**3.2 Scanning electron microscopy**

The scanning electron microscopy depicts the morphology of virgin and recycled thermoplastics at fracture surfaces when stressed and characterized the ductile, toughness, stiffness, and brittle nature of HDPE, LDPE, PCV, PET, and PP without modification [32], but improvement in compatibility using EPDM compatibilizer has been reported [2, 70]. The improvement in rheological morphology does not indicate an improvement in compatibility as well as mechanical properties [71]. Modification of recycled HDPE with treated natural fiber using NaOH, SLS, acetic anhydride, CaCO3 filler, and zeolites as well as synthetic fibers is characterized with improvement in polymer dispersion, even distribution of fibers, interfacial adhesion, fiber tearing, micro-crack formation, modifier content and size, nature of the modifier, and reduction in void formation [20, 43, 72–75]. This indicated the enhanced compatibility which corroborates the improvement in physical, mechanical, and thermal properties of the modified recycled thermoplastics and dictates its applications.

**65**

*Thermoplastic Recycling: Properties, Modifications, and Applications*

mixed wastes have been reported by Lageraaen and Kalb [76].

from economic, environmental, and health issues [76].

components [29], and building floor applications [52].

The application of the HDPE composites is a function of the favorable properties coupled with cost implication of the production, and it may be affected by additional modified agents such as fiber or filler, NaOH, acetic anhydride, zeolite, and sodium lauryl sulfate. The use of recycled HDPE composites has been reported for many applications such as packaging (food storage containers and bottles for milk jugs) [13, 28, 38], banners, swimming pool installation, corrosion protection for steel pipelines, folding chairs and tables, electrical and plumbing boxes, plastic surgery (skeletal and facial reconstruction) [27], modified asphalt for pavement and road construction [29, 59, 75], housewares, industrial wrapping and gas pipes [30], and storage sheds, enhancing the economic, health, and social values as well as minimizing environmental issues that might be posed by HDPE disposal [38]. Applications of recycled HDPE in the encapsulation of radioactive, hazardous, and

Incorporation of recycled LDPE at concentrations ranging from 2 to 5% by mass of bitumen possesses consistent desirable properties for bitumen asphalt applications [51, 69]. Utilization of LDPE for production of liquid milk packaging [16], bread packaging and sandwich bags, housewares, toys, buckets, wire and cable jacketing, and carpet [13, 38, 68] and use of recycled thermoplastics for encapsulation of hazardous, radioactive, and mixed waste disposal save the environment

Polyvinyl chloride waste has been used in plumbing pipes and fittings, but its utilization as a binder in bitumen applications has been found unsuccessful due to high melting points which hindered the mixing as a result of poor compatibility [51]. PVC sheets have been reported to be employed for making food trays, cling film and blister packages [13], household appliances, packaging, construction, medicine such as human rehabilitation, electronics, automotive and aerospace

Recycled PET could be used for making waterproof [13] water and soft drink bottles, thermally stabilized films (e.g., capacitors, graphics, film base and recording tapes, etc.), electrical components, and textile products [58] if properly modified. The use of recycled waste PET as a modifier in bitumen road and pavement construction is hindered by mixing ratio and processing conditions due to high melting point [51]. It is widely used in making automobile part, electronics, food packaging, house ware, lighting product, power tools, sports tools, x-ray sheets, and

Recycled polypropylene can be used for packaging articles, automobile bumper, foams, bottle tops, carpets, and household components [13] and in making straws

*DOI: http://dx.doi.org/10.5772/intechopen.81614*

**4.1 Applications of recycled HDPE**

**4.2 Applications of recycled LDPE**

**4.3 Applications of recycled PVC**

**4.4 Applications of recycled PET**

photographic applications [55, 59].

**4.5 Applications of recycled PP**

**4. Application of recycled thermoplastics**
