What was the adjusted cash flow conversion rate for the company in the second quarter
nic growth of 21%, a favorable palladium impact of 4% and an 8% benefit from FX translation. Organic growth in chemistry revenue for Electronics was 9% in the quarter, underpinned by the strong growth in the smartphone market as well as sustained growth in the high-performance PCB and semiconductor-related businesses.
As mentioned in May, this growth has been anticipated, and we are pleased to see it unfold. That said, please keep in mind that 2020 saw some shifts in typical seasonality. Work from home created stronger demand for laptops in the third quarter and a well-known OEM shifted its product launch patent into the fourth quarter. As we lap this quarter, the base effect may cause mathematically lower growth rates compared to what we reported in the first half of 2021.
Electronic equipment sales enjoyed another outstanding quarter with organic revenue up 115%. The demand stems from the sources we have outlined previously, the full transition to 5G for the smartphone manufacturers with a high demand for computing. Our next-generation machines are in high demand as OEMs and PCB manufacturers seek to meet consumer demand. Electronics generated $85 million of adjusted EBITDA in the quarter, a $23 million or 36% improvement over the prior year period, primarily driven by the strong organic volume growth and our lean cost structure.
Margin was 34.3% in the quarter, up 20 basis points, which is a reflection of the robust organic volume growth, partially offset by product mix effects from high equipment sales and the palladium pass-through. Moving to Slide 6 now. GMF total revenue grew 71% to $129 million in the second quarter, comprised of organic growth of 59%, a 1% positive impact from palladium and an 11% tailwind from FX. From a mix perspective, chemistry revenues grew organically 59% and equipment revenue rose 48% from a low base.
As Geoff said, this rebound is partly a reflection of the annualization of the quarters heavily affected by the COVID-19 pandemic. We also observed that high-end automobile and construction applications were stronger than expected. Automotive producers are still operating below full capacity due to the semiconductor shortage but the demand environment is intact. So we believe that demand is simply being pushed out possibly even into 2022.
In the meantime, we are also experiencing promising project wins outside the auto market and strong demand for our sustainability-focused solutions. As Geoff touched earlier, we have seen an increase in interest for our sustainability-related products. As CFO, it's worth noting that our preparation to meet this opportunity rests on many years of development and investment. For example, the cumulative spend on R&D for the Covertron system has been nearly $20 million, spread over more than a decade.
As we look to earnings, GMF adjusted EBITDA hit $33 million in the quarter and the adjusted margin was 25.8%. The growth in adjusted EBITDA reflects our strong operating leverage partially offset by the higher freight expenses as a result of the well-known supply chain disruptions and the mentioned higher material inflation. The recovery of the adjusted EBITDA margin to 25.8% is thanks to similar effects, and it's worth noting that we're now back on the path to normalized margins. Let's now move to Slide 7.
We generated strong free cash flow of $86 million before debt service, returning to adjusted cash flow conversion rate more in line with our long-term targets of greater than 60%. The strong cash flow was also a function of our efficient working capital management, with working capital at 16% of revenues in the second quarter as well as our efficient capex, which was 2% of revenue. Please note that we have a typical seasonality to our capex, with the majority coming in the second half of the year. So although the spend as a percentage of revenue was lower than our full year guidance, we're fully aligned with our internal expectations.
As a result, at quarter end, we had $245 million of cash and a revolving credit facility of $233 million available. So in total,
nic growth of 21%, a favorable palladium impact of 4% and an 8% benefit from FX translation. Organic growth in chemistry revenue for Electronics was 9% in the quarter, underpinned by the strong growth in the smartphone market as well as sustained growth in the high-performance PCB and semiconductor-related businesses.
As mentioned in May, this growth has been anticipated, and we are pleased to see it unfold. That said, please keep in mind that 2020 saw some shifts in typical seasonality. Work from home created stronger demand for laptops in the third quarter and a well-known OEM shifted its product launch patent into the fourth quarter. As we lap this quarter, the base effect may cause mathematically lower growth rates compared to what we reported in the first half of 2021.
Electronic equipment sales enjoyed another outstanding quarter with organic revenue up 115%. The demand stems from the sources we have outlined previously, the full transition to 5G for the smartphone manufacturers with a high demand for computing. Our next-generation machines are in high demand as OEMs and PCB manufacturers seek to meet consumer demand. Electronics generated $85 million of adjusted EBITDA in the quarter, a $23 million or 36% improvement over the prior year period, primarily driven by the strong organic volume growth and our lean cost structure.
Margin was 34.3% in the quarter, up 20 basis points, which is a reflection of the robust organic volume growth, partially offset by product mix effects from high equipment sales and the palladium pass-through. Moving to Slide 6 now. GMF total revenue grew 71% to $129 million in the second quarter, comprised of organic growth of 59%, a 1% positive impact from palladium and an 11% tailwind from FX. From a mix perspective, chemistry revenues grew organically 59% and equipment revenue rose 48% from a low base.
As Geoff said, this rebound is partly a reflection of the annualization of the quarters heavily affected by the COVID-19 pandemic. We also observed that high-end automobile and construction applications were stronger than expected. Automotive producers are still operating below full capacity due to the semiconductor shortage but the demand environment is intact. So we believe that demand is simply being pushed out possibly even into 2022.
 In the meantime, we are also experiencing promising project wins outside the auto market and strong demand for our sustainability-focused solutions. As Geoff touched earlier, we have seen an increase in interest for our sustainability-related products. As CFO, it's worth noting that our preparation to meet this opportunity rests on many years of development and investment. For example, the cumulative spend on R&D for the Covertron system has been nearly $20 million, spread over more than a decade.
As we look to earnings, GMF adjusted EBITDA hit $33 million in the quarter and the adjusted margin was 25.8%. The growth in adjusted EBITDA reflects our strong operating leverage partially offset by the higher freight expenses as a result of the well-known supply chain disruptions and the mentioned higher material inflation. The recovery of the adjusted EBITDA margin to 25.8% is thanks to similar effects, and it's worth noting that we're now back on the path to normalized margins. Let's now move to Slide 7.
We generated strong free cash flow of $86 million before debt service, returning to adjusted cash flow conversion rate more in line with our long-term targets of greater than 60%. The strong cash flow was also a function of our efficient working capital management, with working capital at 16% of revenues in the second quarter as well as our efficient capex, which was 2% of revenue. Please note that we have a typical seasonality to our capex, with the majority coming in the second half of the year. So although the spend as a percentage of revenue was lower than our full year guidance, we're fully aligned with our internal expectations.
As a result, at quarter end, we had $245 million of cash and a revolving credit facility of $233 million available. So in total,