Thermoforming of polymer from monomers in wood porous structure and characterisation for wood–polymer composite

Abstract

Inspired by the porous structure of wood, a novel bio‐based composite, wood–polymer composite, was fabricated by thermoforming polymer from monomers [methyl methacrylate (MMA) and styrene (St)] in situ in the wood’s porous structure through a catalyst thermal treatment. SEM observation indicated that polymer was generated in situ and satisfactorily filled up wood pores without noticeable lacunae. FTIR analysis suggested that MMA and St copolymerised in the wood pores, and the resultant polymer was grafted onto the wood matrix through the reaction of ester group of MMA and hydroxyl group on wood components, achieving a chemical complex, which is in agreement with SEM observations. DMA analysis showed that the graft of copolymer of MMA and St onto wood improved the interface interaction between wood matrix and polymer, which rendered both the glass transition temperature and storage modulus at normal temperature of wood–P(MMA‐co‐St) composite evidently increased. The mechanical properties of wood–P(MMA‐co‐St) composite including modulus of rupture, compressive strength, wearability and hardness were improved by 53, 42, 74 and 198% compared with those of untreated wood respectively. And there were liner positive correlation between compression strength and content of polymer loading, as well as hardness and content of polymer loading respectively. Such composite combing both advantages of wood and polymer, as well as making full use of renewable resource, may be capable of becoming a promising material which can be widely used in fields of construction, traffic, furniture and so forth.

Keywords:

• Wood–polymer composite
• Porous structure
• Thermoforming
• Monomer

The authors would like to acknowledge the financial supports of the Breeding Plan of Excellent Doctoral Dissertation of Northeast Forestry University (OPTP10‐NEFU) and the Programme of Introducing Talents of Discipline to Universities (‘111 Programme’).