Interfacial adhesion of pine wood filled PP compounds via effects of volatile extractives

Abstract

Effects of volatile extractives in pine wood (PW) particles are investigated upon interfacial adhesion, nucleation behavior and mechanical properties in polypropylene (PP) matrix. Various concentrations of the PW are filled in PP, i.e. PP/PW [90/10 (PP10), 75/25 (PP25) and 50/50 wt% (PP50)]. As the concentration of the PW particles is increased, the crystalline peak temperature is increased, the melting peak temperature is decreased, the elongation strain is decreased and the amount of volatile extractives in the PW is increased. Few spherulites are locally developed at the interface between the PW and the PP. The PW acts as a nucleating agent; however, it does not help reinforcing of the PP/PW compounds.The volatile extractives in the PW particles seems to evaporate-and migrate-out during the processing and then coats the pine wood surface, trapped in the compound, and migrats out to the wall surface. This results in a poor interfacial adhesion between the PW and the PP.

Modification of nano-kenaf surface with maleic anhydride grafted polypropylene upon improved mechanical properties of polypropylene composite

“…[8,27] Natural fiber consists of cellulose, lignins and contain extractable chemicals including fatty acids, water, sugars, starches, oils, resins, waxes, pectins, tannins, amino acids, proteins, etc. [28][29][30][31][32] The adhesion between natural fiber and matrix polymer is hindered by lignins and volatile extractives. These lead to poor adhesion between fiber and polymer matrix.…”

“…[11,33] It has been confirmed by researchers that volatile extractives are present in natural fiber [29,34] and they are responsible for decrease of mechanical property of the compound. [11,31,[35][36][37] Yosomiya argued that poor adhesion of a material is due to presence of low surface tension material such as impurities or adsorbed water layers. [38] This leads to interfacial de-wetting between fiber surface and polymer matrix.…”

Effects of Alkali Treated Nano-kenaf Fiber in Polypropylene Composite upon Mechanical Property Changes

“…range from 5 to 20 wt%. [39][40][41][42][43][44] They hinder the adhesion between natural wood particle and matrix polymer. This leads to poor adhesion between fiber and polymer matrix.…”

“…45,46 It has been confirmed by studies that volatile extractives are present in natural fiber 40,47,48 and they are responsible for decrease of mechanical property of the compound. 27,42,45,47,49 Yosomiya argued that poor adhesion of a material is due to presence of low surface tension material such as impurities or adsorbed water layers. 50 This leads to interfacial de-wetting between fiber surface and polymer matrix.…”

Nano-Kenaf Cellulose Effects on Improved Mechanical Properties of Polypropylene Composite

“…These lead to poor adhesion between fiber and polymer matrix. 16,[20][21][22] It has been confirmed by researchers that volatile extractives are present in natural fiber 18,23,24 and they are responsible for decrease of mechanical property of the compound. [20][21][22]25,26 Volatile extractives consist of low molecular weight polymers and act as a plasticizer (e.g.…”