Wood flour: A new filler for the rubber processing industry. I. Cure characteristics and mechanical properties of wood flour‐filled NBR and NBR/PVC compounds

Abstract

ABSTRACT:In this study, conifer wood flour was evaluated as a filler to NBR or NBR/PVC compounds studying it influence on their cure characteristics and mechanical properties. It was shown that the filling by wood flour offers a possibility to obtain high modulus high elastic or less elastic or rigid wood like vulcanizates by varying of both the filling level and NBR/PVC mass ratio.It was established that in contrary to the mineral fillers usually causing significant delay of the vulcanization process, the wood flour shows a tendency to reduce the optimum cure time, 90 . Modulus M 100 and Shore hardness of the wood flour-filled vulcanizates of NBR or NBR/PVC compounds in which NBR is predominant, increase in a compliance with the increase of M max and DM when the filling level increases. The dependence is other when NBR and PVC are in equal amounts or PVC predominates. As a most probable explanation of the effect of the wood flour on the cure characteristics is accepted, the influence of the wood flour polar groups as well as of the presenting as wood flour humidity water molecules, the specific mechanical properties of the wood flourfilled NBR or NBR/PVC compounds could be connected (to some extend) with a specific interface interaction between the wood flour particles and the polymer matrix.

Effect of a coupling agent on the properties of hemp‐hurd‐powder‐filled styrene–butadiene rubber

“…When the loading of HP increased from 0 to 60 phr, E B reached its maximum value. This was entirely different from the previous report,24 in which the E B of composites showed a drastic decrease with the addition of short fibers.…”

Wood flour: A new filler for the rubber processing industry. III. Cure characteristics and mechanical properties of nitrile butadiene rubber compounds filled by wood flour in the presence of phenol‐formaldehyde resin

“…No clearly expressed regularity is observed, but it is evident that all compounds containing PFAR (mixtures 2–16; 7′‐12′ and 7′‐12″ in Table III) filled by nonmodified (mixtures 2–16; 7′‐12′ in Table III) or corona‐treated (mixtures 7′‐12″ in Table III) wood flour have increased thermal‐oxidative stability compared to the control mixture (mixture 1 in Table III) that does not contain nor PFAR or wood flour. Such a result is not surprising because 1) the PFAR usually increases5, 6 the aging resistance of the rubber and 2) the wood flour does not influence significantly the aging resistance of the NBR vulcanisates1.…”

“…We studied earlier the effect of nonmodified1 as well as of corona‐treated conifer wood flour11 as a filler to NBR compounds in the absence of any interface interactions modifier. This study was aimed to evaluate PFAR as an interface interactions modifier, therefore, our experiments were carried out in three sets:…”

“…In a former study1 we found that the wood flour acts as nonreinforcing filler in nitrile butadiene rubber (NBR) compounds. Scanty information about wood flour modification directed to its application as an active filler in polymer composites or rubber compounds could be found in the technical literature.…”

Wood flour: A new filler for the rubber processing industry. II. Cure characteristics and mechanical properties of NBR compounds filled with corona‐treated wood flour

“…In a previous investigation1 we studied the effect of nonmodified conifer wood flour in nitrile butadiene rubber (NBR) and NBR/poly(vinyl chloride) (PVC) compounds. We found that filling compounds with wood flour offers the possibility of obtaining high modulus, highly elastic or less elastic, or rigid woodlike vulcanizates by varying both the filling level and the NBR/PVC mass ratio.…”