Maleated polypropylene film and wood fiber handsheet laminates

Abstract

The grafting effect of maleic anhydride (MA) as an interfacial bonding agent and its influence on the tensile strength properties of thermomechanical pulp handsheet-isotactic polypropylene (iPP) film laminates was studied. For the MA treated with benzoyl peroxide (BPO) as an initiator, tensile strength properties increased 76% with PP film over untreated laminates. The optimal strength properties were obtained with a MA and BPO ratio of 2:1. A strong correlation was observed between the number of fibers in the web and tensile strength properties for both handsheet drying conditions. The R 2 values were 0.95 for air-dry conditions and 0.94 from oven-dry conditions. Scanning electron microscopy images also showed the effectiveness of MA loading on the surface of thermomechanical pulp fibers due to increased fiber failure, which occurred without fiber being pulled out from the PP matrixes. Crystallinity and heat flow were determined using differential scanning calorimetry (DSC) and increased as expected as the ratio of MA and BPO increased from 0:0 to 2:1. These results were also in accordance with the morphological observations at the fracture surface, Fourier transform infrared spectra, and thermal analysis.

Highly compatible wood thermoplastic composites from lignocellulosic material modified in ionic liquids: Preparation and thermal properties

“…Unfortunately, the large polarity difference between lignocellulosic materials and nonpolar thermoplastics, e.g., poly(ethylene), poly (propylene), poly(styrene), etc., have prevented lignocellulosic materials from performing effectively as reinforcing agents, or even fillers within traditional thermoplastics. In most cases, techniques for increasing phase compatibility, such as coupling agents, have been used to augment interfacial bonding of the different phases, aimed at improving the processability and performance of WPCs 4–6. Among these technologies, due to recent advances in the potential for wood processing in ionic liquids such as 3‐allyl‐1‐methylimidazolium chloride ([amim]Cl), chemical modification of the lignocellulosic material should be considered as an effective approach for investigating and tailoring the properties of bio‐plastics, by physically blending modified natural with synthetic polymers 11, 12…”

“…Such materials should be, almost invariably, biologically‐derived with the annually renewable agricultural and biomass feed stocks occupying a prominent position 1–3. Wood is among the most abundant lignocellulosic resources on the planet and has been considered to be a pivotal component for the production of bio‐composites, otherwise referred to as “wood‐thermoplastic composites” or simply “wood plastic composites” (WPCs) 4–6. Lignocellulosic materials, including wood fibers, wood flour, etc., have been used as fillers for thermoplastics 7–10.…”

Characteristics of regenerated nanocellulosic fibers from cellulose dissolution in aqueous solutions for wood fiber/polypropylene composites

“…This may result in relatively strong strength properties of the composites, which can obtain the mechanical properties of the control fiber reinforcement. 22,23 This also implies that the nanofibers were incorporated into the PP matrix and…”

Alkyl ketene dimer modification of thermomechanical pulp promotes processability with polypropylene

“…31 Urea-and phenol-formaldehyde increases the tensile strength of TMP hand-sheets and PP films, 32 similar to maleic anhydrate and benzoyl peroxide, and is taken as an indication of improved compatibility between TMP and PP. 33 TMP modified with benzoyl or lauroyl shows good melt and process properties when used as a composite. 34 Alkyl ketene dimer (AKD) is one of the most commonly used sizing agents in papermaking, 35,36 used to control hydrophobicity/hydrophilicity of fibers in the pulp and paper industry.…”