Reference

Synthesis and use of phenolic resol resins in the manufacture of high-speed abrasive disks

Synthesis and use of phenolic resol resins in the manufacture of high-speed abrasive disks. Deyanov, D.; Nenkova, T.; Novakov, P. (Bulg.). Khim. Ind. (Sofia), 48(9), 404-6 (Bulgarian) 1976. CODEN: KINSAF. DOCUMENT TYPE: Journal CA Section: 36 (Plastics Manufacture and Processing) The optimum conditions are detd. for prepn. of FL 2 (phenol-formaldehyde polymer)(I) [9003-35-4] with improved mech. properties used for manuf. of abrasive discs. The resol type I was prepd. in a 2-stage process, at a PhOH-HCHO ratio 1:1.3, in the presence of NH3 [7664-41-7] and Ba(OH)2 [17194-00-2] as catalysts. The rupture strength of I was 18,000 rpm and the wear of the abrasive disc was 0.82 g/min.

Preparation of solution polymers

Preparation of solution polymers. Hargis, Ivan G.; Livigni, Russell A.; Aggarwal, Sundar L. (General Tire and Rubber Co., USA). U.S. US 3992561 16 Nov 1976, 17 pp. (English). (United States of America). CODEN: USXXAM. CLASS: IC: C08F004-46. NCL: 526181000. APPLICATION: US 75-593579 7 Jul 1975. DOCUMENT TYPE: Patent CA Section: 38 (Elastomers, Including Natural Rubber) Butadiene is soln. homopolymd. or copolymd. with isoprene or styrene in the presence of a catalyst comprising a Ba di-tert-alkoxide-Ba hydroxide complex and an organolithium compd. to give rubbers having .apprx.12% vinyl and 70-81% trans-1,4 structure, a broad mol. wt. distribution, and good tack and green-strength. Thus, a mixt. of 5.18g Ba metal, 500 mL MeNH2, and 7.55 mequiv H2O was cooled to -70.degree. with vigorous stirring, and 69.4 mequiv tert-butanol in C6H6 (3 M) was added to give a gray suspension which was flash distd. to give 10.31 g gray-white powder contg. 91 mol% Ba tert-butoxide [24363-36-8] and 9 mol% Ba(OH)2 [17194-00-2]. Butadiene (20g) was polymd. in toluene in the presence of 0.66 mmol BuLi [109-72-8] and 0.33 mmol Ba product to 95% conversion to give a polymer having 78% trans and 8% vinyl structure and 0.45 dL/g viscosity. Press molding sheets 5 min at 100.degree. and 13,608 kg ram force gave a rubber having Mooney viscosity (ML-4, 100.degree.) 54, yield strength 128 psi, tensile strength 366 psi, and elongation at break 1433.degree., compared with 54, 22, 10, and 338, resp., for a com. soln.-polymd. butadiene rubber.