Adhesion silane treatment effect

IFSS are much more striking, emphasizing the fact that the effectiveness of silane treatment is more important in retaining fiber-matrix adhesion under conditions of exposure to moisture. 

George et al. (1996) treated pineapple leaf fiber with polymethylene-polyphe-nyl-isocyanate (C15H10N2O2) solution at 50°C for 30 min to improve the fiber-matrix interfacial adhesion. Comparing silane and isocyanate-treated wood fiber-PS composites, it was reported that isocyanate treatment was more effective than silane treatment in enhancing the mechanical properties of cellulose fiber-PS composites (Maldas et al. 1989). 

Effect of fiber treatments Alkali treatment on OPFs significantly improved its interfacial shear strength in polyester matrix [14]. Alkali treatment washed out the outer skin, better exposing fiber to the polyester matrix, leading to proper interaction between their surfaces. In addition, the fine holes created on alkali treatment allowed the polyester to penetrate into the fiber bundles in a better way. Acetylation treatment to the fibers improved impact strength of OPF-polyester composites due to improved fiber wettability and resulting fewer void spaces [71]. The tensile stress of OPF-polyester composites increased slightly upon both acetylation and silane treatments on fibers and decreased upon titanate treatment [14]. The flexural modulus of OPF-PP composites also increased considerably upon acetylation treatment on fibers. Similarly the abrasion resistance of OPF-polyester composites was enhanced upon alkali treatment to fibers [13]. Treated fibers enhanced the adhesion resistance of polyester resin by 75-85%, while untreated fibers enhanced the abrasion resistance only by 50-60%. 

The beneficial effects of surface treatments of filler particles, including silane treatments, are generally attributed to improved adhesion of the polymer to the filler surface. However, it should be realised that in many cases the changes in the degree of agglomeration brought about by the surface treatments are equally, or more, important [83]. 

Increased adhesion, as indicated by peel tests, consistently improves certain mechanical properties in all rubbers, has little effect on some properties, and varies with the type of rubber in other properties. Each trend in properties is accentuated by increasing the level of silane treatment from 0.5% to 1.0%. 

It was found that alkali and silane treatments also increased the tensile and flexural strength of PLA/ramie composites, exhibiting that alkali treatment (5 wt%, 3h) is more effective than silane treatment (APS and GPS, 24h) [145]. Oxygen plasma treatment of jute fibers improved the tensile and flexural properties of jute/HDPE composites, showing that radio frequency (RE) plasma treatment was more effective than low frequency (LE) plasma treatment up to 60 W [139]. Oligomeric siloxane treatment after alkali treatment of jute fibers resulted in an additional increase in both tensile and flexural strengths of JEP and JUP composites, compared with either alkali or silane treatment alone, resulting from the increase of fiber-matrix adhesion by surface treatment, as mentioned earlier [53]. 

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