Dicumyl peroxide dcp

Composition of the rubber compounds studied is presented in Table 1.
The rubber compounds studied were prepared in a Brabender Plasticorder laboratory micromixer (Germany), and then plate-calibrated to 2 mm thickness. The following mixing conditions were applied: rotational speed of 30 rpm; time of 7 min, room temperature. First, the rubber was plasticized for 3 min, then the appropriate amount of dicumyl peroxide (DCP, 98% of purity, Sigma-Aldrich Ltd., Poznan, Poland) was added and mixed together for another 2 min, and then the CPO modifier was added to the micromixer chamber. The whole content was then mixed for another 2 min. The samples were crosslinked in steel form under pressure, at 160 °C and during the optimum time of curing—t90, determined rheometrically, according to ISO 3417.

Poly(L-lactic acid) (PLLA) matrix under the trade name of Luminy L130 was supplied by Total Corbion PLA (Gorinchem, The Netherlands). It has an approximate molar mass of 170,000 g/mol, a glass transition temperature (T_g) of 60 °C, a melting point of 175 °C, and contains more than 99% of L-lactide. Particulate spent coffee ground filler (SCG) Kimbo 100% Arabica (De’Longhi S.p.A., Treviso, Italy) was ground to an average particle size lower than 20 µm. In addition to that, 95% itaconic anhydride (IA) (Sigma-Aldrich, Darmstadt, Germany) with an approximate molar mass of 112 g/mol in the form of a powder as a compatibilizer agent and 98% dicumyl peroxide (DCP) (Sigma-Aldrich, Darmstadt, Germany) with an approximate molar mass of 270 g/mol as an initiator was used. Dehydrated acetone (ACROS Organics, Geel, Belgium) was applied to dissolve DCP and IA. A liquid form of ATBC, Citroflex A-4 delivered by Vertellus Holding LLC (Indianapolis, IN, USA), was used as a plasticizer.

Natural rubber (NR) purchased from InfoChems (RSS#3, Goyang City, Gyeonggi-do, Korea) was adopted as an elastomeric matrix. Multi-walled carbon nanotubes (MWNT, JEIO, Incheon, Korea) were used as conductive fillers. This MWNT had a diameter of 5–7 nm, a bundle length of 50–150 μm, and purity of >96.5 wt.%. Dicumyl peroxide (DCP), used as a crosslinking agent, was purchased from Sigma Aldrich (St. Louis, MO, USA), and chloroform, used as a solvent for NR and MWNT, was purchased from DAEJUNG Chemicals (Siheung, Korea).

Polymer

ENGAGE™ polyolefin elastomer: ethylene-octene rubber (EOR) containing 25 wt.% co-monomer octene was obtained from DOW Chemical Company (Midland, Michigan, USA). The Mooney viscosity was (ML (1 + 4) at 121 °C: 35).

Crosslinking agent

Rubber mixtures were vulcanized with dicumyl peroxide DCP (purity: 98%) produced by Sigma Aldrich (St. Luis, Missouri, USA).

Fillers

Cereal (wheat, oat, rye, barley, and triticale) straw was collected from local farms. Dried straw was crushed using a blixer (Blixer 4, Robot Coupe, Vincennes, France) with a grinding time of 20 min at a speed of 3000 rpm. Then sieve analysis was performed by using: vibratory shaker, set of sieves with 2.0; 1.0; 0.5; 0.25 mm nominal mesh size. In following studies, the fractions: 1.0–0.5; 0.5–0.25; 0.25 mm were used.
The compositions of ethylene-octene copolymer mixtures intended for vulcanization (Table 1) and injection process (Table 1) are presented in Table 1.

A maleated EPM (EPM-g-MA, Keltan DE5005, 49 wt % ethylene, 2.1 wt % MA, M_n = 50 kg/mol, polydispersity index = 2.0) were kindly provided by ARLANXEO Performance Elastomers. Furfurylamine (FFA, Sigma-Aldrich, St. Louis, MO, USA, ≥99%) was freshly distillated. Multi-walled carbon nanotubes (CNT, Sigma-Aldrich, diameter × L 6–9 nm × 5 µm, >95% (carbon)) were used as additive and cross-linking agent. 1,1′-methylenedi-4,1-phenylene)bismaleimide (BM, Sigma-Aldrich, ≥97%) and dicumyl peroxide (DCP, Sigma-Aldrich, 98%) were used as reversible and irreversible cross-linking agents, respectively. 3-azido-1-propanamine (90%), octadecyl-1-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (anti-oxidant, 99%), 1-methyl-2-pyrrolidinone (NMP, 99.5%), tetrahydrofuran (THF, >99.9%), decahydro naphthalene (decalin, mixture of cis + trans, >98%) and acetone (>99.5%) were all bought from Sigma-Aldrich and used as received.

Poly(3-hydroxybutyrate) was supplied by Biomer^® (Schwalbach, Germany) in pellet form (P309). Purified alpha-cellulose fiber grade with an alpha-cellulose content >99.5% (TC90) was purchased from CreaFill Fibers Corp. (Chestertown, MD, USA). Rice husk (RH) by-product from the rice production process was kindly provided by Herba Ingredients (Valencia, Spain). The four reactive agents used (dicumyl peroxide (DCP), hexamethylene diisocyanate (HMDI), resorcinol diglycidyl ether (RDGE), and triglycidyl isocyanurate (TGIC)) were purchased from Sigma Aldrich (Madrid, Spain). Sodium hydroxide (NaOH, 98%), hydrogen peroxide (H₂O₂, 30%), glacial acetic acid (CH₃COOH, 99%), and sulfuric acid (H₂SO₄, 98%) were purchased from Sigma Aldrich (Madrid, Spain).

Commercial cellulase enzyme (NewCell Conc L) was purchased from NewEnzymes, Pedrouços, Portugal. Cellulase and 2-benzisothiazolin-3(2H)-one (>1%) made up the enzyme preparation. α-Amylase from Bacillus sp., type II-A, lyophilised powder (≥1500 units/mg protein), glucoamylase from Aspergillus niger, powder (~120 U/mg), poly (methyl methacrylate) (Mw: 50,000 Da), Lipase B from Candida antarctica immobilised on Immobead 150, recombinant from Aspergillus oryzae with enzyme activity ≥1800 U/g, and dicumyl peroxide (DCP) were provided from Sigma-Aldrich, Darmstadt, Germany. All chemicals for the microbial cultures were obtained from Pol-Aura, Olsztyn, Poland. The other chemicals and solvents were purchased from Alchem, Wrocław, Poland.