Impact transparent

Not all graphs are created equal. Just as with statistical methods, mindful attention to the objectives (or messages) the graph intends to convey is a key factor in producing impactful, transparent graphs. Utilization of the basics of graphics design principles is important as well. ... 

Polyallyl diglycol carbonate n. A high-impact, transparent thermoplastic with excellent abrasion resistance, made from Pittsburg Plate Glass Industries CR-39 monomer (and hence sometimes called CR-39). It is widely used in eyeglasses. 

Its key properties are its excellent transparency, rigidity, and chemical resistance, plus its resistance to impact and to high temperatures. It withstands repeated autoclaving, even at 150°C. 

Plastic Sheet. Poly(methyl methacrylate) plastic sheet is manufactured in a wide variety of types, including cleat and colored transparent, cleat and colored translucent, and colored semiopaque. Various surface textures ate also produced. Additionally, grades with improved weatherabiUty (added uv absorbers), mat resistance, crazing resistance, impact resistance, and flame resistance ate available. Selected physical properties of poly(methyl methacrylate) sheet ate Hsted in Table 12 (102). 

Initially, DADC polymers were used in military aircraft for windows of fuel and deicer-fluid gauges and in glass-fiber laminates for wing reinforcements of B-17 bombers. Usage in impact-resistant, lightweight eyewear lenses has grown rapidly and is now the principal appHcation. Other uses include safety shields, filters for photographic and electronic equipment, transparent enclosures, equipment for office, laboratory, and hospital use, and for detection of nuclear radiation. 

It would be incomplete for any discussion of soap crystal phase properties to ignore the colloidal aspects of soap and its impact. At room temperature, the soap—water phase diagram suggests that the soap crystals should be surrounded by an isotropic Hquid phase. The colloidal properties are defined by the size, geometry, and interconnectiviness of the soap crystals. Correlations between the coUoid stmcture of the soap bar and the performance of the product are somewhat quaUtative, as there is tittle hard data presented in the literature. However, it might be anticipated that smaller crystals would lead to a softer product. Furthermore, these smaller crystals might also be expected to dissolve more readily, leading to more lather. Translucent and transparent products rely on the formation of extremely small crystals to impart optical clarity. 

Polycarbonates. Polycarbonates (qv) are pardy crystalline thermoplastics with some disorder in the crystalline part and considerable order in the amorphous part. This disorder conveys high impact strength which, combined with its good transparency and outdoor exposure resistance, makes polycarbonates usefiil for vandal-resistant glazing and outdoor lighting. It is easily processed by extmsion and injection mol ding. Various uv and dame-retardant agents are often added. 

Research. A significant impact on research at high pressure has come about with the use of gem quaHty diamonds as Bridgman-type anvils in a smaU compact high pressure device (40—42). With this type of apparatus, pressures greater than those at the center of the earth (360 GPa = 3.6 Mbars) have been reached, and phase transformations of many materials have been studied. Because of the x-ray transparency of diamond, it is possible to determine the stmcture of the phases under pressure. Because of the strenuous environment, crystals selected for this appHcation have to be of very high quaHty. 

Figure 4.25. Experimental configuration for optical pyrometry of shock temperatures induced in transparent minerals. Upon impact of projectile with driver plate, a shock wave is driven into the driver plate and then into the sample. Optical radiation from the sample is detected via six lens/interference filter channels and an array of six photodiodes. Signals from photodiode circuits are recorded on oscilloscopes operating in single sweep model. (After Ahrens et al. (1982).)...

This daia indicates that the random copolymer has greater transparency but inferior low temperature impact strength. 

There are a number of occasions where a transparent plastics material which can be used at temperatures of up to 150°C is required and in spite of its relatively high cost, low impact strength and poor aging properties poly-(4-methylpent-1 -ene) is often the answer. Like poly(vinyl chloride) and polypropylene, P4MP1 is useless without stabilisation and as with the other two materials it may be expected that continuous improvement in stabilising antioxidant systems can be expected. 

The commercial polymers are mechanically similar to PTFE but with a somewhat greater impact strength. They also have the same excellent electrical insulation properties and chemical inertness. Weathering tests in Florida showed no change in properties after four years. The material also shows exceptional non-adhesiveness. The coefficient of friction of the resin is low but somewhat higher than that of PTFE. Films up to 0.010 in thick show good transparency. 

Because of such desirable characteristics as low cost, good mouldability, excellent colour range, transparency, rigidity and low water absorption, polystyrene became rapidly developed. For many purposes, however, it was considered to be unacceptably brittle and this led to the development of the rubber-modified high-impact polystyrene (HIPS) and to the complex ABS, AMBS and... 

Tough transparent sheet may be produced by blending standard polystyrene with block copolymer in an extruder in the ratios 80 20 to 20 80, depending on the application of the products subsequently thermoformed from the sheet. For example, sheet for thermoforming an egg tray will not require the same level of impact strength as that required for jam jars. 

Blending of ABS with an acrylic material such as poly(methyl methacrylate) can in some cases allow a matching of the refractive indices of the rubbery and glassy phases and providing that there is a low level of contaminating material such as soap and an absence of insoluble additives a reasonable transparent ABS-type polymer may be obtained. More sophisticated are the complex terpolymers and blends of the MBS type considered below. Seldom used on their own, they are primarily of use as impact modifiers for unplasticised PVC. 

As mentioned earlier, unmodified polystyrene first found application where rigidity and low cost were important prerequisites. Other useful properties were the transparency and high refractive index, freedom from taste, odour and toxicity, good electrical insulation characteristics, low water absorption and comparatively easy processability. Carefully designed and well-made articles from polystyrene were often found to be perfectly suitable for the end-use intended. On the other hand the extensive use of the polymers in badly designed and badly made products which broke only too easily caused a reaction away from the homopolymer. This resulted, first of all, in the development of the high-impact polystyrene and today this is more important than the unmodified polymer (60% of Western European market). 

Copolymers of vinylidene chloride with 5-50% acrylonitrile were investigated by IG Farben during World War II and found to be promising for cast films. Early patents by ICC and Dow indicated that the copolymers were rigid, transparent and with a high impact strength. 

Polycarbonates with superior notched impact strength, made by reacting bisphenol A, bis-phenol S and phosgene, were introduced in 1980 (Merlon T). These copolymers have a better impact strength at low temperatures than conventional polycarbonate, with little or no sacrifice in transparency. These co-carbonate polymers are also less notch sensitive and, unlike for the standard bis-phenol A polymer, the notched impact strength is almost independent of specimen thickness. Impact resistance increases with increase in the bis-phenol S component in the polymer feed. Whilst tensile and flexural properties are similar to those of the bis-phenol A polycarbonate, the polyco-carbonates have a slightly lower deflection temperature under load of about 126°C at 1.81 MPa loading. 

Methylpentene polymer, a light plastic, has a crystalline melting point of 464 retention up to 392° F, transparency of 92%, and electrical properties similar to fluoroethylene. Its impact strength is greater than polystyrene and polymethyl methacr resistant to alkalies, weak acids, and non-chlorinated solvents. It may be injection m< implements for food packaging and preparation, medical care, and non-stick coating ... 

A use is for internally illuminated signs in which any color can be introduced. Its dii sional stability recommends it for many optical uses. Acrylics are modified by copoly-mf ition to improve impact strength at the loss their extreme transparency.. An example is aci -modified polyvinyl chloride sheet, which is tougher than aciylonitrile-butadiene-styrene and polycarbonate and is suitable for corrosion-resistant pans, aircraft parts and materia idling equipment. 

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