Lifetime of Plastics and Plastic-based Composites Examples

INTRODUCTION. LIFETIME OF PLASTICS AND PLASTIC-BASED COMPOSITES EXAMPLES 

All plastics, as well as all organic materials, retain their functional properties during only a certain period of time. There are multiple events that shorten the lifetime of plastics—some of them are accidental, such as mechanical failure as a result of reaching an ultimate load, that is, a break load for a given profile, or a critical impact resistance, or a case of fire, and some of them are cumulative, spreading over a long time period, such as wear and tear, or thermo- and photooxidation. 

In this chapter we will focus on thermo- and photooxidation and their combined effect on plastic-based hber/mineral composite materials. 

Thermooxidation of plastics is a relatively well-developed area of polymer chemistry. It is a dramatically underdeveloped area of composite building materials. 

The resistance of commercial polymer grades to thermooxidation is commonly indicated by their UL temperature index (Table 15.1). It shows at which continuous temperature the polymer will serve for 100,000 h, that is, 11.4 years. Will serve in this context means until its impact strength, or strain at break, or other chosen mechanical property is reduced by 50%. 

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