 0.08 to 0.32 cm, although parts outside this range have been successfliUy molded. A key principle that guides design is avoiding stress concentrators such as notches and sharp edges. Changes ia wall thickness should be gradual, sharp corners should be avoided, and generous radii (25% of the wall thickness) used at wall iatersections with ribs and bosses. To avoid sinks, rib thickness should be between 50 and 75% of the nominal wall. Part-strength at weld lines can be diminished thus welds should be avoided if possible or at least placed ia aoacritical areas of the part (135). Because of polymer orieatatioa, properties such as impact strength vary from poiat to poiat oa the same part and with respect to the flow direction (121). Locations of highest Izod impact strength can be poiats of lowest dart impact strength because of the degree and direction of orientation. ABS suppHers can provide assistance with design of parts upon iaquiry and through design manuals (136). There are a number of special considerations when designing parts for metal plating to optimize the plating process, plate deposition uniformity, and final part quaHty (137). ABS parts can be also designed for soHd—soHd or soHd—foam co-iajection mol ding (138) and for gas-assisted-iajection mol ding (139).  [c.206]

Izod impact strength, J /m of notch ASTM D256 21.35-53.38  [c.441]

Figure 7 Effect of addition of HOPE on Izod impact strength of NR-PP blend. (O) 20 80 NR-PP homopolymer, (V) 20 67 13 NR-PP-homopolymer-HDPE, ( ) 15 85 NR-PP copolymer grade, and (x) 15 75 10 NR-PP-copo-lymer-HDPE. Figure 7 Effect of addition of HOPE on Izod impact strength of NR-PP blend. (O) 20 80 NR-PP homopolymer, (V) 20 67 13 NR-PP-homopolymer-HDPE, ( ) 15 85 NR-PP copolymer grade, and (x) 15 75 10 NR-PP-copo-lymer-HDPE.
Figure 6 Dependence of Izod impact strength on the DMAE concentration in 80 20 PS-bromo butyl rubber blends. Source Ref. 53. Figure 6 Dependence of Izod impact strength on the DMAE concentration in 80 20 PS-bromo butyl rubber blends. Source Ref. 53.
PMMA-b-PBA shows improved izod impact strength compared to PMMA homopolymer (41). Polyisobutylene (PIB) or its hydrogenated one (PIB-H) also acts as an impact modifier [31]. PSt-b-PIB, PSt-b-PIB-H, and PMMA-b-PIB-H derived from MAI have high- and wide-range molecuiar weight and show high flexibiiity and flow property [42]. The improved flexibiiity of PMMA-b-PEG synthesized as an elastomer, was confirmed by dynamic viscoelastic measurement [43].  [c.761]


See pages that mention the term Izod impact strength : [c.57]    [c.191]    [c.360]    [c.428]    [c.266]    [c.267]    [c.405]    [c.532]    [c.218]    [c.859]    [c.640]    [c.644]    [c.671]   
Plastics materials (1999) -- [ c.454 , c.573 , c.895 ]